,illu/ration3 ,,plate ,i ,frontispiece ,,gem-,,/ones ,,gem-,,/ones ,,& ,,_! ,,di/9ctive ,,*>act]s ,,by ,g4 ,f4 ,,h]b]t ,,smi? ,m4,a41 ,d4,sc4 ,,( ,,! ,,briti% ,,museum 7,,natural ,,hi/ory7 ,,) ,,_m ,,diagrams ,,& ,,?irty-,,two ,,plates ,,( ,,:i* ,,?ree ,,are ,,9 ,,col\r ,,?ird ,,edition ,,me?u5 ,,co4 ,,ltd4 #cf ,,essex ,,/reet ,w4,c4 ,,london ,fir/ ,publi%$ ,m>* #ba/ #aiaj ,second ,edition ,june #aiac ,?ird ,edition #aiai ,,preface ,9 ?is edition ! opportunity has be5 tak5 to correct a few mispr9ts & mi/akes t h be5 discov]$ 9 ! fir/1 & to alt] slightly "o or two p>agraphs1 b o!rwise no *ange has be5 made4 ,g4 ,f4 ,h4 ,s4 ,,w&swor? ,,common1 ,s4,w4 ,,preface ,,to ,,! ,,fir/ ,,edition ,x has be5 my endeav\r to provide 9 ?is book a concise1 yet suffici5tly complete1 acc\nt ( ! physical *>act]s ( ! m9]al species :i* f9d s]vice 9 jewell]y1 & ( ! me?ods available = det]m9+ _! pr9cipal physical con/ants to enable a read]1 ev5 if previ\sly unacqua9t$ ) ! subject1 to h at h& all ! in=mation requisite = ! sure id5tification ( any cut /one :i* may be met )4 ,= sev]al reasons ,i h dealt some:at m fully ) ! bran*es ( sci5ce closely connect$ ) ! prop]ties ( cry/alliz$ matt] ?an has be5 cu/om>y hi!rto 9 ev5 ! mo/ compreh5sive books on preci\s /ones4 ,rec5t ye>s h witness$ _m *anges 9 ! jewell]y _w4 ,gem-/ones are no long] entirely drawn f a few well-m>k$ m9]al species1 :i* are1 on ! :ole1 easily di/+ui%able f "o ano!r1 & x becomes increas+ly difficult = ev5 ! mo/ exp]i5c$ eye to recognize a cut /one ) un]r+ c]ta9ty4 ,s long z ! only confusion lay betwe5 preci\s /ones & pa/e imitations an ord9>y file 0 ! solit>y piece ( app>atus requir$ by ! jewell]1 b n[ rec\rse mu/ be _h to m discrim9ative te/s1 su* z ! refractive index or ! specific gravity1 ! det]m9ation ( :i* calls = a little k & skill4 ,concurr5tly1 a ke5] int]e/ is be+ tak5 9 ! sci5tific aspect ( gem-/ones by ! public at l>ge1 :o are attract$ to !m ma9ly by /hetic consid]ations4 ,:ile ! treatm5t has be5 kept z simple z possible1 te*nical expressions1 :]e necess>y1 h n be5 avoid$1 b _! mean+s h be5 expla9$1 & x is hop$ t _! use w n prove /umbl+-blocks to ! novice4 ,unfamili> words ( ?is k9d (t5 give a =bidd+ air to a new subject1 b !y are us$ m]ely to avoid circumlocution1 & n1 l ! incantations ( a wiz>d1 to veil ! difficulties 9 /ill deep] gloom4 ,= actual practical "w ! pages on ! refractomet] & its use & ! me?od ( heavy liquids = ! det]m9ation ( specific gravities1 & ! tables ( physical con/ants at ! end ( ! book1 ) occasional ref]5ce1 9 case ( d\bt1 to ! descriptions ( ! sev]al species alone are requir$2 o!r me?ods--su* z ! prismatic mode ( measur+ refractive indices1 or ! hydro/atic way ( f9d+ specific gravities--:i* f9d a place 9 ! ord9>y curriculum ( a physics c\rse are describ$ 9 _! special application to gem-/ones1 b !y are n s suitable = work%op practice4 ,s9ce ! scope ( ! book is conf9$ ma9ly to ! /ones z !y appe> on ! m>ket1 little has be5 said ab\t _! geological occurr5ce2 ! case ( diamond1 h[ev]1 is ( exceptional int]e/ & has be5 m fully treat$4 ,! weights /at$ = ! hi/orical diamonds are ^? usually publi%$1 & are probably 9 _m in/ances f> f correct1 b !y s]ve to give an idea ( ! sizes ( ! /ones2 ! ,engli% c>at is ! unit us$1 & ! numb]s mu/ be increas$ by ab\t #b p] c5t4 if ! weights be express$ 9 metric c>ats4 ,! prices quot$ = ! v>i\s species mu/ only be reg>d$ z approximate1 s9ce !y may *ange f ye> to ye>1 or ev5 day to day1 accord+ to ! /ate ( trade & ! :im ( fa%ion4 ,! diagram on ,plate ,,ii & mo/ ( ! cry/al draw+s 7 made by me4 ,! rema9+ draw+s are ! "w ( ,mr4 ,h4 ,h4 ,p5ton4 ,he likewise prep>$ ! col\r$ draw+s ( cut /ones :i* appe> on ! ?ree col\r$ plates1 8 models1 ) two exceptions1 be+ select$ f ! cut specim5s 9 ! ,m9]al ,collection ( ! ,briti% ,museum by p]mission ( ! ,tru/ees4 ,un=tunately1 ! difficulties t /ill beset ! reproduction ( pictures 9 col\r h prev5t$ full ju/ice be+ done to ! fai?fulness ( 8 bru%4 ,i highly appreciate ! int]e/ he took 9 ! "w1 & ! c>e & skill ) :i* x 0 execut$4 ,my ?anks are due to ! ,de ,be]s ,consolidat$ ,m9es ,co4 ,ltd41 & to ,sir ,h5ry ,a4 ,mi]s1 ,f4,r4,s41 ,pr9cipal ( ! ,univ]sity ( ,london1 = ! illu/rations ( ! ,kimb]ley & ,wesselton diamond m9es1 & ( ! me?ods & app>atus employ$ 9 break+ up & conc5trat+ ! blue gr\nd2 to ,messrs4 ,i4 ,j4 ,ass*] ,co4 = ! use ( ! photograph ( ! ,cull9an diamond2 to ,mr4 ,j4 ,h4 ,/ew>d = ! loan ( ! block ( ! refractomet]2 & to ,mr4 ,h4 ,w4 ,atk9son = ! illu/ration ( ! diamond-sort+ ma*9e4 ,my colleague1 ,mr4 ,w4 ,campbell ,smi?1 ,b4,a41 has mo/ k9dly read ! pro(-%eets1 & has be5 ( great assi/ance 9 _m ways4 ,i hope t1 ?anks to 8 invaluable help1 ! errors 9 ! book :i* may h escap$ notice w prove few 9 numb] & unimportant 9 "*4 ,to ,mr4 ,edw>d ,hopk9s ,i owe an especial debt ( gratitude = 8 *e]ful read9ess to assi/ me 9 any way 9 8 p[]4 ,he read bo? ! manuscript & ! pro(-%eets1 & ! in=mation ) reg>d to ! comm]cial & practical side ( ! subject 0 v l>gely suppli$ by him4 ,he also plac$ at my s]vice a l>ge numb] ( photographs1 "s ( :i*--= in/ance1 ^? illu/rat+ ! cutt+ ( /ones--he _h specially tak5 = me1 & he procur$ = me ! jewell]y designs %[n on ,plates ,,iv & ,v4 ,if ?is book be f\nd by ^? engag$ 9 ! jewell]y trade helpful 9 _! ev]yday "w1 & if x wak5s 9 read]s g5]ally an appreciation ( ! v>iety ( beautiful m9]als suitable = gems1 & an int]e/ 9 ! wondr\s qualities ( cry/alliz$ sub/ances1 ,i %all be m ?an satisfi$4 ,g4 ,f4 ,h4 ,s4 ,,w&swor? ,,common1 ,s4,w4 ,,cont5ts ,,*ap4 ,,page ,i4 ,,introduction #a ,,"p ,i--,,section ,a ,,! ,,*>act]s ,,( ,,gem-,,/ones ,,ii4 ,,cry/all9e ,,=m #f ,,iii4 ,,reflection1 ,,refraction1 ,,& ,,disp]sion #ad ,,iv4 ,,measurem5t ,,( ,,refractive ,,indices #ba ,v4 ,,lu/re ,,& ,,%e5 #cg ,,vi4 ,,d\ble ,,refraction #dj ,,vii4 ,,absorption ,,effects3 ,,col\r1 ,,di*roism1,,etc4 #ec ,,viii4 ,,specific ,,gravity #fc ,,ix4 ,,h>dness ,,& ,,cleavability #gh ,x4 ,,electrical ,,*>act]s #hb ,,"p ,i--,,section ,b ,,! ,,te*nology ,,( ,,gem-,,/ones ,,xi4 ,,unit ,,( ,,weight #hd ,,xii4 ,,fa%ion+ ,,( ,,gem-,,/ones #hh ,,xiii4 ,,nom5clature ,,( ,,preci\s ,,/ones #aji ,,xiv4 ,,manufactur$ ,,/ones #aac ,,xv4 ,,imitation ,,/ones #abd ,,"p ,,ii--,,section ,a ,,preci\s ,,/ones ,,xvi4 ,,diamond #abh ,,xvii4 ,,occurr5ce ,,( ,,diamond #acg ,,xviii4 ,,hi/orical ,,diamonds #aeg ,,xix4 ,,corundum 7,sapphire1 ,ruby7 #agb ,,xx4 ,,b]yl 7,em]ald1 ,aquam>9e1 ,morganite7 #ahd ,,"p ,,ii--,,section ,b ,,semi-,,preci\s ,,/ones ,,xxi4 ,,topaz #aig ,,xxii4 ,,sp9el 7,balas-,ruby1 ,rubicelle7 #bjc ,,xxiii4 ,,g>net #bjg 7a7 ,,hessonite 7,grossul>1 ,c9namon-,/one1 ,hyac9?1 ,jac9?7 #baa 7b7 ,,pyrope 7#8,cape-,ruby'7 #bab 7c7 ,,rhodolite #bad 7d7 ,,alm&9e 7,c>buncle7 #bad 7e7 ,,spess>tite #baf 7f7 ,,&radite 7,demantoid1 ,topazolite1 #8,oliv9e'7 #baf 7g7 ,,uv>ovite #bah ,,xxiv4 ,,t\rmal9e 7,rubellite7 #bai ,,xxv4 ,,p]idot #bbe ,,xxvi4 ,,zircon 7,j>goon1 ,hyac9?1 ,jac9?7 #bbh ,,xxvii4 ,,*rysob]yl 7,*rysolite1 ,cat's-,eye1 ,cymophane1 ,alex&rite7 #bcc ,,xxviii4 ,,qu>tz 7,rock-,cry/al1 ,ame?y/1 ,citr9e1 ,cairngorm1 ,cat's-,eye1 ,tig]'s-,eye7 #bch ,,xxix4 ,,*alc$ony1 ,,agate1 ,,etc4 #bdf ,,xxx4 ,,opal 7,:ite ,opal1 ,black ,opal1 ,fire-,opal7 #bdi ,,xxxi4 ,,felsp> 7,moon/one1 ,sun/one1 ,labradorite1 ,amazon-,/one7 #bed ,,xxxii4 ,,turquoise1 ,,odontolite1 ,,v>iscite #beg ,,xxxiii4 ,,jade 7,,nephrite ,,or ,,gre5/one1 ,jadeite7 #bfj ,,xxxiv4 ,,spodum5e 7,kunzite1 ,hidd5ite71 ,,iolite1 ,,b5itoite #bfe ,,xxxv4 ,,euclase1 ,,ph5akite1 ,,b]yllonite #bfi ,,xxxvi4 ,,en/atite 7#8,gre5 ,g>net'71 ,,diopside1 ,,kyanite1 ,,&alusite1 ,,idocrase1 ,,epidote1 ,,sph5e1 ,,ax9ite1 ,,prehnite1 ,,apatite1 ,,dioptase #bga ,,xxxvii4 ,,cassit]ite1 ,,anatase1 ,,pyrites1 ,,hematite #bha ,,xxxviii4 ,,obsidian1 ,,moldavite #bhc ,,"p ,,ii--,,section ,c ,,ornam5tal ,,/ones ,,xxxix4 ,,fluor1 ,,lapis ,,lazuli1 ,,sodalite1 ,,violane1 ,,rhodonite1 ,,azurite1 ,,mala*ite1 ,,?ulite1 ,,m>ble1 ,,apophyllite1 ,,*rysocolla1 ,,/eatite ,,or ,,soap/one1 ,,me]s*aum1 ,,s]p5t9e #bhe ,,"p ,,ii--,,section ,d ,,organic ,,products ,,xl4 ,,pe>l1 ,,coral1 ,,amb] #bia ,,tables ,i4 ,,*emical ,,composition ,,( ,,gem-,,/ones #cjj ,,ii4 ,,col\r ,,( ,,gem-,,/ones #cja ,,iii4 ,,refractive ,,indices ,,( ,,gem-,,/ones #cjb ,,iv4 ,,col\r-,,disp]sion ,,( ,,gem-,,/ones #cjc ,v4 ,,"* ,,( ,,! ,,refraction ,,( ,,gem-,,/ones #cjc ,,vi4 ,,di*roism ,,( ,,gem-,,/ones #cjd ,,vii4 ,,specific ,,gravities ,,( ,,gem-,,/ones #cje ,,viii4 ,,degrees ,,( ,,h>dness ,,( ,,gem-,,/ones #cje ,,ix4 ,,data #cjf ,,index #cjg ,,li/ ,,( ,,plates ,,page ,i4 ,,gem-,,/ones 79 col\r7 ,frontispiece ,,ii4 ,,refractive ,,index ,,diagram #cf ,,iii4 ,,int]f]5ce ,,figures #dh ,,iv4 ,,jewell]y ,,designs #fb ,v4 ,,jewell]y ,,designs #hh ,,vi4 ,,appliances ,,us$ ,,= ,,poli%+ ,,diamonds #ajb ,,vii4 ,,poli%+ ,,diamonds #ajc ,,viii4 ,,slitt+ ,,& ,,poli%+ ,,col\r$ ,,/ones #ajd ,,ix4 ,,facet+ ,,ma*9e #aje ,x4 ,,lapid>y',s ,,work%op ,,& ,,(fice ,,9 ,,engl& #ajf ,,xi4 ,,lapid>y',s ,,work%op ,,9 ,,russia #ajg ,,xii4 ,,fr5* ,,family ,,cutt+ ,,/ones #ajh ,,xiii4 ,,indian ,,lapid>y #aji ,,xiv4 ,,bl[pipe ,,us$ ,,= ,,! ,,manufacture ,,( ,,rubies ,,& ,,sapphires #aah ,,xv4 ,,kimb]ley ,,m9e1 #ahga #adj ,,xvi4 ,,kimb]ley ,,m9e1 #ahgb #ada ,,xvii4 ,,kimb]ley ,,m9e1 #ahgd #adb ,,xviii4 ,,kimb]ley ,,m9e1 #ahha #adc ,,xix4 ,,kimb]ley ,,m9e ,,at ,,! ,,pres5t ,,day #add ,,xx4 ,,wesselton 7op57 ,,m9e #ade ,,xxi4 ,,load+ ,,! ,,blue ,,gr\nd ,,on ,,! ,,floors1 ,,& ,,pl\gh+ ,,x ,,ov] #adf ,,xxii4 ,,wa%+-,,ma*9es ,,= ,,conc5trat+ ,,! ,,blue ,,gr\nd #adg ,,xxiii4 ,,diamond-,,sort+ ,,ma*9es #adh ,,xxiv4 ,,kafirs ,,pick+ ,,out ,,diamonds #adi ,,xxv4 ,,cull9an ,,diamond 7natural size7 #afh ,,xxvi4 ,,l>ge ,,aquam>9e ,,cry/al 7"o-six? natural size71 ,,f\nd ,,at ,,m>ambaya1 ,,m9as ,,g]aes1 ,,brazil #aif ,,xxvii4 ,,gem-,,/ones 79 col\r7 #bbf ,,xxviii4 ,,opal ,,m9es1 ,,:ite ,,cliffs1 ,,new ,,s\? ,,wales #beb ,,xxix4 ,,gem-,,/ones 79 col\r7 #bef ,,xxx4 ,,natives ,,drill+ ,,pe>ls #bid ,,xxxi4 ,,metal ,,figures ,,( ,,buddha ,,ins]t$ ,,9 ,a ,,pe>l-,,oy/] #bif ,,xxxii4 ,,sections ,,( ,,culture ,,pe>l #big ,,gem-,,/ones ,,*apt] ,i ,,introduction ,beauty1 durability1 & r>ity3 su* are ! ?ree c>d9al virtues ( a p]fect gem-/one4 ,/ones lack+ any ( !m _c aspire to a high place 9 ! ranks ( preci\s /ones1 al?\gh x does n necess>ily foll[ t !y are ( no use = ornam5tal purposes4 ,! case ( pe>l1 :i*1 ?\gh n prop]ly includ$ among gem-/ones1 be+ directly produc$ by liv+ ag5cy1 yet holds an hon\r$ place 9 jewell]y1 con/itutes to "s ext5t an exception1 s9ce its inconte/able beauty atones = its comp>ative want ( durability4 ,t a gem-/one %\ld be a delight to ! eye is a truism t ne$ n be lab\r$2 = su* is its :ole raison d'tre4 ,! memb]s ( ! ,m9]al ,k+dom t f9d s]vice 9 jewell]y may be divid$ into ?ree gr\ps1 accord+ z !y are transp>5t1 transluc5t1 or opaque4 ,( ^! ! fir/1 :i* is by f> ! l>ge/ & ! mo/ important1 may itself be fur!r sub-divid$ into two sections3 /ones :i* are devoid ( col\r1 & /ones :i* are t9t$4 ,among ! =m]1 diamond reigns supreme1 s9ce x alone possesses t m>vell\s #8fire1' oscillat+ ) e movem5t f heav5ly blue to gl[+ r$1 :i* is s highly e/eem$ & s mu* bes\ght4 ,o!r /ones1 su* z #8fir$' zircon1 :ite sapphire1 :ite topaz1 & rock-cry/al1 may dazzle ) brilliancy ( light reflect$ f ! surface or emitt$ f ! int]ior1 b none ( !m1 l diamond1 gl[ ) my/]i\s gleams4 ,no h9t ( col\r1 save p]haps a trace ( ! blue ( /eel1 c be tol]at$ 9 /ones ( ?is category2 above all is a t\* ( ! jaundice hue ( yell[ abhorr$4 ,x taxes all ! skill ( ! lapid>y to assure t ! disposition ( ! facets be su* z to reveal ! full spl5d\r ( ! /one4 ,a col\r$ /one1 on ! o!r h&1 dep5ds = its attractiv5ess m ^u its intr9sic hue ?an ^u ! mann] ( its cutt+4 ,! t9t mu/ n be too light or too d>k 9 %ade3 a /one t has b>ely any col\r has little int]e/1 & "o :i* is too d>k appe>s almo/ opaque & black4 ,! lapid>y c to "s ext5t rem$y ^! defects by cutt+ ! =m] deep & ! latt] %all[4 ,9 c]ta9 curi\s /ones--= in/ance t\rmal9e--! transp>5cy1 & 9 o!rs--su* z ruby1 sapphire1 & "o ( ! rec5t additions to ! gem _w1 kunzite--! col\r1 v>ies consid]ably 9 diff]5t directions4 ,! col\rs t are mo/ admir$--! fi]y r$ ( ruby1 ! royal blue ( sapphire1 ! v]dant gre5 ( em]ald1 & ! gold5 yell[ ( topaz--are pure t9ts1 & ! absorption spectra correspond+ to !m are on ! :ole cont9u\s & (t5 re/rict$4 ,!y !re=e reta9 ! purity ( _! col\r ev5 9 artificial light1 ?\gh c]ta9 sapphires transmit a relatively l>g] am\nt ( r$1 & consequ5tly turn purple at night4 ,( ! small gr\p ( transluc5t /ones :i* pass light1 b are n cle> en\gh to be se5 ?r\gh1 ! mo/ important is opal4 ,x & c]ta9 o!rs ( ! gr\p owe _! m]it to ! same optical effect z t *>act]iz+ soap-bubbles1 t>ni%$ /eel1 & s =?1 & n to any intr9sic coloration4 ,ano!r set ( /ones--moon/one & ! />-/ones--reflect light f ! int]ior m or less regul>ly1 b n 9 su* a way z to produce a play ( col\r4 ,! la/ gr\p1 :i* comprises opaque /ones1 has a s+le repres5tative among ord9>y gem-/ones1 namely1 turquoise4 ,9 ?is case light is scatt]$ & reflect$ f lay]s imm$iately contigu\s to ! surface1 & ! col\r is due to ! result+ absorption4 ,! app>5t d>kness ( a deep-col\r$ /one foll[s f a diff]5t cause3 ! light pass+ into ! /one is :olly absorb$ )9 x1 &1 s9ce none is emitt$1 ! /one appe>s black4 ,! claims ( turquoise are ma9ta9$ by ! blue v>iety2 !re is little dem& = /ones ( a gre5i% t+e4 ,x is evid5tly desirable t any /ones us$ 9 jewell]y %\ld be able to resi/ ! me*anical & *emical actions ( ev]yday life4 ,no "o is anxi\s to replace jewels e few ye>s1 & ! mo/ valuable /ones are expect$ to endure = all "t4 ,! me*anical abrasion is caus$ by ! m9ute gra9s ( s& t are conta9$ 9 ord9>y du/1 & gem-/ones %\ld be at lea/ z h>d z !y--a condition fulfill$ by all ! pr9cipal species ) ! exception ( opal1 turquoise1 p]idot1 & demantoid4 ,s9ce ! beauty ( ! fir/ nam$ does n dep5d on ! brilliancy ( its poli%1 scrat*es on ! surface are n ( mu* importance2 fur!r1 all f\r are only slightly s(t] ?an s&4 ,x may be not$ t ! s(tness ( pa/e /ones1 ap>t f any objections t may be felt to ! use ( imitations1 r5d]s !m unsuitable = jewell]y purposes4 ,! only /ones t are likely to be *emically affect$ 9 ! c\rse ( we> are ^? :i* are 9 ! slighte/ degree por\s4 ,x is haz>d\s to imm]se turquoises 9 liquids1 ev5 9 wat]1 le/ ! blui% gre5 col\r be oxidiz$ to ! despis$ yell[i% hue4 ,! risk ( damage to opals1 moon/ones1 & />-/ones by ! p5etration ( dirt or grease into ! int]ior ( ! /ones is less1 b is n :olly negligible4 ,simil> rem>ks apply ) ev5 great] =ce to pe>ls4 ,_! *>m1 :i* is due to a peculi> surface-play ( light1 might be de/roy$ by contam9ation ) grease1 ink1 or simil> matt]2 !y are1 moreov]1 s(t4 ,= bo? reasons _! use 9 r+s is mu* to be deprecat$4 ,no?+ c be m unsightly ?an ! d+y appe>ance ( a pe>l r+ aft] a few ye>s' we>4 ,x _c be ga9said t mank9d pref]s ! r>e to ! beautiful1 & :at is )9 rea* ( all is lightly e/eem$4 ,x is = ?is reason t g>net & moon/one lie "u a cl\d4 ,pur*as]s c readily be f\nd = a #8,cape-ruby' or an #8oliv9e1' b n = a g>net2 g>nets are s common1 is ! usual rem>k4 ,nev]!less1 ! /ones m5tion$ are really g>nets4 ,if sci5ce succe$$ 9 manufactur+ diamonds at ! co/ ( %ill+s in/ead ( ! p\nds t are n[ ask$ = ,nature's products--n t su* a prospect is at all probable or ev5 feasible--we might expect !m to vani% entirely f fa%ionable jewell]y4 ,a c>eful /udy ( ! %[cases ( ! mo/ ext5sive jewell]y e/abli%m5t br+s to light ! fact t1 despite ! app>5t pr(usion1 ! numb] ( diff]5t species repres5t$ is re/rict$4 ,diamond1 ruby1 em]ald1 sapphire1 pe>l1 opal1 turquoise1 topaz1 ame?y/ are all t are ord9>ily ask$ =4 ,yet1 z lat] pages w %[1 !re are _m o!rs wor?y ( consid]ation2 two among !m--p]idot & t\rmal9e--are1 inde$1 sl[ly becom+ kn[n4 ,= ! fir/ five ( ! /ones m5tion$ above1 ! dem& is relatively /eady1 & v>ies absolutely only ) ! pur*as+ p[] ( ! _w2 b a less] kn[n /one may sudd5ly spr+ into prom95ce ow+ to ! caprice ( fa%ion or ! pref]5ce ( "s great lady or lead] ( fa%ion4 ,n _m ye>s ago1 = in/ance1 violet 0 ! fav\rite col\r = ladies' dresses1 & consequ5tly ame?y/s 7 mu* worn to mat*1 b ) ! *ange ( fa%ion !y spe$ily sank to _! =m] obscurity4 ,ano!r /one may p]haps figure at "s royal w$d+2 = a brief :ile x becomes ! vogue1 & aft]w>ds is seldom se54 ,except t diamond1 ruby1 em]ald1 & sapphire1 &1 we %\ld add1 pe>l1 may indisputably be consid]$ to occupy ! fir/ rank1 x is impossible to =m ! gem-/ones 9 any /rict ord]4 ,e g5]ation sees "s *ange4 ,! value ( a /one is aft] all m]ely :at x w fet* 9 ! op5 m>ket1 & its arti/ic m]its may be a matt] ( op9ion4 ,! famili> aphorism1 de gu/ibus non e/ disput&um1 is a w>n+ n to enl>ge ^u ?is po9t4 ,,"p ,i--,,section ,a ,,! ,,*>act]s ,,( ,,gem-,,/ones ,,*apt] ,,ii ,,cry/all9e ,,=m ,) ! s+le exception ( opal1 ! :ole ( ! pr9cipal m9]al species us$ 9 jewell]y are di/+ui%$ f glass & simil> sub/ances by "o fundam5tal diff]5ce3 !y are cry/alliz$ matt]1 & ! atoms compos+ !m are regul>ly arrang$ ?r\gh\t ! /ructure4 ,! words cry/al & glass are employ$ 9 sci5ce 9 s5ses diff]+ consid]ably f ^? 9 popul> use4 ,! =m] ( !m is d]iv$ f ! ,greek ^w 1 mean+ ice1 & 0 at "o "t us$ 9 t s5se4 ,= in/ance1 ! old f\rte5?-c5tury read+ ( ,psalm cxlvii4 #ag1 :i* appe>s 9 ! au?oriz$ v]sion z 8,he give? 8 ice l morsels10 ran 8,he s5dis 8 kri/all z morcels40 ,x 0 also appli$ to ! beautiful1 lu/r\s qu>tz f\nd among ! et]nal sn[s ( ! ,alps1 s9ce1 on acc\nt ( _! limpidity1 ^! /ones 7 suppos$1 z ,pl9y tells u1 to consi/ ( wat] congeal$ by ! extreme cold ( ^? regions2 su* at ! pres5t day is ! ord9>y mean+ ( ! ^w4 ,b1 :5 e>ly inve/igators discov]$ t a salt solution on evaporation left beh9d gr\ps ( sl5d] gli/5+ prisms1 ea* v simil> to ! re/1 !y naturally--?\gh1 z we n[ "k1 wrongly--reg>d$ !m z repres5t+ yet ano!r =m ( congeal$ wat]1 & appli$ ! same ^w to su* sub/ances4 ,subsequ5t rese>* has %[n t ^! salts1 z well z m9]al sub/ances occurr+ ) natural faces 9 nature1 h 9 common ! fundam5tal prop]ty ( regul>ity ( arrangem5t ( ! con/itu5t atoms1 & sci5ce !re=e def9es by ! ^w cry/al a sub/ance 9 :i* ! /ructure is uni=m ?r\gh\t1 & all ! simil> atoms compos+ x are arrang$ ) reg>d to ! /ructure 9 a simil> way4 ,! o!r ^w is yet m famili>2 x d5otes ! transp>5t1 lu/r\s1 h>d1 & brittle sub/ance produc$ by ! fusion ( s& ) soda or pota% or bo? :i* fills our w9d[s & s]ves a v>iety ( useful purposes4 ,rese>* has %[n t glass1 ?\gh app>5tly s uni=m 9 "*1 has 9 reality no regul>ity ( molecul> arrangem5t4 ,x is1 9 fact1 a k9d ( mosaic ( atoms1 huddl$ toge!r anyh[1 b s irregul> is its irregul>ity t x simulates p]fect regul>ity4 ,sci5ce uses ! ^w glass 9 ?is wid5$ mean+4 ,two sub/ances may1 z a matt] ( fact1 h ! same *emical composition1 & "o be a cry/al & ! o!r a glass4 ,= example1 qu>tz1 if heat$ to a high temp]ature1 may be fus$ & conv]t$ into a glass4 ,! diff]5ce 9 ! two types ( /ructure may be illu/rat$ by a comp>ison betwe5 a regim5t ( soldi]s drawn up on p>ade & an ord9>y cr[d ( p4 ,! cry/all9e =m is a visible sign ( ! molecul> arrangem5t1 & is intimately associat$ ) ! directional physical prop]ties1 su* z ! optical *>act]s1 cleavage1 etc4 ,a /udy ( x is n only ( int]e/ 9 itself1 b also ( great importance to ! lapid>y :o wi%es to cut a /one to ! be/ advantage1 & x is1 moreov]1 ( s]vice 9 di/+ui%+ /ones :5 9 ! r\gh /ate4 ,illu/ration3 ,,fig4 #a4--;,cubo-,octah$ra4 ,! developm5t ( natural faces on a cry/al is f> f be+ haphaz>d1 b is gov]n$ by ! condition t ! angles betwe5 simil> faces1 :e!r on ! same cry/al or on diff]5t cry/als1 are equal1 h[ev] v>y+ may be ! %apes & ! relative sizes ( ! faces 7,fig4 #a71 & by ! t5d5cy ( ! faces b\nd+ ! cry/al to fall into s]ies ) p>allel edges1 su* s]ies be+ t]m$ zones4 ,ea* species has a *>act]i/ic type ( cry/allization1 :i* may be ref]r$ to "o ( ! foll[+ six sy/ems3-- #a4 ,cubic4--,cry/als 9 ?is sy/em c be ref]r$ to ?ree edges1 :i* are mutually at "r angles1 & 9 :i* ! directional *>act]s are id5tical 9 value4 ,^! pr9cipal edges are kn[n z axes4 ,"s typical =ms are ! cube 7,fig4 #b71 *>act]i/ic ( fluor2 ! octah$ron 7,fig4 #c71 *>act]i/ic ( diamond & sp9el2 ! dodecah$ron 7,fig4 #d71 *>act]i/ic ( g>net2 & ! triakisoctah$ron1 or ?ree-fac$ octah$ron 7,fig4 #e74 ,illu/ration3 ,,fig4 #b4--;,cube4 ,illu/ration3 ,,fig4 #c4--,octah$ron4 ,illu/ration3 ,,fig4 #d4--;,dodecah$ron4 ,all cry/als belong+ to ?is sy/em are s+ly refractive4 #b4 ,tetragonal4--,su* cry/als c be ref]r$ to ?ree axes1 :i* are mutually at "r angles1 b 9 only two ( !m are ! directional *>act]s id5tical4 ,a typical =m is a f\r-sid$ prism1 mm1 ( squ>e section1 t]m9at$ by f\r triangul> faces1 p 7,fig4 #f71 ! usual %ape ( cry/als ( zircon & idocrase4 ,illu/ration3 ,,fig4 #e4--,triakisoctah$ron1 or ,?ree-fac$ ,octah$ron4 ,illu/ration3 ,,fig4 #f4--,tetragonal ,cry/al4 ,cry/als belong+ to ?is sy/em are d\bly refractive & uniaxial1 i4e4 !y h "o direction ( s+le refraction 7cf4 p4 #de71 :i* is p>allel to ! unequal edge ( ! ?ree m5tion$ above4 ,illu/ration3 ,,fig4 #g4--,two alt]native sets ( ,axes 9 ! ,hexagonal ,sy/em4 #c4 ,hexagonal4--,su* cry/als c be ref]r$ alt]natively ei!r to a set ( ?ree axes1 ,x1 ,y1 ,z 7,fig4 #g71 :i* lie 9 a plane p]p5dicul> to a f\r?1 ,h1 & are mutually incl9$ at angles ( #fj1 or to a set ( ?ree1 a1 b1 c1 :i* are n at "r angles z 9 ! cubic sy/em1 b 9 :i* ! directional *>act]s are id5tical4 ,! f\r? axis 9 ! fir/ arrangem5t is equally incl9$ to ea* 9 ! second set ( axes4 ,_m important species cry/allize 9 ?is sy/em--corundum 7sapphire1 ruby71 b]yl 7em]ald1 aquam>9e71 t\rmal9e1 qu>tz1 & ph5akite4 ,! cry/als usually display a six-sid$ prism1 t]m9at$ by a s+le face1 c1 p]p5dicul> to ! edge ( ! prism m 7,fig4 #h71 e4g4 em]ald1 or by six or twelve incl9$ faces1 p 7,fig4 #i71 e4g4 qu>tz1 cry/als ( :i* are s con/ant 9 =m z to be ! mo/ famili> 9 ! ,m9]al ,k+dom4 ,t\rmal9e cry/als 7,fig4 #aj7 are peculi> because ( ! fact t (t5 "o end is obvi\sly to ! eye flatt] ?an ! o!r4 ,illu/ration3 ,,figs4 #h-aj4--;,hexagonal ,cry/als4 ,cry/als belong+ to ?is sy/em are also d\bly refractive & uniaxial1 ! direction ( s+le refraction be+ p>allel to ! f\r? axis m5tion$ above1 & !re=e also p>allel to ! prism edge4 ,h5ce deeply col\r$ t\rmal9e1 :i* /rongly absorbs ! ord9>y ray1 mu/ be cut ) ! table-facet p>allel to ! edge ( ! prism4 ,illu/ration3 ,,fig4 #aa4--,relation ( ! two directions ( s+le ,refraction to ! ,axes 9 an ,or?orhombic ,cry/al4 #d4 ,or?orhombic4--,su* cry/als c be ref]r$ to ?ree axes1 :i* are mutually at "r angles1 b 9 :i* ea* ( ! directional *>act]s are diff]5t4 ,! cry/als are usually prismatic 9 %ape1 "o ( ! axes be+ p>allel to ! prism edge4 ,topaz1 p]idot1 & *rysob]yl are ! mo/ important species cry/alliz+ 9 ?is sy/em4 ,cry/als belong+ to ?is sy/em are d\bly refractive & biaxial1 i4e4 !y h two directions ( s+le refraction 7cf4 p4 #de74 ,! ?ree axes a1 b1 c 7,fig4 #aa7 are p>allel respectively to ! two bisectrices ( ! directions ( s+le refraction1 & ! direction p]p5dicul> to ! plane conta9+ ^? directions4 #e4 ,monocl9ic4--,su* cry/als c be ref]r$ to ?ree axes1 "o ( :i* is at "r angles to ! o!r two1 :i* are1 h[ev]1 !mselves n at "r angles4 ,spodum5e 7kunzite7 & "s moon/one cry/allize 9 ?is sy/em4 ,cry/als belong+ to ?is sy/em are d\bly refractive & biaxial1 b 9 ?is case ! fir/ axis alone is p>allel to "o ( ! pr9cipal optical directions4 #f4 ,tricl9ic4--,su* cry/als h no edges at "r angles1 & ! optical *>act]s are n imm$iately relat$ to ! cry/all9e =m4 ,"s moon/one cry/allizes 9 ?is sy/em4 ,illu/ration3 ,,fig4 #ab4--,tw9n$ ,octah$ron4 ,cry/als are (t5 n s+le sep>ate individuals4 ,= in/ance1 diamond & sp9el are f\nd 9 flat triangul> cry/als ) _! girdles cleft at ! corn]s 7,fig4 #ab74 ,ea* ( su* cry/als is really compos$ ( portions ( two simil> octah$ra1 :i* are plac$ toge!r 9 su* a way t ea* is a reflection ( ! o!r4 ,su* composite cry/als are call$ tw9s or macles4 ,sometimes ! tw9n+ is repeat$1 & ! individuals may be s m9ute z to call = a microscope = _! p]ception4 ,a composite /ructure may also result f ! conjunction ( numb]less m9ute individuals )\t any def9ite ori5tation1 z 9 ! case ( *alc$ony & agate4 ,s by suppos+ ! individuals to become inf9itesimally small1 we pass to a glass-l sub/ance4 ,x is (t5 a peculi>ity ( cry/als ( a species to display a typical comb9ation ( natural faces4 ,su* a comb9ation is kn[n z ! habit ( ! species1 & is (t5 ( s]vice = ! purpose ( id5tify+ /ones be=e !y are cut4 ,?us1 a habit ( diamond & sp9el is an octah$ron1 (t5 tw9n$1 ( g>net a dodecah$ron1 ( em]ald a flat-end$ hexagonal prism1 & s on4 ,x is "o ( ! mo/ int]e/+ & rem>kable features connect$ ) cry/allization t ! composition & ! physical *>act]s--= in/ance1 ! refractive indices & specific gravity--may1 )\t any s]i\s di/urbance ( ! molecul> arrangem5t1 v>y consid]ably ow+ to ! m or less complete replacem5t ( "o elem5t by ano!r closely alli$ to x4 ,t is ! cause ( ! range ( ! physical *>act]s :i* has be5 obs]v$ 9 su* species z t\rmal9e1 p]idot1 sp9el1 etc4 ,! pr9cipal replacem5ts 9 ! case ( ! gem-/ones are f]ric oxide1 ,fe#b,o#c1 by alum9a1 ,al#b,o#c1 & f]r\s oxide1 ,fe,o1 by magnesia1 ,mg,o4 ,a li/ ( ! pr9cipal gem-/ones1 arrang$ by _! *emical composition1 is giv5 9 ,table ,i at ! end ( ! book4 ,,*apt] ,,iii ,,reflection1 ,,refraction1 ,,& ,,disp]sion ,x is obvi\s t1 s9ce a /one suitable = ornam5tal use mu/ appeal to ! eye1 its mo/ important *>act]s are ^? :i* dep5d ^u light2 inde$1 ! :ole art ( ! lapid>y consi/s 9 %ap+ x 9 su* a way z to %[ ^! qualities to ! be/ advantage4 ,to und]/& :y c]ta9 =ms are giv5 to a cut /one1 x is ess5tial = u to asc]ta9 :at becomes ( ! light :i* falls ^u ! surface ( ! /one2 fur!r1 we %all f9d t ! action ( a /one ^u light is ( v great help 9 di/+ui%+ ! diff]5t species ( gem-/ones4 ,! ph5om5a display$ by light :i* imp+es ^u ! surface sep>at+ two m$ia#a are v simil> 9 "*1 :atev] be ! nature ( ! m$ia4 ,ord9>y exp]i5ce ) a plane mirror tells u t1 :5 light is return$1 or reflect$1 z x is usually t]m$1 f a plane or flat surface1 !re is no alt]ation 9 ! size ( objects view$ 9 ?is way1 b t ! "r & ! left h&s are int]*ang$3 our "r h& becomes ! left h& 9 our reflection 9 ! mirror4 ,we notice1 fur!r1 t our reflection is app>5tly j z f> di/ant f ! mirror on ! f>!r side z we are on ?is side4 ,9 ,fig4 #ac ,,mm is a section ( ! mirror1 & ,o is ! image ( ! h& ,o z se5 9 ! mirror4 ,light f ,o rea*es ! eye ,e by way ( m1 b x appe>s to come f ,o4 ,s9ce ,,oo is p]p5dicul> to ! mirror1 & ,o & ,o lie at equal di/ances f x1 x foll[s f elem5t>y geometry t ! angle i1 :i* ! reflect$ ray makes ) mn1 ! normal to ! mirror1 is equal to i1 ! angle :i* ! incid5t ray makes ) ! same direction4 ,illu/ration3 ,,fig4 #ac4--,reflection at a ,plane ,mirror4 ,aga91 ev]yday exp]i5ce tells u t ! case is less simple :5 light actually crosses ! b\nd+ surface & passes into ! o!r m$ium4 ,?us1 if we look d[n into a ba? fill$ ) wat]1 ! bottom ( ! ba? appe>s to h be5 rais$ up1 & a /ick plung$ into ! wat] seems to be b5t j at ! surface1 except 9 ! p>ticul> case :5 x is p]fectly upright4 ,s9ce ! /ick itself has n be5 b5t1 light evid5tly suff]s "s *ange 9 direction z x passes into ! wat] or em]ges !refrom4 ,! passage ( light f "o m$ium to ano!r 0 /udi$ by ,snell 9 ! sev5te5? c5tury1 & he enunciat$ ! foll[+ laws3-- #a4 ,! refract$ ray lies 9 ! plane conta9+ ! incid5t ray & ! normal to ! plane surface sep>at+ ! two m$ia4 ,x w be notic$ t ! reflect$ ray obeys ?is law also4 #b4 ,! angle r1 :i* ! refract$ ray makes ) ! normal1 is relat$ to ! angle i1 :i* ! incid5t ray makes ) ! same direction1 by ! equation n s9 i n s9 r1 7a7 :]e n & n are con/ants = ! two m$ia :i* are kn[n z ! indices ( refraction1 or ! refractive indices4 ,?is simple trigonometrical relation may be express$ 9 geometrical language4 ,suppose we cut a plane section ?r\gh ! two m$ia at "r angles to ! b\nd+ plane1 :i* !n appe>s z a /raight l9e1 ,,sos 7,fig4 #ad71 & suppose t ,,io repres5ts ! direction ( ! incid5t ray2 !n ,snell's fir/ law tells u t ! refract$ ray ,,or w also lie 9 ?is plane4 ,draw ! normal ,,non1 & ) c5tre ,o & any radius describe a circle int]sect+ ! incid5t & refract$ rays 9 ! po9ts a & b respectively2 let drop p]p5dicul>s ac & bd on to ! normal ,,non4 ,!n we h n4ac n4bd1 :5ce we see t if n be great] ?an n1 ac is less ?an bd1 & !re=e :5 light passes f "o m$ium into ano!r :i* is less optically d5se1 9 its passage across ! b\nd>y x is b5t1 or refract$1 away f ! normal4 ,illu/ration3 ,,fig4 #ad4--,refraction across a ,plane ,surface4 ,we see1 !n1 t :5 light falls on ! b\nd>y ( two diff]5t m$ia1 "s is reflect$ 9 ! fir/ & "s is refract$ into ! second m$ium4 ,! relative am\nts ( light reflect$ & refract$ dep5d on ! angle ( incid5ce & ! refractive indices ( ! m$ia4 ,we %all return to ?is po9t :5 we come to consid] ! lu/re ( /ones4 ,we w proce$ to consid] ! c\rse ( rays at diff]5t angles ( incid5ce :5 light passes out f a m$ium into "o less d5se--= in/ance1 f wat] into air4 ,correspond+ to light ) a small angle ( incid5ce su* z ,i#a,o 7,fig4 #ae71 "s ( x is reflect$ 9 ! direction ,,oi#a & ! rema9d] is refract$ out 9 ! direction ,,or#a4 ,simil>ly1 = ! ray ,i#b,o "s is reflect$ along ,,oi#b & "s refract$ along ,,or#b4 ,s9ce1 9 ! case we h tak51 ! angle ( refraction is great] ?an ! angle ( incid5ce1 ! refract$ ray correspond+ to "s incid5t1 ray ,ic,o w graze ! b\nd+ surface1 & correspond+ to a ray beyond x1 su* z ,i#c,o1 :i* has a /ill great] angle ( incid5ce1 !re is no refract$ ray1 & all ! light is :olly or totally reflect$ )9 ! d5se m$ium4 ,! critical angle ,ic,,on1 :i* is call$ ! angle ( total-reflection1 is v simply relat$ to ! refractive indices ( ! two m$ia2 =1 s9ce r is n[ a "r angle1 s9 r #a1 & equation 7a7 becomes n s9 i n 7b7 ,h5ce1 if ! angle ( total-reflection is measur$ & "o ( ! indices is kn[n1 ! o!r c easily be calculat$4 ,illu/ration3 ,,fig4 #ae4--,total-,reflection4 ,! ph5om5on ( total-reflection may be appreciat$ if we hold a glass ( wat] above our head1 & view ! light ( a lamp on a table reflect$ f ! "u surface ( ! wat]4 ,?is reflection is incomp>ably m brilliant ?an t giv5 by ! upp] surface4 ,! refractive index ( air is tak5 z unity2 /rictly1 x is t ( a vacuum1 b ! diff]5ce is too small to be appreciat$ ev5 9 v delicate "w4 ,e sub/ance has diff]5t indices = light ( diff]5t col\r1 & x is cu/om>y to take z ! /&>d ! yell[ light ( a sodium flame4 ,?is happ5s to be ! col\r to :i* our eyes are mo/ s5sitive1 & a flame ( ?is k9d is easily prep>$ by volatiliz+ a little bic>bonate ( soda 9 ! flame ( a buns5 burn]4 ,a survey ( ,table ,,iii at ! end ( ! book %[s cle>ly h[ valuable a measurem5t ( ! refractive index is = det]m9+ ! species to :i* a cut /one belongs4 ,! values f\nd = diff]5t specim5s ( ! species d 9 cases v>y consid]ably ow+ to ! great latitude possible 9 ! *emical con/itution due to ! isomorph\s replacem5t ( "o elem5t by ano!r4 ,"s v>iation 9 ! index may ev5 occur 9 diff]5t directions )9 ! same /one2 x results f ! rem>kable prop]ty ( splitt+ up a beam ( light into two beams1 :i* is possess$ by _m cry/alliz$ sub/ances4 ,?is =ms ! subject ( a lat] *apt]4 ,^u ! fact t ! refractive index ( a sub/ance v>ies = light ( diff]5t col\rs dep5ds su* famili> ph5om5a z ! spl5d\r ( ! ra9b[ & ! #8fire' ( ! diamond4 ,:5 :ite light is refract$ into a /one x no long] rema9s :ite1 b is split up into a spectrum4 ,except 9 c]ta9 anomal\s sub/ances ! refractive index increases progressively z ! wave-l5g? ( ! light decreases1 & consequ5tly a normal spectrum is violet at "o end & passes ?r\gh gre5 & yell[ to r$ at ! o!r end4 ,! wid? ( ! spectrum1 :i* may be measur$ by ! diff]5ce betwe5 ! refractive indices = ! extreme r$ & violet rays1 also v>ies1 ?\gh on ! :ole x increases ) ! refractive index4 ,x is ! disp]sion1 z ?is diff]5ce is t]m$1 t det]m9es ! #8fire'--a "* ( ! utmo/ importance 9 col\rless transp>5t /ones1 :i*1 b = x1 w\ld be lack+ 9 int]e/4 ,diamond excels all col\rless /ones 9 ?is respect1 al?\gh x is closely foll[$ by zircon1 ! col\r ( :i* has be5 driv5 (f by heat+2 x is1 h[ev]1 surpass$ by two col\r$ species3 sph5e1 :i* is seldom se5 9 jewell]y1 & demantoid1 ! gre5 g>net f ! ,urals1 :i* (t5 passes "u ! misnom] #8oliv9e4' ,! disp]sion ( ! m prom95t species = ! ,b & ,g l9es ( ! sol> spectrum is giv5 9 ,table ,,iv at ! end ( ! book4 ,we w n[ proce$ to discuss me?ods t may be us$ = ! measurem5t ( ! refractive indices ( cut /ones4 ,,*apt] ,,iv ,,measurem5t ,,( ,,refractive ,,indices ,! me?ods available = ! measurem5t ( refractive indices are ( two k9ds1 & make use ( two diff]5t pr9ciples4 ,! fir/1 :i* is bas$ ^u ! v simple relation f\nd 9 ! la/ *apt] to subsi/ at total-reflection1 c be us$ ) ease & cel]ity1 & is be/ suit$ = discrim9ative purposes2 b x is re/rict$ 9 its application4 ,! second1 :i* dep5ds on ! measurem5t ( ! angle betwe5 two facets & ! m9imum deviation exp]i5c$ by a ray ( light :5 trav]s+ a prism =m$ by !m1 is m involv$1 entails ! use ( m elaborate app>atus1 & takes consid]able "t1 b x is less re/rict$ 9 its application4 7#a7 ,,! ,,me?od ,,( ,,total-,,reflection ,we see f equation b 7p4 #ah71 connect+ ! angle ( total-reflection ) ! refractive indices ( ! adjac5t m$ia1 t1 if ! d5s] m$ium be con/ant1 ! indices ( all less d5se m$ia may be easily det]m9$ f a measurem5t ( ! correspond+ critical angle4 ,9 all refractomet]s ! con/ant m$ium is a glass ) a high refractive index4 ,"s in/rum5ts h rotatory p>ts1 by means ( :i* ?is angle is actually measur$4 ,su* in/rum5ts give v good results1 b suff] f ! disadvantages ( be+ nei!r portable nor conv5i5t to h&le1 & ( n giv+ a result )\t "s computation4 ,illu/ration3 ,,fig4 #af4--,refractomet] 7actual size74 ,= use 9 ! id5tification ( cut /ones1 a refractomet] ) a fix$ scale1 su* z t 7,fig4 #af7 devis$ by ! au?or1 is f> m conv5i5t4 ,9 ord] to facilitate ! obs]vations1 a totally reflect+ prism has be5 ins]t$ betwe5 ! two l5ses ( ! eyepiece4 ,! eyepiece may be adju/$ to suit ! individual eyesight2 b = obs]v]s ) exceptionally long sight an adapt] is provid$1 :i* p]mits ! eyepiece be+ drawn out to ! requisite ext5t4 ,! refractomet] mu/ be held 9 ! mann] illu/rat$ 9 ,fig4 #ag1 s t ! light f a w9d[ or o!r s\rce ( illum9ation ent]s ! in/rum5t by ! l5ticul> op5+ und]nea?4 ,good1 ev5 illum9ation ( ! field may also v simply be secur$ by reflect+ light into ! in/rum5t f a %eet ( :ite pap] laid on a table4 ,on look+ d[n ! eyepiece we see a scale 7,fig4 #ah71 ! eyepiece be+1 if necess>y1 focus$ until ! divisions ( ! scale are cle>ly & di/9ctly se54 ,suppose1 = exp]im5t1 we sme> a little vasel9e or simil> fatty sub/ance on ! plane surface ( ! d5se glass1 :i* j projects beyond ! level ( ! brass plate embrac+ x4 ,! field ( view is n[ no long] uni=mly illum9at$1 b is divid$ into two p>ts 7,fig4 #ai73 a d>k portion above1 :i* t]m9ates 9 a curv$ edge1 app>5tly gre5 9 col\r1 & a bright portion und]nea?1 :i* is compos$ ( totally reflect$ light4 ,if we tilt ! in/rum5t d[nw>ds s t light ent]s ! in/rum5t f above ?r\gh ! vasel9e we f9d t ! portions ( ! field are rev]s$1 ! d>k portion be+ und]nea? & t]m9at$ by a r$ edge4 ,x is possible s to arrange ! illum9ation t ! two portions are ev5ly light$1 & ! common edge becomes almo/ invisible4 ,x is !re=e ess5tial = obta9+ satisfactory results t ! plate & ! d5se glass be %ield$ f ! light by ! dis5gag$ h&4 ,! %ad[-edge is curv$1 & is1 inde$1 an arc ( a circle1 because sph]ical surfaces are us$ 9 ! optical arrangem5ts ( ! refractomet]2 by ! sub/itution ( cyl9drical surfaces x becomes /raight1 b suffici5t advantage is n secur$ !reby to comp5sate = ! greatly increas$ complexity ( ! con/ruction4 ,! %ad[-edge is col\r$1 because ! relative disp]sion1 nv nr ------------------------------ 7nv & nr be+ ! refractive indices = n ! extreme violet & r$ rays respectively71 ( ! vasel9e diff]s f t ( ! d5se glass4 ,! disp]sion ( ! glass is v high1 & exce$s t ( any /one = :i* x c be us$4 ,c]ta9 oils h1 h[ev]1 ne>ly ! same relative disp]sion1 & ! edges correspond+ to !m are consequ5tly almo/ col\rless4 ,a c>eful eye w p]ceive t ! col\r$ %ad[-edge is 9 reality a spectrum1 ( :i* ! violet end lies 9 ! d>k portion ( ! field & ! r$ edge m]ges into ! bright portion4 ,! yell[ col\r ( a sodium flame1 :i*1 z has already be5 /at$1 is select$ z ! /&>d = ! measurem5t ( refractive indices1 lies betwe5 ! gre5 & ! r$1 & ! "p ( ! spectrum to be not$ is at ! bottom ( ! gre51 & practically1 !re=e1 at ! bottom ( ! %ad[1 because ! yell[ & r$ are almo/ lo/ 9 ! brightness ( ! l[] portion ( ! field4 ,if a sodium flame be us$ z ! s\rce ( illum9ation1 ! %ad[-edge becomes a %>ply def9$ l9e4 ,! scale is s graduat$ & arrang$ t ! read+ :]e ?is l9e crosses ! scale gives ! correspond+ refractive index1 ! read+1 s9ce ! l9e is curv$1 be+ tak5 9 ! middle ( ! field on ! "r-h& side ( ! scale4 ,! refractomet] !re=e gives at once1 )\t any int]m$iate calculation1 a value ( ! refractive index to ! second place ( decimals1 & a skill$ obs]v] may1 by e/imat+ ! t5?s ( ! int]vals betwe5 successive divisions1 arrive at ! ?ird place2 to facilitate ?is e/imation ! semi-divisions beyond #afej h be5 ins]t$4 ,! range ext5ds ne>ly to #ahjj2 = any sub/ance ) a high] refractive index ! field is d>k z f> z ! limit at ! bottom4 ,illu/ration3 ,,fig4 #ag4--,me?od ( ,us+ ! ,refractomet]4 ,illu/ration3 ,,fig4 #ah4--,scale ( ! ,refractomet]4 ,illu/ration3 ,,fig4 #ai4--,%ad[-edge giv5 by a s+ly refractive ,sub/ance4 ,a fat1 or a liquid1 wets ! glass1 i4e4 comes into intimate contact ) x1 b if a solid sub/ance be te/$ 9 ! same way1 a film ( air w\ld int]v5e & entirely prev5t an obs]vation4 ,to displace x1 a drop ( "s liquid :i* is m highly refractive ?an ! sub/ance "u te/ mu/ fir/ be appli$ to ! plane surface ( ! d5se glass4 ,! mo/ conv5i5t liquid = ! purpose is me?yl5e iodide1 ,,*#b;,i#b1 :i*1 :5 pure1 has at ord9>y room temp]atures a refractive index ( #agdb4 ,x is almo/ col\rless :5 fre%1 b turns r$di% br[n on exposure to light4 ,if desir$1 x may be cle>$ 9 ! mann] describ$ bel[ 7p4 #ff71 b ! film ( liquid actually us$ is s ?9 t ?is precaution is sc>cely necess>y4 ,if we te/ a piece ( ord9>y glass--"o ( ! slips us$ by microscopi/s = cov]+ ?9 sections is v conv5i5t = ! purpose--fir/ apply+ a drop ( me?yl5e iodide to ! plane surface ( ! d5se glass ( ! refractomet] 7,fig4 #bj71 we notice a col\r$ %ad[-edge correspond+ to ! glass-slip at ab\t #aecj & ano!r1 almo/ col\rless1 at #agdb1 :i* corresponds to ! liquid4 ,if ! solid sub/ance :i* is te/$ is m highly refractive ?an me?yl5e iodide1 only ! latt] ( ! %ad[-edges is visible1 & we mu/ utilize "s m refractive liquid4 ,we c1 h[ev]1 raise ! refractive index ( me?yl5e iodide by dissolv+ sulphur#b 9 x2 ! refractive index ( ! saturat$ liquid lies well beyond #ahjj & ! %ad[-edge correspond+ to x1 !re=e1 does n come )9 ! range ( ! refractomet]4 ,! pure & ! saturat$ liquids c be procur$ ) ! in/rum5t1 ! bottles conta9+ !m be+ japann$ on ! outside to exclude light & fitt$ ) dipp+-/opp]s1 by means ( :i* a drop ( ! liquid requir$ is easily transf]r$ to ! surface ( ! glass ( ! in/rum5t4 ,s long z ! liquid is m highly refractive ?an ! /one1 or :atev] may be ! sub/ance "u exam9ation1 its precise refractive index is ( no consequ5ce4 ,! facet us$ 9 ! te/ mu/ be flat1 & mu/ be press$ firmly on ! in/rum5t1 s t x is truly p>allel to ! plane surface ( ! d5se glass2 = good results1 moreov]1 x mu/ be bright4 ,illu/ration3 ,,fig4 #bj4--;,facet$ ,/one 9 ,position on ! ,refractomet]4 ,illu/ration3 ,,fig4 #ba4--,%ad[-edges giv5 by a d\bly refractive sub/ance4 ,we h s f> assum$ t ! sub/ance :i* we are te/+ is simple & gives a s+le %ad[-edge2 b1 z may be se5 f ,table ,v1 _m ( ! gem-/ones are d\bly refractive1 & su* w1 9 g5]al1 %[ 9 ! field ( ! refractomet] two di/9ct %ad[-edges m or less widely sep>at$4 ,suppose1 = example1 we /udy ! effect produc$ by a p]idot1 :i* displays ! ph5om5on to a m>k$ degree4 ,if we revolve ! /one s t ! facet "u obs]vation rema9s p>allel to ! plane surface ( ! d5se glass ( ! refractomet] & 9 contact ) x1 we notice t bo? ! %ad[-edges 9 g5]al move up or d[n ! scale4 ,9 p>ticul> cases1 dep5d+ ^u ! relation ( ! position ( ! facet select$ to ! cry/all9e symmetry1 "o or bo? ( !m may rema9 fix$1 or "o may ev5 move across ! o!r4 ,b :atev] facet ( ! /one be us$ = ! te/1 & h[ev] v>iable be ! movem5ts ( ! %ad[-edges1 ! highe/ & l[e/ read+s obta9able rema9 ! same2 !y are ! pr9cipal indices ( refraction1 su* z are /at$ 9 ,table ,,iii at ! end ( ! book1 & _! diff]5ce measures ! maximum am\nt ( d\ble refraction possess$ by ! /one4 ,! proc$ure is !re=e simplicity itself2 we h m]ely to revolve ! /one on ! in/rum5t1 usually ?r\gh n m ?an a "r angle1 & note ! greate/ & lea/ read+s4 ,x w be notic$ t ! %ad[-edges cross ! scale symmetrically 9 ! critical & skewwise 9 int]m$iate positions4 ,fig4 #ba repres5ts ! effect :5 ! facet is su* z to give simultane\sly ! two read+s requir$4 ,! %ad[-edges a & b1 :i* are col\r$ 9 :ite light1 correspond to ! lea/ & greate/ respectively ( ! pr9cipal refractive indices1 :ile ! ?ird %ad[-edge1 :i* is v fa9t1 corresponds to ! liquid us$--me?yl5e iodide4 ,x is possible1 z we %all see 9 a lat] *apt]1 to le>n f ! motion1 if any1 ( ! %ad[-edges some?+ z to ! "* ( ! d\ble refraction4 ,s9ce1 h[ev]1 ea* %ad[-edge is spectral 9 :ite light1 !y w n be di/9ctly sep>ate unless ! d\ble refraction exce$s ! relative disp]sion4 ,topaz1 = in/ance1 appe>s 9 :ite light to yield only a s+le %ad[-edge1 & may ?us easily be di/+ui%$ f t\rmal9e1 9 :i* ! d\ble refraction is l>ge en\gh = ! sep>ation ( ! two %ad[-edges to be cle>ly disc]n$4 ,9 sodium light1 h[ev]1 no difficulty is exp]i5c$ 9 di/+ui%+ bo? ! %ad[-edges giv5 by sub/ances ) small am\nt ( d\ble refraction1 su* z *rysob]yl1 qu>tz1 & topaz1 & a skill$ obs]v] may detect ! sep>ation 9 ! extreme in/ances ( apatite1 idocrase1 & b]yl4 ,! %ad[-edge correspond+ to ! great] refractive index is always less di/9ct1 because x lies 9 ! bright portion ( ! field4 ,if ! /one or its facet be small1 x mu/ be mov$ on ! plane surface ( ! d5se glass until ! greate/ possible di/9ctness is imp>t$ to ! edge or edges4 ,if x be mov$ t[>ds ! obs]v] f ! fur!r end1 a mi/y %ad[ appe>s to move d[n ! scale until ! correct position is rea*$1 :5 ! edges spr+ into view4 ,any facet ( a /one may be utiliz$ s long z x is flat1 b ! table-facet is ! mo/ conv5i5t1 because x is usually ! l>ge/1 & x is available ev5 :5 ! /one is m\nt$4 ,t ! /one ne$ n be remov$ f its sett+ is "o ( ! great advantages ( ?is me?od4 ,! small] ! /one ! m difficult x is to manipulate2 caution especially mu/ be ex]cis$ t x be n tilt$1 n only because ! %ad[-edge w\ld be %ift$ f its true position & an errone\s value ( ! refractive index obta9$1 b also because a corn] or edge ( ! /one w\ld inevitably scrat* ! glass ( ! in/rum5t1 :i* is f> s(t] ?an ! h>d gem-/ones4 ,me?yl5e iodide w 9 "t attack & /a9 ! glass1 & mu/ !re=e be wip$ (f ! in/rum5t imm$iately aft] use4 7#b7 ,,! ,,me?od ,,( ,,m9imum ,,deviation ,if ! /one be too highly refractive = a measurem5t ( its refractive index to be possible ) ! refractomet] j describ$1 & x is desir$ to det]m9e ?is con/ant1 rec\rse mu/ be _h to ! prismatic me?od1 = :i* purpose an in/rum5t kn[n z a goniomet]#c is requir$4 ,two angles mu/ be measur$2 "o ! int]ior angle includ$ betwe5 a suitable pair ( facets1 & ! o!r ! m9imum am\nt ( ! deviation produc$ by ! pair ^u a beam ( light trav]s+ !m4 ,illu/ration3 ,,fig4 #bb4--,pa? at ,m9imum ,deviation ( a ,ray trav]s+ a ,prism =m$ ( two ,facets ( a ,cut ,/one4 ,fig4 #bb repres5ts a section ( a /ep-cut /one p]p5dicul> to a s]ies ( facets ) p>allel edges2 t is ! table1 & a1 b1 c1 are facets on ! culet side4 ,! pa? ( light trav]s+ ! prism =m$ by ! pair ( facets1 t & b1 is indicat$4 ,suppose t ,a is ! int]ior angle ( ! prism1 i ! angle ( incid5ce ( light at ! fir/ facet & i ! angle ( em]g5ce at ! second facet1 & r & r ! angles inside ! /one at ! two facets respectively4 ,!n at ! fir/ facet light has be5 b5t ?r\gh an angle i - r1 & aga9 at ! second facet ?r\gh an angle i - r2 ! angle ( deviation1 ,d1 is !re=e giv5 by ,d i i - 7r r74 ,we h fur!r t r r ,a1 :5ce x foll[s t ,a ,d i i4 ,if ! /one be m\nt$ on ! goniomet] & adju/$ s t ! edge ( ! prism is p>allel to ! axis ( rotation ( ! in/rum5t & if light f ! collimator fall ^u ! table-facet & ! telescope be turn$ to ! prop] position to receive ! em]g5t beam1 a spectral image ( ! object-slit1 or 9 ! case ( a d\bly refractive /one 9 g5]al1 two spectral images1 w be se5 9 :ite light2 9 ! light ( a sodium flame ! images w be %>p & di/9ct4 ,suppose t we rotate ! /one 9 ! direction ( dim9i%+ deviation & simultane\sly ! telescope s z to reta9 an image 9 ! field ( view1 we f9d t ! image moves up to & !n away f a c]ta9 position1 at :i*1 !re=e1 ! deviation is a m9imum4 ,! image moves 9 ! same direction f ?is position :i*ev] way ! /one be rotat$4 ,! "q !n arises :at are ! angles ( incid5ce & refraction "u ^! special conditions4 ,x is cle> t a pa? ( light is rev]sible2 t is to say1 if a beam ( light trav]ses ! prism f ! facet t to ! facet b x c take precisely ! same pa? f ! facet b to ! facet t4 ,h5ce we %\ld be l$ to expect t1 s9ce exp]im5t tea*es u t !re is only "o position ( m9imum deviation correspond+ to ! same pair ( facets1 ! angles at ! two facets mu/ be equal1 i4e4 i i1 & r r4 ,x is1 inde$1 n difficult to prove by ei!r geometrical or analytical me?ods t su* is ! case4 ,a ,a ,d ,!re=e at m9imum deviation r ------ & i ------------------1 &1 #b #b s9ce s9 i n s9 r1 :]e n is ! refractive index ( ! /one1 we h ! simple relation-- ,a ,d s9 ------------------ #b n -------------------------- ,a s9 ------ #b ,?is relation is /rictly true only :5 ! direction ( m9imum deviation is "o ( cry/all9e symmetry 9 ! /one1 & holds !re=e 9 g5]al = all s+ly refractive /ones1 & = ! ord9>y ray ( a uniaxial /one2 b ! values ?us obta9$ ev5 9 ! case ( biaxial /ones are approximate en\gh = discrim9ative purposes4 ,if !n ! /one be s+ly refractive1 ! result is ! index requir$2 if x be uniaxial1 "o value is ! ord9>y index & ! o!r image gives a value ly+ betwe5 ! ord9>y & ! extraord9>y indices2 if x be biaxial1 ! values giv5 by ! two images may lie any:]e betwe5 ! greate/ & ! lea/ refractive indices4 ,! angle ,a mu/ n be too l>ge2 o!rwise ! light w n em]ge at ! second facet1 b w be totally reflect$ inside ! /one3 on ! o!r h&1 x mu/ n be too small1 because any error 9 its det]m9ation w\ld !n s]i\sly affect ! accuracy ( ! value d]iv$ = ! refractive index4 ,al?\gh ! mono*romatic light ( a sodium flame is ess5tial = precise "w1 a suffici5tly approximate value = discrim9ative purposes is obta9$ by not+ ! position ( ! yell[ portion ( ! spectral image giv5 9 :ite light4 ,9 ! case ( a /one su* z t depict$ 9 ,fig4 #bb images are giv5 by o!r pairs ( facets1 = in/ance ta & tc1 unless ! angle includ$ by ! =m] is too l>ge4 ,!re might !re=e be "s d\bt1 to :i* pair "s p>ticul> image correspond$2 b no confusion c arise if ! foll[+ proc$ure be adopt$4 ,illu/ration3 ,,fig4 #bc4--;,c\rse ( ,obs]vations 9 ! ,me?od ( ,m9imum ,deviation4 ,! table1 or "s easily recognizable facet1 is select$ z ! facet at :i* light ent]s ! /one4 ,! telescope is fir/ plac$ 9 ! position 9 :i* x is directly opposite ! collimator 7,t#j 9 ,fig4 #bc71 & clamp$4 ,! scale is turn$ until x reads exactly z]o1 #j or #cfj1 & clamp$4 ,! telescope is releas$ & revolv$ 9 ! direction ( increas+ read+s ( ! scale to ! position ( m9imum deviation1 ,t4 ,! read+ ( ! scale gives at once ! angle ( m9imum deviation1 ,d4 ,! hold] c>ry+ ! /one is n[ clamp$ to ! scale1 & ! telescope is turn$ to ! position1 ,t#a1;9 :i* ! image giv5 by reflection f ! table facet is 9 ! c5tre ( ! field ( view2 ! read+ ( ! scale is tak54 ,! telescope is clamp$1 & ! scale is releas$ & rotat$ until x reads ! angle already f\nd = ,d4 ,if no mi/ake has be5 made1 ! reflect$ image f ! second facet is n[ 9 ! field ( view4 ,x w probably n be q c5tral1 z !oretically x %\ld be1 because ! /one may n h be5 orig9ally q 9 ! position ( m9imum deviation1 a comp>atively l>ge rotation ( ! /one produc+ no app>5t *ange 9 ! position ( ! refract$ image at m9imum deviation1 & fur!r1 because1 z has already be5 /at$1 ! me?od is n /rictly true = biaxial /ones4 ,! diff]5ce 9 read+s1 h[ev]1 %\ld n exce$ #b4 ,! read+1 ,s1 ( ! scale is n[ tak51 & x toge!r ) #ahj subtract$ f ! read+ = ! fir/ facet1 & ! value ( ,a1 ! int]ior angle betwe5 ! two facets1 obta9$4 ,let u take an example4 ,read+ ,t 7 ,d7 #dj #da ,read+ ,t#a #bfa #ce less #ahj #ahj #j -------------- #ha #ce ,read+ ,s #da #cj -------------- ,d #bj #bj ,a #dj #e ,a #bj #b ,a #bj #b -------------- 7,a ,d7 #dj #bc ,log s9 #dj #bc #i4haaea ,log s9 #bj #b #i4ecdib -------------- ,log n #j4bgfei n #a4hijf4 ,! read+s ,s & ,t are v ne>ly ! same1 & !re=e we may be sure t no mi/ake has be5 made 9 ! selection ( ! facets4 ,9 place ( log>i?m-tables we may make use ( ! diagram on ,plate ,,ii4 ,! radial l9es correspond to ! angles ( m9imum deviation & ! skew l9es to ! prism angles1 & ! di/ance along ! radial l9es gives ! refractive index4 ,we run our eye along ! l9e = ! obs]v$ angle ( m9imum deviation & note :]e x meets ! curve = ! obs]v$ prism angle2 ! refractive index correspond+ to ! po9t ( int]section is at once read (f4 ,?is me?od has sev]al obvi\s disadvantages3 x requires ! use ( an exp5sive & elaborate in/rum5t1 an obs]vation takes consid]able "t1 & ! values ( ! pr9cipal refractive indices _c 9 g5]al be imm$iately det]m9$4 ,table ,,iii at ! end ( ! book gives ! refractive indices ( ! gem-/ones4 ,illu/ration3 ,,plate ,,ii ,,refractive ,,index ,,diagram ,,*apt] ,v ,,lu/re ,,& ,,%e5 ,x has be5 already /at$ t :5ev] light 9 "o m$ium falls ^u ! surface sep>at+ x f ano!r m$ium "s ( ! light is reflect$ )9 ! fir/1 :ile ! rema9d] passes out into ! second m$ium1 except :5 ! fir/ is ( l[] refractivity ?an ! second & light falls at an angle great] ?an t ( total-reflection4 ,simil>ly1 :5 light imp+es ^u a cut /one "s ( x is reflect$ & ! rema9d] passes into ! /one4 ,:at is ! relative am\nt ( reflect$ light dep5ds ^u ! nature ( ! /one--its refractivity & h>dness--& det]m9es its lu/re2 ! great] ! am\nt ! m lu/r\s w ! /one appe>4 ,!re are diff]5t k9ds ( lu/re1 & ! int5sity ( ea* dep5ds on ! poli% ( ! surface4 ,f a dull1 i4e4 an unev51 surface ! reflect$ light is scatt]$1 & !re are no brilliant reflections4 ,all gem-/ones take a good poli%1 & h !re=e1 s long z ! surface reta9s its poli%1 consid]able brilliancy2 turquoise1 on acc\nt ( its s(tness1 is always comp>atively dull4 ,! diff]5t k9ds ( lu/re are-- 7#a7 ,adamant9e1 *>act]i/ic ( diamond4 7#b7 ,vitre\s1 z se5 on ! surface ( fractur$ glass4 7#c7 ,res9\s1 z %[n by res9s4 ,zircon & demantoid1 ! gre5 g>net call$ by jewell]s 8oliv9e10 alone among gem-/ones h a lu/re approa*+ t ( diamond4 ,! rema9d] all h a vitre\s lu/re1 ?\gh v>y+ 9 degree1 ! h>d] & ! m refractive species be+ on ! :ole ! m lu/r\s4 ,"s /ones--= in/ance1 a c9namon g>net--appe> to h a c]ta9 greas9ess 9 ! lu/re1 :i* is caus$ by /ray reflections f inclusions or o!r breaks 9 ! homog5eity ( ! int]ior4 ,a pe>ly lu/re1 :i* arises f cleavage cracks & is typically display$ by ! cleavage face ( topaz1 w\ld be se5 9 a cut /one only :5 flaw$4 ,c]ta9 corundums :5 view$ 9 ! direction ( ! cry/allographical axis display six n>r[ l9es ( light radiat+ at angles ( #fj f a c5tre 9 a mann] sugge/ive ( ! conv5tional repres5tations ( />s4 ,su* /ones are consequ5tly kn[n z a/]ias1 or m usually />-/ones--/>-rubies or />-sapphires1 z ! case may be1 & ! ph5om5on is call$ a/]ism4 ,^! /ones h n a homog5e\s /ructure1 b conta9 tube-l cavities regul>ly arrang$ at angles ( #fj 9 planes at "r angles to ! cry/allographical axis4 ,! effect is be/ produc$ :5 ! /ones are cut en cabo*on p]p5dicul> to t axis4 ,*atoyancy is a some:at simil> ph5om5on1 b 9 ?is case ! fibres or cavities are p>allel to a s+le direction1 & a s+le broadi% b& is display$ at "r angles to x4 ,cat's-eyes1 z ^! /ones are t]m$1 are cut en cabo*on p>allel to ! fibres4 ,! true cat's-eye 7,plate ,,xxix1 ,fig4 #a7 is a v>iety ( *rysob]yl1 b ! t]m is also (t5 appli$ to qu>tz %[+ a simil> appe>ance4 ,! latt] is really a fibr\s m9]al1 su* z asbe/os1 :i* has become conv]t$ into silica4 ,! beautiful tig]'s-eye f ,s\? ,africa is a silicifi$ crocidolite1 ! orig9al blue col\r ( :i* has be5 alt]$ by oxidation to gold5 br[n4 ,rec5tly t\rmal9es h be5 discov]$ :i* are suffici5tly fibr\s 9 /ructure to display an effective *atoyancy4 ,! milky %e5 ( moon/one 7,plate ,,xxix1 ,fig4 #d7 owes its effect to reflections f tw9 lamell4 ,! wond]ful iridesc5ce :i* is ! glory ( opal1 & is !re=e t]m$ opalesc5ce1 arises f a /ructure :i* is peculi> to t species4 ,opal is a solidifi$ jelly2 on cool+ x has become riddl$ ) extremely ?9 cracks1 :i* 7 subsequ5tly fill$ ) simil> mat]ial ( slightly diff]5t refractivity1 & ?us x consi/s ( a s]ies ( films4 ,at ! surface ( ea* film int]f]5ce ( light takes place j z at ! surface ( a soap-bubble1 & ! m ev5ly ! films are spac$ ap>t ! m uni=m is ! col\r display$1 ! actual t9t dep5d+ ^u ! ?ickness ( ! films trav]s$ by ! light giv+ rise to ! ph5om5on4 ,,*apt] ,,vi ,,d\ble ,,refraction ,! optical ph5om5on pres5t$ by _m gem-/ones is complicat$ by _! prop]ty ( splitt+ up a beam ( light into two )1 9 g5]al1 diff]+ *>act]s4 ,9 ?is *apt] we %all discuss ! nature ( d\ble refraction1 z x is t]m$1 & me?ods = its detection4 ,! ph5om5on is n "o t comes )9 ! purview ( ev]yday exp]i5ce4 ,s long ago z #affi a ,dani% physician1 by "n ,b>?ol9us1 notic$ t a plate ( ! transp>5t m9]al :i* at t "t _h rec5tly be5 br\ght ov] f ,icel&1 & 0 !re=e call$ 8,icel&-sp>10 possess$ ! rem>kable prop]ty ( giv+ a d\ble image ( objects close to x :5 view$ ?r\gh x4 ,subsequ5t inve/igation has %[n t mu* cry/alliz$ matt] is d\bly refractive1 b 9 calcite--to use ! sci5tific "n = ! species :i* includes ,icel&-sp>--alone among common m9]als is ! ph5om5on s conspicu\s z to be obvi\s to ! unaid$ eye4 ,! app>5t sep>ation ( ! pair ( images giv5 by a plate cut or cleav$ 9 any direction dep5ds ^u its ?ickness4 ,! l>ge mass1 upw>ds ( two feet 7#fj cm47 9 ?ickness1 :i* is exhibit$ at ! f> end ( ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory71 displays ! sep>ation to a degree t is probably unique4 ,illu/ration3 ,,fig4 #bd4--;,app>5t d\bl+ ( ! ,edges ( a ,p]idot :5 view$ ?r\gh ! ,table-,facet4 ,al?\gh none ( ! gem-/ones c emulate calcite 9 ?is "*1 yet ! d\ble refraction ( c]ta9 ( !m is l>ge en\gh to be detect$ )\t mu* difficulty4 ,9 ! case ( facet$ /ones ! opposite edges %\ld be view$ ?r\gh ! table-facet1 & any signs ( d\bl+ not$4 ,! d\ble refraction ( sph5e is s l>ge1 viz4 #jjh1 t ! d\bl+ ( ! edges is evid5t to ! unaid$ eye4 ,9 p]idot 7,fig4 #bd71 zircon 7b71 & epidote ! app>5t sep>ation ( ! edges is easily disc]n$ ) ! assi/ance ( an ord9>y l5s4 ,a ke5 eye c detect ! ph5om5on ev5 9 ! case ( su* sub/ances z qu>tz ) small d\ble refraction4 ,x mu/1 h[ev]1 be rememb]$ t 9 all su* /ones ! refraction is s+le 9 c]ta9 directions1 & ! am\nt ( d\ble refraction v>ies !re=e ) ! direction f nil to ! maximum possess$ by ! /one4 ,exp]im5t ) a plate ( ,icel&-sp> %[s t ! rays transmitt$ by x h prop]ties diff]+ f ^? ( ord9>y light4 ,on sup]pos+ a second plate we notice t !re are n[ two pairs ( images1 :i* are 9 g5]al no long] ( equal brightness1 z 0 ! case be=e4 ,if ! second plate be rotat$ ) respect to ! fir/1 two images1 "o ( ea* pair1 disappe>1 & !n ! o!r two1 ! plate hav+ turn$ ?r\gh a "r angle betwe5 ! two positions ( ext9ction2 midway betwe5 ^! positions ! images are all equally bright4 ,?is v>iation ( int5sity implies t ea* ( ! rays em]g+ f ! fir/ plate has acquir$ a "o-sid$ "*1 or1 z x is usually express$1 has become plane-pol>iz$1 or1 %ortly1 pol>iz$4 ,illu/ration3 ,,fig4 #be4--,wave-,motion4 ,be=e ! discov]y ( ! ph5om5on ( d\ble refraction ! f\ndation ( ! mod]n !ory ( light _h be5 laid by ! g5ius ( ,huyg5s4 ,accord+ to ?is !ory light is ! result ( a wave-motion 7,fig4 #be7 9 ! e!r1 a m$ium t p]vades ! :ole ( space :e!r occupi$ by matt] or n1 & transmits ! wave-motion at a rate v>y+ ) ! matt] ) :i* x happ5s to co9cide4 ,su* a m$ium has be5 assum$ because x expla9s satisfactorily all ! ph5om5a ( light1 b x by no means foll[s t x has a concrete exi/5ce4 ,inde$1 if x has1 x is s t5u\s z to be imp]ceptible to ! mo/ delicate exp]im5ts4 ,! wave-motion is simil> to t obs]v$ on ! surface ( /ill wat] :5 di/urb$ by a /one flung into x4 ,! waves spread out f ! s\rce ( di/urbance2 b1 al?\gh ! waves seem to advance1 ! actual p>ticles ( wat] m]ely move up & d[n1 & h no motion at all 9 ! direction 9 :i* ! waves are mov+4 ,if we imag9e simil> motion to take place 9 any plane & n only ! horizontal1 we =m "s idea ( ! nature ( ord9>y light4 ,b aft] pass+ ?r\gh a plate ( ,icel&-sp>1 light no long] vibrates 9 all directions1 b 9 ea* beam ! vibrations are p>allel to a p>ticul> plane1 ! two planes be+ at "r angles4 ,! exact relation ( ! direction ( ! vibrations to ! plane ( pol>ization is unc]ta91 al?\gh x und\bt$ly lies 9 ! plane conta9+ ! direction ( ! ray ( light & ! p]p5dicul> to ! plane ( pol>ization4 ,! waves = diff]5t col\rs diff] 9 _! l5g?1 i4e4 9 ! di/ance1 #b bb 7,fig4 #be71 f cre/ to cre/1 :ile ! velocity1 :i* rema9s ! same = ! same m$ium1 is proportional to ! wave-l5g?4 ,! int5sity ( ! light v>ies z ! squ>e ( ! amplitude ( ! wave1 i4e4 ! height1 ab1 ( ! cre/ f ! mean level4 ,v>i\s me?ods h be5 propos$ = obta9+ pol>iz$ light4 ,?us ,seebeck f\nd 9 #ahac t a plate ( br[n t\rmal9e cut p>allel to ! cry/allographic axis & ( suffici5t ?ickness 7cf4 p4 #aa7 transmits only "o ray1 ! o!r be+ entirely absorb$ )9 ! plate4 ,ano!r me?od 0 to employ a glass plate to reflect light at a c]ta9 critical angle4 ,! mo/ effici5t me?od1 & t 9 g5]al use at ! pres5t day1 is due to ! inv5tion ( ,nicol4 ,a rhomb ( ,icel&-sp> 7,fig4 #bf71 ( suitable l5g?1 is slic$ along ! long] diagonal1 dd1 & ! halves are cem5t$ toge!r by means ( canada balsam4 ,"o ray1 ioo1 is totally reflect$ at ! surface sep>at+ ! m9]al & ! cem5t1 & does n p5etrate into ! o!r half2 :ile ! o!r ray1 iee1 is transmitt$ ) almo/ undim9i%$ int5sity4 ,su* a rhomb is call$ a ,nicol's prism aft] its inv5tor1 or briefly1 a nicol4 ,illu/ration3 ,,fig4 #bf4--,nicol's ,prism4 ,if "o nicol be plac$ above ano!r & _! correspond+ pr9cipal planes be at "r angles no light is transmitt$ ?r\gh ! pair4 ,9 ! pol>iz+ microscope "o su* nicol1 call$ ! pol>iz]1 is plac$ bel[ ! /age1 & ! o!r1 call$ ! analys]1 is ei!r ins]t$ 9 ! body ( ! microscope or plac$ above ! eyepiece1 & ! pair are usually set 9 ! cross$ position s t ! field ( ! microscope is d>k4 ,if a piece ( glass or a fragm5t ( "s s+ly refractive sub/ance be plac$ on ! /age ! field /ill rema9s d>k2 b 9 case ( a d\bly refractive /one ! field is no long] d>k except 9 c]ta9 positions ( ! /one4 ,on rotation ( ! plate1 or1 if possible1 ( ! nicols toge!r1 ! field passes f d>kness to maximum brightness f\r times 9 a complete revolution1 ! relative angul> int]vals betwe5 ^! positions be+ "r angles4 ,^! positions ( d>kness are kn[n z ! positions ( ext9ction1 & ! plate is said to ext+ui% 9 !m4 ,?is te/ is exce$+ly delicate & reveals ! d\ble refraction ev5 :5 ! greate/ diff]5ce 9 ! refractive indices is too small to be measur$ directly4 ,d\bly refractive sub/ances are ( two k9ds3 uniaxial1 9 :i* !re is "o direction ( s+le refraction1 & biaxial1 9 :i* !re are two su* directions4 ,9 ! case ( ! =m] ! direction ( "o1 ! ord9>y ray1 is precisely ! same z if ! refraction 7 s+le1 b ! refractive index ( ! o!r ray v>ies f t ( ! ord9>y ray to a second limit+ value1 ! extraord9>y refractive index1 :i* may be ei!r great] or less4 ,if ! extraord9>y is great] ?an ! ord9>y refractive index ! d\ble refraction is said to be positive2 if less1 to be negative4 ,a biaxial sub/ance is m complex4 ,x possesses ?ree pr9cipal directions1 viz41 ! bisectrices ( ! directions ( s+le refraction & ! p]p5dicul> to ! plane conta9+ !m4 ,! fir/ two correspond to ! greate/ & lea/1 & ! la/ to ! mean ( ! pr9cipal indices ( refraction4 ,if ! acute bisectrix corresponds to ! lea/ refractive index1 ! d\ble refraction is said to be positive1 & if to ! greate/1 negative4 ,! relation ( ! directions ( s+le refraction1 s1 to ! ?ree pr9cipal directions1 a1 b1 c1 is illu/rat$ 9 ,fig4 #bg = ! case ( topaz1 a positive m9]al4 ,! refractive indices ( ! rays trav]s+ "o ( ! pr9cipal directions h ! values correspond+ to ! o!r two4 ,9 ! direction a we %\ld measure ! greate/ & ! mean ( ! pr9cipal refractive indices1 9 ! direction b ! greate/ & ! lea/1 & 9 ! direction c ! mean & ! lea/4 ,! maximum am\nt ( d\ble refraction is !re=e 9 ! direction b4 ,illu/ration3 ,,fig4 #bg4--,relation ( ! two ,directions ( s+le ,refraction to ! pr9cipal ,optical ,directions 9 a ,biaxial ,cry/al4 ,9 ! exam9ation ( a facet$ /one1 ( ! mo/ usual %ape1 ! simple/ me?od is to lay ! l>ge facet1 call$ ! table1 on a glass slip & view ! /one ?r\gh ! small p>allel facet1 ! culet4 ,%\ld ! latt] n exi/1 x may frequ5tly happ5 t ow+ to int]nal reflection no light em]ges ?r\gh ! /eeply incl9$ facets4 ,?is difficulty is easily ov]come by imm]s+ ! /one 9 "s highly refract+ oil4 ,a glass plate held by h& ov] ! /one ) a drop ( ! oil betwe5 x & ! plate s]ves ! purpose1 & is p]haps a m conv5i5t me?od4 ,a /one :i* does n possess a pair ( p>allel facets %\ld be view$ ?r\gh any pair :i* are ne>ly p>allel4 ,we h /at$ t a plate ( glass has no effect on ! field4 ,suppose1 h[ev]1 x 7 view$ :5 plac$ betwe5 ! jaws ( a tight5$ vice & ?us ?r[n into a /ate ( /ra91 x w\ld !n %[ d\ble refraction1 ! am\nt ( :i* w\ld dep5d on ! /ra94 ,natural s+ly refractive sub/ances frequ5tly %[ ph5om5a ( a simil> k9d4 ,?us diamond sometimes conta9s a drop ( liquid c>bonic acid1 & ! /ra9 is reveal$ by ! col\r$ r+s surr\nd+ ! cavity :i* are se5 :5 ! /one is view$ betwe5 cross$ nicols4 ,d\ble refraction is also common 9 diamond ev5 :5 !re is no includ$ matt] to expla9 x1 & is caus$ by ! /ate ( /ra9 into :i* ! m9]al is ?r[n on release f ! enorm\s pressure "u :i* x 0 =m$4 ,o!r m9]als :i* display ^! s-call$ optical anomalies1 su* z fluor & g>net1 are n really q s+ly refractive at ord9>y temp]atures2 ea* cry/al is compos$ ( sev]al d\ble refractive individuals4 ,b all su* ph5om5a _c be confus$ ) ! *>act]s ( m9]als :i* ext+ui% 9 ! ord9>y way1 s9ce ! /one w ext+ui% 9 small pat*es & ^! w n be d>k all at ! same "t2 fur!r1 ! d\ble refraction is small1 & on revolv+ ! /one betwe5 cross$ nicols ! ext9ction is n %>p4 ,pa/e /ones are sometimes 9 a /ate ( /ra91 & display slight1 b g5]al1 d\ble refraction4 ,h5ce ! exi/5ce ( d\ble refraction does n necess>ily prove t ! /one is real & n an imitation4 ,/ones may be compos$ ( two or m individuals :i* are relat$ to ea* o!r by tw9n+1 9 :i* case ea* individual w\ld 9 g5]al ext+ui% sep>ately4 ,su* individuals w\ld be l>g] & w\ld ext+ui% m %>ply ?an ! pat*es ( an anomal\s /one4 ,illu/ration3 ,,fig4 #bh4--;,int]f]5ce ( ,light4 ,an exam9ation 9 conv]g5t light is sometimes ( s]vice4 ,an auxili>y l5s is plac$ ov] ! cond5s] s z to conv]ge ! light on to ! /one4 ,light n[ trav]ses ! /one 9 diff]5t directions2 ! m oblique ! direction ! great] ! di/ance trav]s$ 9 ! /one4 ,if x be d\bly refractive1 9 any giv5 direction !re w be 9 g5]al two rays ) diff]+ refractive indices & ! result+ effect is ak9 to ! well-kn[n ph5om5on ( ,newton's r+s1 & is an in/ance ( :at is t]m$ int]f]5ce4 ,x may be m5tion$ t ! int]f]5ce ( light 7,fig4 #bh7 expla9s su* common ph5om5a z ! col\rs ( a soap-bubble1 ! hues ( t>ni%$ /eel1 ! t9ts ( a lay] ( oil float+ on wat]1 & s on4 ,light1 aft] div]g+ f ! /one1 comes to focus a little b5ea? ! plane 9 :i* ! image ( ! /one is =m$4 ,an auxili>y l5s mu/1 !re=e1 be ins]t$ to br+ ! focal planes toge!r1 s t ! int]f]5ce picture may be view$ by means ( ! same eyepiece4 ,if a uniaxial cry/al be exam9$ along ! cry/allographic axis 9 conv]g5t light an int]f]5ce picture w be se5 ( ! k9d illu/rat$ on ,plate ,,iii4 ,! arms ( a black cross meet 9 ! c5tre ( ! field1 :i* is surr\nd$ by a s]ies ( circul> r+s1 col\r$ 9 :ite light4 ,rotation ( ! /one ab\t ! axis produces no *ange 9 ! picture4 ,illu/ration3 ,,plate ,,iii #a4 ,,uniaxial #b4 ,,uniaxial 7,circul> ,pol>ization7 #c4 ,,biaxial 7,cross$ ,bru%es7 #d4 ,,biaxial 7,hyp]bolic ,bru%es7 ,,int]f]5ce ,,figures ,a biaxial sub/ance possesses two directions 7! optic axes7 along :i* a s+le beam is transmitt$4 ,if su* a /one be exam9$ along ! l9e bisect+ ! acute angle betwe5 ! optic axes 7! acute bisectrix7 an int]f]5ce picture#d w be se5 :i* 9 p>ticul> positions ( ! /one ) respect to ! cross$ nicols takes ! =ms illu/rat$ on ,plate ,,iii4 ,z be=e1 !re is a s]ies ( r+s :i* are col\r$ 9 :ite light2 !y1 h[ev]1 are no long] circles b consi/ ( curves kn[n z lemniscates1 ( :i* ! figure ( #h is a special =m4 ,in/ead ( an un*angeable cross !re are a pair ( black 8bru%es0 :i* 9 "o position ( ! /one are hyp]bol1 & 9 t at "r angles become a cross4 ,on rotat+ ! /one we f9d t ! r+s move ) x & are unalt]$ 9 =m1 :]eas ! bru%es revolve ab\t two po9ts1 call$ ! 8eyes10 :]e ! optic axes em]ge4 ,if ! obs]vation 7 made along ! obtuse bisectrix ! angle betwe5 ! optic axes w\ld probably be too l>ge = ! bru%es to come into ! field1 & ! r+s might n be visible 9 :ite light1 ?\gh !y w\ld appe> 9 mono*romatic light4 ,9 ! case ( a sub/ance l sph5e ! figure is n s simple1 because ! positions ( ! optic axes v>y greatly = ! diff]5t col\rs & ! result is exce$+ly complex2 9 mono*romatic light1 h[ev]1 ! usual figure is visible4 ,x w\ld probably n be possible 9 ! case ( a facet$ /one to f9d a pair ( faces p]p5dicul> to ! requir$ direction4 ,nev]!less1 s long z a portion ( ! figures describ$ is 9 ! field ( view1 ! "* ( ! d\ble refraction1 :e!r uniaxial or biaxial1 may readily be det]m9$4 ,!re is yet ano!r rem>kable ph5om5on :i* mu/ n be pass$ ov]4 ,c]ta9 sub/ances1 ( :i* qu>tz is a conspicu\s example & 9 ?is respect unique among ! gem-/ones1 possess ! rem>kable prop]ty ( rotat+ ! plane ( pol>ization ( a ray ( light :i* is transmitt$ p>allel to ! optic axis4 ,if a plate ( qu>tz be cut at "r angles to ! axis & plac$ betwe5 cross$ nicols 9 :ite light1 ! field w be col\r$1 ! hue *ang+ on rotation ( "o nicol ) respect to ! o!r4 ,exam9ation 9 mono*romatic light %[s t ! field w become d>k aft] a c]ta9 rotation ( ! "o nicol ) respect to ! o!r1 ! am\nt ( :i* dep5ds on ! ?ickness ( ! plate4 ,if ! plate be view$ 9 conv]g5t light1 an int]f]5ce picture is se5 z illu/rat$ on ,plate ,,iii1 :i* is simil> to1 & yet diff]s 9 "s important p>ticul>s f ! ord9>y int]f]5ce picture ( a uniaxial /one4 ,! cross does n p5etrate beyond ! inn]mo/ r+ & ! c5tre ( ! field is col\r$ 9 :ite light4 ,if a /one %[s su* a picture1 x may be safely assum$ to be qu>tz4 ,x is int]e/+ to note t m9]als :i* possess ?is prop]ty h a spiral arrangem5t ( ! con/itu5t atoms4 ,x has already be5 rem>k$ 7p4 #bh7 t if a facet$ d\bly refractive /one be rotat$ ) "o facet always 9 contact ) ! d5se glass ( ! refractomet] ! pair ( %ad[-edges t are visible 9 ! field move up or d[n ! scale 9 g5]al f or to maximum & m9imum positions4 ,! mann] 9 :i* ?is movem5t takes place dep5ds ^u ! "* ( ! d\ble refraction & ! position ( ! facet "u obs]vation ) reg>d to ! optical symmetry ( ! /one4 ,9 ! case ( a uniaxial /one1 if ! facet be p]p5dicul> to ! cry/allographic axis1 i4e4 ! direction ( s+le refraction1 nei!r ( ! %ad[-edges w move4 ,if ! facet be p>allel to t direction1 "o %ad[-edge w move up & co9cide ) ! o!r1 :i* rema9s inv>iable 9 position1 & away f x to a second critical position2 ! latt] gives ! value ( ! extraord9>y refractive index1 & ! inv>iable %ad[-edge corresponds to ! ord9>y refractive index4 ,?is ph5om5on is display$ by ! table-facet ( mo/ t\rmal9es1 because = reasons giv5 above 7p4 #aa7 !y are z a rule cut p>allel to ! cry/allographic axis4 ,9 ! case ( facets 9 int]m$iate positions1 ! %ad[-edge correspond+ to ! extraord9>y refractive index moves1 b n to co9cid5ce ) ! inv>iable %ad[-edge4 ,! case ( a biaxial /one is m complex4 ,if ! facet be p]p5dicul> to "o ( ! pr9cipal directions "o %ad[-edge rema9s inv>iable 9 position1 correspond+ to "o ( ! pr9cipal refractive indices1 :il/ ! o!r moves betwe5 ! critical values correspond+ to ! rema9+ two ( ! pr9cipal refractive indices4 ,9 ! int]e/+ case 9 :i* ! facet is p>allel to ! two directions ( s+le refraction1 ! second %ad[-edge moves across ! "o :i* is inv>iable 9 position4 ,9 int]m$iate positions ( ! facet bo? %ad[-edges move1 & give !re=e critical values4 ,( ! int]m$iate pair1 i4e4 ! l[] maximum & ! high] m9imum1 "o corresponds to ! mean pr9cipal refractive index1 & ! o!r dep5ds ^u ! relation ( ! facet to ! optical symmetry4 ,if x is desir$ to di/+ui% betwe5 !m1 obs]vations mu/ be made on a second facet2 b = discrim9ative purposes su* exactitude is unnecess>y1 s9ce ! lea/ & ! greate/ refractive indices are all t are requir$4 ,! "* ( ! refraction ( gem-/ones is giv5 9 ,table ,v at ! end ( ! book4 ,,*apt] ,,vii ,,absorption ,,effects3 ,,col\r1 ,,di*roism1 ,,etc4 ,:5 :ite light passes ?r\gh a cut /one1 col\r effects result :i* arise f a v>iety ( causes4 ,! mo/ obvi\s is ! fundam5tal col\r ( ! /one1 :i* is due to its selective absorption ( ! light pass+ ?r\gh x1 & w\ld *>act]ize x be=e x 0 cut4 ,int]m+l$ ) ! col\r 9 a transp>5t /one is ! disp]sive effect kn[n z #8fire1' :i* has already be5 discuss$ 7p4 #bj74 ,9 _m in/ances ! want ( homog5eity is responsible = "s peculi> effects su* z opalesc5ce1 *atoyancy1 & a/]ism4 ,^! ph5om5a w n[ be consid]$ 9 full] detail4 ,,col\r ,all sub/ances absorb light to "s ext5t4 ,if ! action is slight & affects equally ! :ole ( ! visible spectrum1 ! /one appe>s :ite or col\rless4 ,usually "s portion is m /rongly absorb$ ?an ! re/1 & ! /one seems to be col\r$4 ,:at is ! precise t9t dep5ds n only ^u ! portions transmitt$ ?r\gh ! /one1 b also ^u _! relative int5sities4 ,! eye1 unlike ! e>1 has n ! p[] ( analysis & x _c ( itself det]m9e h[ a composite col\r has be5 made up4 ,inde$1 s f> z x is conc]n$1 any col\r may be exactly mat*$ by comp\nd+ 9 c]ta9 proportions ?ree simple prim>y col\rs--r$1 yell[1 & violet4 ,alex&rite1 a v>iety ( *rysob]yl1 is a curi\s & in/ructive case4 ,! balance 9 ! spectrum ( light transmitt$ ?r\gh x is su* t1 :]eas 9 daylight su* /ones appe> gre51 9 artificial light1 especially 9 gas-light1 !y are a pron\nc$ raspb]ry-r$ 7,plate ,,xxvii1 ,figs4 #aa1 #ac74 ,! ph5om5on is int5sifi$ by ! /rong di*roism *>act]i/ic ( ?is species4 ,! col\r is ! lea/ reliable "* t may be employ$ = ! id5tification ( a /one1 s9ce x v>ies consid]ably 9 ! same species1 & (t5 results f ! admixture ( "s metallic oxide1 :i* has no ess5tial "p 9 ! *emical composition & is pres5t 9 su* m9ute quantities z to be almo/ imp]ceptible by analysis4 ,:o w\ld1 = in/ance1 imag9e f _! appe>ance t /ones s m>k$ly div]se 9 hue z ruby & sapphire 7 really v>ieties ( ! same species1 corundum8 ,aga91 qu>tz1 9 spite ( ! simplicity ( its composition1 displays extreme diff]5ces ( t9t4 ,nev]!less1 c]ta9 v>ieties d possess a di/9ctive col\r1 em]ald be+ ! mo/ /rik+ example1 & 9 o!r cases ! tra9$ eye c appreciate c]ta9 *>act]i/ic subtleties ( %ade4 ,at any rate1 ! col\r is ! mo/ obvi\s ( ! physical *>act]s1 & s]ves to provide a r\gh division ( ! species1 & accord+ly 9 ,table ,,ii at ! end ( ! book ! gem-/ones are arrang$ by _! usual t9ts4 ,,di*roism ,! two rays into :i* a d\bly refractive /one splits up a ray ( light are (t5 diff]5tly absorb$ by x1 & 9 consequ5ce appe> on em]g5ce diff]5tly col\r$2 su* /ones are said to be di*roic4 ,! mo/ /rik+ in/ance is a deep-br[n t\rmal9e1 :i*1 except 9 v ?9 sections1 is q opaque to ! ord9>y ray4 ,! light transmitt$ by a plate cut p>allel to ! cry/allographic axis is !re=e plane-pol>iz$2 be=e ! inv5tion by ,nicol ( ! prism ( ,icel&-sp> kn[n by 8 "n ?is 0 ! ord9>y me?od ( obta9+ light ( ?is "* 7cf4 p4 #dc74 ,aga91 9 ! case ( kunzite & cordi]ite ! diff]5ce 9 col\r is s m>k$ z to be obvi\s to ! unaid$ eye2 b :]e ! contra/ is less pron\nc$ we require ! use ( an in/rum5t call$ a di*roscope1 :i* enables ! tw9 col\rs to be se5 side by side4 ,illu/ration3 ,,fig4 #bi4--;,di*roscope 7actual size74 ,illu/ration3 ,,fig4 #cj4--;,field ( ! ,di*roscope4 ,fig4 #bi illu/rates 9 section ! con/ruction ( a di*roscope4 ,! in/rum5t consi/s ess5tially ( a rhomb ( ,icel&-sp>1 ,s1 ( su* a l5g? z to give two contigu\s images 7,fig4 #cj7 ( a squ>e hole1 ,h1 9 "o end ( ! tube conta9+ x4 ,9 "s in/rum5ts ! t]m9al faces ( ! rhomb are gr\nd at "r angles to its l5g?1 b usually1 z 9 t depict$1 prisms ( glass1 ,g1 are cem5t$ on to ! two ends4 ,a cap ,c1 ) a slightly l>g] hole1 :i* is circul> 9 %ape1 fits on ! end ( ! tube1 & c be mov$ up & d[n x & revolv$ r\nd x1 z desir$4 ,! /one1 ,r1 to be te/$ may be directly atta*$ to x by means ( "s k9d ( wax or cem5t 9 su* a way t light :i* has trav]s$ x passes into ! w9d[1 ,h1 ( ! in/rum5t2 ! cap at ! same "t p]mits ( ! rotation ( ! /one ab\t ! axis ( ! ma9 tube ( ! in/rum5t4 ,! di*roscope %[n 9 ! figure has a /ill m conv5i5t arrangem5t3 x is provid$ ) an additional atta*m5t1 ,a1 by means ( :i* ! /one c be turn$ ab\t an axis at "r angles to ! l5g? ( ! tube1 & ?us exam9$ 9 diff]5t directions4 ,at ! o!r end ( ! ma9 tube is plac$ a l5s1 ,l1 ( l[ p[] = view+ ! tw9 images3 ! %ort tube conta9+ x c be pu%$ 9 & out = focus+ purposes4 ,_m mak]s n[ place ! rhomb close to ! l5s1 ,l1 & !reby require a mu* small] piece ( sp>2 mat]ial suitable = optical purposes is fa/ gr[+ sc>ce4 ,suppose t a plate ( t\rmal9e cut p>allel to its cry/allographic axis is fa/5$ to ! cap & ! latt] rotat$4 ,we %\ld notice1 on look+ ?r\gh ! in/rum5t1 t 9 ! c\rse ( a complete revolution !re are two positions1 ori5tat$ at "r angles to "o ano!r1 9 :i* ! t9ts ( ! two images are id5tical1 ! positions ( greate/ contra/ ( t9t be+ midway betwe54 ,if we exam9e a uniaxial /one 9 a direction at "r angles to its optic axis we obta9 ! col\rs correspond+ to ! ord9>y & ! extraord9>y rays4 ,9 any direction less incl9$ to ! axis we /ill h ! col\r = ! ord9>y ray1 b ! o!r col\r is int]m$iate 9 t9t betwe5 x & t = ! extraord9>y ray4 ,! ph5om5on pres5t$ by a biaxial /one is m complex4 ,!re are ?ree pr9cipal col\rs :i* are visible 9 diff]+ pairs 9 ! ?ree pr9cipal optical directions2 9 o!r directions ! t9ts se5 are int]m$iate betwe5 ! pr9cipal col\rs4 ,s9ce biaxial /ones h ?ree pr9cipal col\rs1 !y are sometimes said to be tri*roic or pleo*roic1 b 9 any s+le direction !y h two tw9 col\rs & %[ di*roism4 ,no diff]5ce at all w be %[n 9 directions 9 :i* a /one is s+ly refractive1 & x is !re=e always advisable to exam9e a /one 9 m ?an "o direction le/ ! fir/ happ5s to be "o ( s+le refraction4 ,= det]m9ative purposes x is n necess>y to note ! exact %ades ( t9t ( ! tw9 col\rs1 because !y v>y ) ! inh]5t col\r ( ! /one1 & are !re=e n con/ant = ! same species2 we ne$ only obs]ve1 :5 ! /one is te/$ ) ! di*roscope1 :e!r !re is any v>iation ( col\r1 &1 if s1 its /r5g?4 ,di*roism is a result ( d\ble refraction1 & _c exi/ 9 a s+ly refractive /one4 ,! conv]se1 h[ev]1 is n true & x by no means foll[s t1 because no di*roism c be detect$ 9 a /one1 x is s+ly refractive4 ,a col\rless /one1 = in/ance1 _c possibly be di*roic1 & _m col\r$1 d\bly refractive /ones--= example1 zircon--exhibit no di*roism1 or s little t x is imp]ceptible4 ,! "* is always ! bett] display$1 ! deep] ! inh]5t col\r ( ! /one4 ,! deep-gre5 alex&rite1 = in/ance1 is f> m di*roic ?an ! light] col\r$ v>ieties ( *rysob]yl4 ,if ! /one is atta*$ to ! cap ( ! in/rum5t1 ! table %\ld be turn$ t[>ds x s z to assure t ! light pass+ into ! in/rum5t has actually trav]s$ ! /one4 ,if little light ent]s ?r\gh ! opposite coign1 a drop ( oil plac$ !reon w ov]come ! difficulty 7cf4 p4 #df74 ,x is also necess>y1 = reasons m5tion$ above1 to exam9e ! /one 9 directions z f> z possible across ! girdle also4 ,a conv5i5t1 ?\gh n /rictly accurate1 me?od is to lay ! /one ) ! table facet on a table & exam9e ! light :i* has ent]$ ! /one & be5 reflect$ at t facet4 ,! /one may easily be rotat$ on ! table1 & obs]vations ?us made 9 diff]5t directions 9 ! /one4 ,c>e mu/ be ex]cis$ 9 ! case ( a facet$ /one n to mi/ake ! alt]ation 9 col\r due to disp]sion = a di*roic effect1 & ! /one mu/ be plac$ close to ! in/rum5t dur+ an obs]vation1 because o!rwise ! tw9 rays trav]s+ ! in/rum5t may h tak5 s5sibly diff]5t directions 9 ! /one4 ,di*roism is an effective te/ 9 ! case ( ruby2 its tw9 col\rs--purpli% & yell[i% r$--are 9 m>k$ contra/1 & readily di/+ui% x f o!r r$ /ones4 ,aga91 "o ( ! tw9 col\rs ( sapphire is di/9ctly m yell[i% ?an ! o!r2 ! blue sp9el1 ( :i* a good _m h be5 manufactur$ dur+ rec5t ye>s1 is s+ly refractive1 &1 ( c\rse1 %[s no diff]5ce ( t9t 9 ! di*roscope4 ,table ,,vi at ! end ( ! book gives ! /r5g? ( ! di*roism ( ! gem-/ones4 ,,absorption ,,spectra ,a /udy ( ! *romatic "* ( ! light transmitt$ by a col\r$ /one is ( no little int]e/4 ,z 0 /at$ above1 ! eye has n ! p[] ( analys+ light1 & to resolve ! transmitt$ rays into _! compon5t p>ts an in/rum5t kn[n z a spectroscope is ne$$4 ,! small #8direct-vision' type has ample disp]sion = ?is purpose4 ,x is advantage\s to employ by pref]5ce ! diffraction r ?an ! prism =m1 because 9 ! =m] ! int]vals 9 ! result+ spectrum correspond+ to equal diff]5ces ( wave-l5g? are ! same1 :]eas 9 ! latt] !y dim9i% z ! wave-l5g? increases & accord+ly ! r$ end ( ! spectrum is relatively cramp$4 ,! absorptive prop]ties ( all d\bly refractive col\r$ sub/ances v>y m or less ) ! direction 9 :i* light trav]ses !m accord+ to ! am\nt ( di*roism t !y possess1 b ! v>iation is n v noticeable unless ! /one is highly di*roic4 ,if ! light transmitt$ by a deep-col\r$ ruby be exam9$ ) a spectroscope x w be f\nd t ! :ole ( ! gre5 portion ( ! spectrum is oblit]at$ 7,fig4 #ca71 :ile 9 ! case ( a sapphire only a small portion ( ! r$ end ( ! spectrum is absorb$4 ,alex&rite af=ds especial int]e/4 ,9 ! spectrum ( ! light transmitt$ by x1 ! violet & ! yell[ are m or less /rongly absorb$1 dep5d+ ^u ! direction 9 :i* ! rays h pass$ ?r\gh ! /one 7,fig4 #ca71 & ! transmitt$ light is ma9ly compos$ ( two portions--r$ & gre54 ,! app>5t col\r ( ! /one dep5ds1 !re=e1 ^u :i* ( ! two pr$om9ates4 ,9 daylight ! resultant col\r is gre5 fleck$ ) r$ & orange1 ! ?ree pr9cipal absorptive t9ts 7cf4 p4 #bce71 b 9 artificial light1 :i* is relatively /rong] 9 ! r$ portion ( ! spectrum1 ! resultant col\r is a raspb]ry-r$1 & !re is less app>5t diff]5ce 9 ! absorptive t9ts 7cf4 ,plate ,,xxvii1 ,figs4 #aa1 #ac74 ,illu/ration3 ,,fig4 #ca4--;,absorption ,spectra4 ,9 all ! spectra j consid]$1 & 9 all l !m1 ! portions t are absorb$ are wide1 ! passage f blackness to col\r is gradual1 & ! edges delim9at+ !m are blurr$4 ,9 ! spectra ( c]ta9 zircons & 9 alm&9e g>net ! absorb$ portions1 or b&s z !y are call$1 are n>r[1 &1 moreov]1 ! transition f blackness to col\r is %>p & abrupt2 su* /ones are !re=e said to display absorption-b&s4 ,*ur* 9 #ahff 0 ! fir/ to notice ! b&s %[n by zircon 7,fig4 #ca74 ,sorby ?\ght !y port5d$ ! exi/5ce ( a new elem5t1 to :i* he gave ! "n j>gonium1 b subsequ5tly discov]$ t !y 7 caus$ by ! pres5ce ( a m9ute trace ( uranium4 ,a yell[i%-gre5 zircon %[s ! ph5om5on be/1 & x has all ! b&s %[n 9 ! figure4 ,! spectrum v>ies slightly b almo/ imp]ceptibly ) ! direction 9 ! /one4 ,o!rs %[ ! b&s 9 ! yell[ & gre51 :ile o!rs %[ only ^? 9 ! r$1 & "s only "o ( !m4 ,! b&s are n conf9$ to /ones ( any p>ticul> col\r1 or am\nt ( d\ble refraction4 ,aga91 _m zircons %[ no b&s at all1 s t _! abs5ce by no means precludes ! /one f be+ a zircon4 ,alm&9e is *>act]iz$ by a diff]5t spectrum 7,fig4 #ca74 ,! b& 9 ! yell[ is ! mo/ conspicu\s1 & is no d\bt responsible = ! purple hue ( a typical alm&9e4 ,! spectrum v>ies 9 /r5g? 9 diff]5t /ones4 ,rhodolite 7p4 #bad71 a g>net ly+ betwe5 alm&9e & pyrope1 displays ! same b&s1 & indications ( !m may be detect$ 9 ! spectra ( pyropes ( high refraction4 ,illu/ration3 ,,plate ,,iv ,,jewell]y ,,designs ,,*apt] ,,viii ,,specific ,,gravity ,x is "o ( our e>lie/ exp]i5ces t diff]5t sub/ances ( ! same size h (t5 m>k$ly diff]5t weights2 ?us1 !re is a great diff]5ce betwe5 wood & iron1 & /ill great] betwe5 wood & lead4 ,x is usual to say t iron is heavi] ?an wood1 b ! /atem5t is mislead+1 because x w\ld be possible by select+ a l>ge en\gh piece ( wood to f9d "o at lea/ z heavy z a p>ticul> piece ( iron4 ,we h1 9 fact1 to comp>e equal volumes ( ! two sub/ances1 & all ambiguity is remov$ if we speak ( relative d5sity or specific gravity--! =m] t]m be+ usually appli$ to liquids & ! latt] to solids--in/ead ( weight or heav9ess4 ,! d5sity ( wat] at #d ,c4 is tak5 z unity1 t be+ ! temp]ature at :i* x is highe/2 at o!r temp]atures x is some:at l[]1 z w be se5 f ,table ,,ix giv5 at ! end ( ! book4 ,! direct det]m9ation ( ! volume ( an irregul> solid pres5ts almo/ insup]able difficulty2 b1 =tunately1 = f9d+ ! specific gravity x is q unnecess>y to "k ! volume1 z w be %[n :5 we proce$ to consid] ! me?ods 9 use4 ,! specific gravity ( a /one is a "* :i* is )9 n>r[ limits con/ant = ea* species1 & is !re=e v useful = discrim9ative purposes4 ,x c be det]m9$ :atev] be ! %ape ( ! /one1 & x is immat]ial :e!r x be transp>5t or n2 b1 on ! o!r h&1 ! /one mu/ be unm\nt$ & free f ! sett+4 ,! me?ods = ! det]m9ation ( ! specific gravity are ( two k9ds3 9 ! fir/ a liquid is f\nd ( ! same1 or ne>ly ! same1 d5sity z ! /one1 & 9 ! second weigh+s are made & ! use ( an accurate balance is requir$4 7#a7 ,,heavy ,,liquids ,exp]im5t tells u t a solid sub/ance floats 9 a liquid d5s] ?an itself1 s9ks 9 "o less d5se1 & rema9s susp5d$ at any level 9 "o ( precisely ! same d5sity4 ,if ! /one be only slightly less d5se ?an ! liquid1 x w rise to ! surface2 if x be j z slightly d5s]1 x w z surely s9k to ! bottom1 a physical fact :i* has add$ s mu* to ! difficulty & dang] ( subm>9e manuvr+4 ,if !n we c f9d a liquid d5s] ?an ! /one to be te/$1 & place ! latt] 9 x1 ! /one w float on ! surface4 ,if we take a liquid :i* is less d5se ?an ! /one & capable ( mix+ ) ! heavi] liquid1 & add x to ! latt]1 drop by drop1 g5tly /irr+ s z to assure t ! d5sity ( ! comb9ation is uni=mly ! same ?r\gh\t1 a /age is f9ally rea*$ :5 ! /one beg9s to move d[nw>ds4 ,x has n[ v ne>ly ! d5sity ( ! liquid1 &1 if we f9d by "s means ?is d5sity1 we "k simultane\sly ! specific gravity ( ! /one4 ,v>i\s devices & me?ods are available = asc]ta9+ ! d5sity ( liquids--= in/ance1 ,we/phal's balance2 b1 ap>t f ! inconv5i5ce att5d+ su* a det]m9ation1 ! d5sity ( all liquids is some:at s]i\sly affect$ by *anges 9 ! temp]ature1 & x is !re=e bett] to make direct comp>ison ) fragm5ts ( sub/ances ( kn[n specific gravity1 :i* are t]m$ indicators4 ,if ( two fragm5ts diff]+ slightly 9 specific gravity "o floats on ! surface ( a uni=m column ( liquid & ! o!r lies at ! bottom ( ! tube conta9+ ! liquid1 we may be c]ta9 t ! d5sity ( ! liquid is int]m$iate betwe5 ! two specific gravities4 ,su* a precaution is necess>y because1 if ! liquid be a mixture ( two di/9ct liquids1 ! d5sity w\ld t5d to increase ow+ to ! great] volatility ( ! light] ( !m1 & 9 any case ! d5sity is affect$ by *ange ( temp]ature4 ,! specific gravity ( /ones is n mu* alt]$ by v>iation 9 ! temp]ature4 ,a m conv5i5t v>iation ( ?is me?od is to =m a diffusion column1 s t ! d5sity increases progressively ) ! dep?4 ,if ! /one "u te/ floats at a c]ta9 level 9 su* a column int]m$iate betwe5 two fragm5ts ( kn[n specific gravity1 its specific gravity may be f\nd by elem5t>y int]polation4 ,to =m a column ( ?is k9d ! light] liquid %\ld be p\r$ on to ! top ( ! heavi]4 ,natural diffusion gives ! mo/ p]fect column1 b1 be+ a l5g?y process1 x may conv5i5tly be quick5$ by g5tly %ak+ ! tube1 & ! column ?us =m$ gives results suffici5tly accurate = discrim9ative purposes4 ,by f> ! mo/ conv5i5t liquid = ord9>y use is me?yl5e iodide1 :i* has already be5 recomm5d$ = its high refraction4 ,x has1 :5 pure1 a d5sity at ord9>y room-temp]atures ( #ccbd1 & x is miscible 9 all proportions ) b5zol1 ^: d5sity is ,o#hh1 or toluol1 ano!r hydroc>bon :i* is some:at less volatile ?an b5zol1 & ^: d5sity is ab\t ! same1 namely1 #jhf4 ,:5 fre%1 me?yl5e iodide has only a slight t+e ( yell[1 b x rapidly d>k5s on exposure to light ow+ to ! lib]ation ( iod9e :i* is 9 a colloidal =m & _c be remov$ by filtration4 ,! liquid may1 h[ev]1 be easily cle>$ by %ak+ x up ) any sub/ance ) :i* ! iod9e comb9es to =m an iodide removable by filtration4 ,copp] fil+s answ] ! purpose well1 ?\gh r sl[ 9 action2 m]cury may also be us$1 b is n v satisfactory1 because a small am\nt may be dissolv$ & aft]w>ds be precipitat$ on to ! /one "u te/1 c>ry+ x d[n to ! bottom ( ! tube4 ,cau/ic pota% 7potassium hydroxide7 is also recomm5d$2 9 ?is case ! op]ation %\ld pref]ably be c>ri$ out 9 a special app>atus :i* p]mits ! cle> liquid to be drawn (f und]nea?1 because wat] sep>ates out & floats on ! surface4 ,9 ,fig4 #cb ?ree cut /ones1 a qu>tz 7a71 a b]yl 7b71 & a t\rmal9e 7c7 are %[n float+ 9 a diffusion column ( me?yl5e iodide & b5zol4 ,al?\gh ! b]yl is only slightly d5s] ?an ! qu>tz1 x floats at a p]ceptibly l[] level4 ,^! ?ree species are occasionally f\nd z yell[ /ones ( v simil> t9t4 ,illu/ration3 ,,fig4 #cb4--,/ones ( diff]5t ,specific ,gravities float+ 9 a ,diffusion ,column ( heavy ,liquid4 ,v>i\s o!r liquids h be5 us$ or propos$ = ! same purpose1 ( :i* two may be m5tion$4 ,! fir/ ( !m is a saturat$ solution ( potassium iodide & m]curic iodide 9 wat]1 :i* is kn[n aft] ! discov]] z ,son/adt's solution4 ,x is a cle> mobile liquid ) an amb] col\r1 hav+ at #ab ,c4 a d5sity ( #cjhe2 x may be mix$ ) wat] to any ext5t1 & is easily conc5trat$ by heat+2 moreov]1 x is durable & n subject to alt]ation ( any k9d2 on ! o!r h&1 x is highly poison\s & caut]izes ! sk91 n be+ *eck$ by album52 x also de/roys brass-w>e by amalgamat+ ! metal4 ,! second is ,kle9's solution1 a cle> yell[ liquid :i* has at #ae ,c4 a d5sity ( #cbh4 ,x consi/s ( ! boro-tung/ate ( cadmium1 ( :i* ! =mula is #i,,wo#c4;,b#b,o#c4b;,cd,o4#b;,h#b,o #af;,aq1 dissolv$ 9 wat]1 ) :i* x may be dilut$4 ,if ! salt be heat$1 x fuses at #ge ,c4 9 its own wat] ( cry/allization to a yell[ liquid1 v mobile1 ) a d5sity ( #cee4 ,kle9's solution is h>mless1 b x _c comp>e = conv5i5ce ( manipulation ) me?yl5e iodide4 ,! mo/ conv5i5t proc$ure is to h at h& ?ree glass tubes1 fitt$ ) /opp]s or corks1 to conta9 liquids ( diff]5t d5sities-- 7a7 ,me?yl5e iodide r$uc$ to #bg2 us+ z indicators or?oclase #bee1 qu>tz #bff1 & b]yl #bgd4 7b7 ,me?yl5e iodide r$uc$ to #ca2 indicators1 b]yl #bgd & t\rmal9e #caj4 7c7 ,me?yl5e iodide1 undilut$1 #ccb4 ,! pure liquid 9 ! la/ tube %\ld on no acc\nt be dilut$2 b ! d5sity ( ! o!r two liquids may be v>i$ slightly1 ei!r by add+ b5zol 9 ord] to l[] x1 or by all[+ b5zol1 :i* has f> great] volatility ?an me?yl5e iodide1 to evaporate1 or by add+ me?yl5e iodide1 9 ord] to increase x4 ,! d5sity ( ! liquids may be asc]ta9$ approximately f ! indicators4 ,a glance at ! table ( specific gravities %[s t z reg>ds ! gem-/ones me?yl5e iodide is re/rict$ 9 its application1 s9ce x c be us$ to te/ only moon/one1 qu>tz1 b]yl1 t\rmal9e1 & spodum5e2 opal & turquoise1 be+ amorph\s & m or less por\s1 %\ld n be imm]s$ 9 liquids1 le/ ! appe>ance ( ! /one be irretrievably injur$4 ,me?yl5e iodide readily s]ves to di/+ui% ! yell[ qu>tz f ! true topaz1 ) :i* jewell]s (t5 confuse x1 ! latt] /one s9k+ 9 ! liquid2 aga9 aquam>9e floats1 b ! blue topaz1 :i* is (t5 v simil> to x1 s9ks 9 me?yl5e iodide4 ,by saturat+ me?yl5e iodide ) iod9e & iod(orm1 we h a liquid 7d7 ( d5sity #cf2 a fragm5t ( topaz1 #cee1 may be us$ to indicate :e!r ! liquid has ! requisite d5sity4 ,un=tunately ?is saturat$ solution is s d>k z to be almo/ opaque1 & is1 moreov]1 v visc\s4 ,its pr9cipal use is to di/+ui% diamond1 #cece1 f ! brilliant col\rless zircon1 ) :i*1 ap>t f a te/ = h>dness1 x may easily be confus$4 ,x is easy to see :e!r ! /one floats1 z x w\ld d if a diamond4 ,to recov] a /one :i* has sunk1 ! only c\rse is to p\r (f ! liquid into ano!r tube1 because x is f> too d>k = ! position ( ! /one to be se54 ,x is possible to employ a simil> me?od = /ill d5s] /ones by hav+ rec\rse to ,retg]s's salt1 silv]-?allium nitrate4 ,?is d\ble salt is solid at ord9>y room-temp]atures1 b has ! rem>kable prop]ty ( melt+ at a temp]ature1 #ge ,c41 :i* is well bel[ ! po9t ( fusion ( ei!r ( its con/itu5ts1 to a cle>1 mobile yell[ liquid1 :i* is miscible 9 any proportion ) wat]1 & has1 :5 pure1 a d5sity ( #df4 ,! salt may be pur*as$1 or x may be prep>$ by mix+ #ajj grams ( ?allium nitrate & #fd grams ( silv] nitrate1 or simil> proportions1 9 a little wat]1 & heat+ ! :ole ov] a wat]-ba?1 keep+ x con/antly /irr$ ) a glass rod until x is liquefi$4 ,! two salts mu/ be mix$ 9 ! correct proportions1 because o!rwise ! mixture might =m o!r d\ble salts1 :i* d n melt at s l[ a temp]ature4 ,a glance at ! table ( specific gravities %[s t ,retg]s's salt may be us$ = all ! gem-/ones ) ! s+le exception ( zircon 7b74 ,!re are1 h[ev]1 "s objections to its use4 ,x is exp5sive1 &1 unless kept con/antly melt$1 x is n imm$iately available4 ,x d>k5s on exposure to /rong sunlight l all silv] salts1 /a9s ! sk9 a peculi> %ade ( purple :i* is ) difficulty remov$1 & 9 fact only by abrasion ( ! sk91 &1 l all ?allium comp\nds1 is highly poison\s4 ,x is conv5i5t to h ?ree tubes1 fitt$ z be=e ) /opp]s or corks1 to conta9 ! foll[+ liquids1 :5 heat$3-- 7e7 ,silv]-?allium nitrate1 r$uc$ to #ce2 us+ z indicators1 p]idot or idocrase #cdj & topaz #cec4 7f7 ,silv]-?allium nitrate1 r$uc$ to #dj2 indicators1 topaz #cec & sapphire #djc4 7g7 ,silv]-?allium nitrate1 undilut$1 #df4 ,! tubes mu/ be heat$ 9 "s =m ( wat]-ba?2 an ord9>y glass beak] s]ves ! purpose satisfactorily4 ,! pure salt %\ld nev] be dilut$2 b ! d5sity ( ! cont5ts ( tubes 7e7 & 7f7 may be v>i$ at w1 wat] be+ add$ 9 ord] to l[] ! d5sity1 & conc5tration by means ( evaporation or addition ( ! nitrate be+ employ$ 9 ord] to increase x4 ,to avoid ! discoloration ( ! sk91 rubb] f+]-/alls may be us$1 & ! /ones %\ld n be h&l$ until aft] !y h be5 wa%$ 9 w>m wat]4 ,! /a9+ may be m9imiz$ if ! h&s be well wa%$ 9 hot wat] be=e be+ expos$ to sunlight4 ,x is advisable to w>m ! /one to be te/$ 9 a tube conta9+ wat] be=eh& le/ ! sudd5 heat+ develop cracks4 ,a piece ( plat9um1 or1 fail+ t1 copp] wire is ( s]vice = remov+ /ones f ! tubes2 a glass rod1 spoon-%ap$ at "o end1 does equally well4 ,x mu/ be not$ t al?\gh ,retg]s's salt is absolutely h>mless to ! ord9>y gem-/ones--) ! exception ( opal & turquoise1 :i*1 z has already be5 /at$1 be+ to "s ext5t por\s1 %\ld n be imm]s$ 9 liquids--x attacks c]ta9 sub/ances1 = in/ance1 sulphides & _c be appli$ indiscrim9ately to m9]als4 ,! proc$ure describ$ above is int5d$ only z a sugge/ion2 ! me?od may be v>i$ to any ext5t at w1 dep5d+ ^u ! p>ticul> requirem5ts4 ,if su* te/s are made only occasionally1 a small] numb] ( tubes may be us$4 ,?us "o tube may be sub/itut$ = ! two m>k$ a & b1 ! liquid conta9$ 9 x be+ dilut$ z requir$1 & a s]ies ( indicators may be kept ap>t 9 small glass tubes4 ,on ! o!r h&1 any "o hav+ con/antly to te/ /ones might increase ! numb] ( tubes ) advantage1 & might f9d x useful to h at h& fragm5ts ( all ! pr9cipal species 9 ord] to make direct comp>ison4 7#b7 ,,direct ,,weigh+ ,! balance :i* is necess>y 9 bo? ! me?ods describ$ "u ?is head %\ld be capable ( giv+ results accurate to milligrams1 i4e4 ! ?\s&? "p ( a gram1 & consi/5t ) t re/riction ! beam may be z %ort z possible s z to give rapid sw+s & ?us %ort5 ! "t tak5 9 ! obs]vations4 ,a good assay balance answ]s ! purpose admirably4 ,( c\rse1 x is nev] necess>y to wait till ! balance has come to re/4 ,! mean ( ! extreme read+s ( ! po9t] atta*$ to ! beam w give ! position 9 :i* x w\ld ultimately come to re/4 ,?us1 if ! po9t] j t\*es ! eigh? division on ! "r-h& side & ! second on ! o!r1 ! mean position is ! ?ird division on ! "r-h& side 77#h #b7 #c74 ,in/ead ( ! ord9>y =m ( *emical balance1 ,we/phal's =m or ,joly's spr+-balance may be employ$4 ,weigh+s are made m quickly1 b are n s accurate4 ,9 ref9$ physical "w ! practice kn[n z d\ble-weigh+ is employ$ to obviate any slight error !re may be 9 ! susp5sion ( ! balance4 ,a c\nt]poise :i* is heavi] ?an any?+ to be weigh$ is plac$ 9 "o pan1 & weigh$4 ,! c\nt]poise is reta9$ 9 its pan ?r\gh\t ! :ole c\rse ( ! weigh+s4 ,any sub/ance ^: weight is to be f\nd is plac$ 9 ! o!r pan1 & weights add$ till ! balance sw+s truly aga94 ,! diff]5ce betwe5 ! two sets ( weights evid5tly gives ! weight ( ! sub/ance4 ,balances1 h[ev]1 are s accurately con/ruct$ t = te/+ purposes su* ref9$ precautions are n really necess>y4 ,x is immat]ial 9 :at notation ! weigh+s are made1 s long z ! same is us$ ?r\gh\t1 b ! metric sy/em ( weights1 :i* is 9 univ]sal use 9 sci5tific "w1 %\ld pref]ably be employ$4 ,jewell]s1 h[ev]1 use c>at weights1 & a subdivision to ! base #b in/ead ( decimals1 ! fractions be+ 1 1 1 #a_/af1 #a_/cb1 #a_/fd4 ,if ^! weights be employ$1 x w be necess>y to conv]t ^! fractions into decimals1 & write #ejj1 #bej1 #abe1 #a_/af #jfb1 #a_/cb #jca1 #a_/fd #jaf4 7a7 ,hydro/atic ,weigh+ ,! pr9ciple ( ?is me?od is v simple4 ,! /one1 ! specific gravity ( :i* is requir$1 is fir/ weigh$ 9 air & !n :5 imm]s$ 9 wat]4 ,if ,w & ,w be ^! weights respectively1 !n ,w ,w is evid5tly ! weight ( ! wat] displac$ by ! /one & hav+ !re=e ! same volume z x1 & ! specific gravity is ,w !re=e equal to ----------------------4 ,w ,wr ,if ! me?od ( d\ble-weigh+ _h be5 adopt$1 ! =mula w\ld be slightly alt]$4 ,?us1 suppose t c corresponds to ! c\nt]poise1 w & w to ! /one weigh$ 9 air & wat] respectively2 !n we h ,w c w & ,w c w1 & c w !re=e ! specific gravity is equal to --------------------4 w w ,illu/ration3 ,,fig4 #cc4--;,hydro/atic ,balance4 ,"s precautions are necess>y 9 practice to assure an accurate result4 ,a balance int5d$ = specific gravity "w is provid$ ) an auxili>y pan 7,fig4 #cc71 :i* hangs high en\gh up to p]mit ( ! /one be+ susp5d$ und]nea?4 ,! weight ( any?+ us$ = ! susp5sion mu/1 ( c\rse1 be det]m9$ & subtract$ f ! weight f\nd = ! /one1 bo? :5 9 air & :5 9 wat]4 ,a piece ( f9e silk is g5]ally us$ = susp5d+ ! /one 9 wat]1 b x %\ld be avoid$1 because ! wat] t5ds to creep up x & ! error ?us introduc$ affects ! fir/ place ( decimals 9 ! case ( a "o-c>at /one1 ! value be+ too high4 ,a piece ( brass wire %ap$ into a cage is mu* to be pref]r$4 ,if ! same cage be habitually us$1 its weight 9 air & :5 imm]s$ 9 wat] to ! cu/om>y ext5t 9 su* det]m9ations %\ld be f\nd once = all4 ,c>e mu/ also be tak5 to remove all air-bubbles :i* cl+ to ! /one or ! cage2 _! pres5ce w\ld t5d to make ! value too l[4 ,! surface t5sion ( wat] :i* makes x cl+ to ! wire prev5ts ! balance sw++ freely1 & r5d]s x difficult to obta9 a weigh+ correct to a milligram :5 ! wire dips into wat]4 ,?is difficulty may be ov]come by sub/itut+ a liquid su* z toluol1 :i* has a mu* small] surface t5sion4 ,z has be5 /at$ above1 ! d5sity ( wat] at #d ,c4 is tak5 z unity1 & x is !re=e necess>y to multiply ! values obta9$ by ! d5sity ( ! liquid1 :atev] x be1 at ! temp]ature ( ! obs]vation4 ,9 ,table ,,ix1 at ! end ( ! book1 are giv5 ! d5sities ( wat] & toluol at ord9>y room-temp]atures4 ,x w be notic$ t a correct read+ ( ! temp]ature is f> m important 9 ! case ( toluol4 ,example ( a ,hydro/atic ,det]m9ation ( ,specific ,gravity-- ,weight ( /one 9 air #adga gram ,weight ( /one 9 wat] #ajfg #adga #adga ,specific gravity -------------------------- ---------- #adga #ajfg #jdjd4 ,all[+ = ! d5sity ( wat] at ! temp]ature ( ! room1 :i* 0 #af ,c41 ! specific gravity is #cfcg4 ,_h no su* all[ance be5 made1 ! result w\ld h be5 f\r units too high 9 ! ?ird place ( decimals4 ,= discrim9ative purposes1 h[ev]1 su* ref9em5t is unnecess>y4 7b7 ,pycnomet]1 or ,specific ,gravity ,bottle ,! specific gravity bottle is m]ely "o ) a fairly long neck on :i* a horizontal m>k has be5 scrat*$1 & :i* is clos$ by a gr\nd glass /opp]4 ,! pycnomet] is a ref9$ v>iety ( ! specific gravity bottle4 ,x has two op5+s3 ! l>g] is int5d$ = ! ins]tion ( ! /one & ! wat]1 & is clos$ by a /opp] ?r\gh :i* a !rmomet] passes1 :ile ! o!r1 :i* is exce$+ly n>r[1 is clos$ by a /opp] fitt+ on ! outside1 & is graduat$ to facilitate ! det]m9ation ( ! height ( ! wat] 9 x4 ,! /one is weigh$ z 9 ! previ\s me?od4 ,! bottle is !n weigh$1 & fill$ ) wat] up to ! m>k & weigh$ aga94 ,! /one is n[ introduc$ into ! bottle1 & ! surplus wat] remov$ ) blott+-pap] or o!rwise until x is at ! same level z be=e1 & ! bottle ) its cont5ts is weigh$4 ,let ,w be ! weight ( ! /one1 w ! weight ( ! bottle1 ,w ! weight ( ! bottle & ! wat] conta9$ 9 x1 & ,w ! weight ( ! bottle :5 conta9+ ! /one & ! wat]4 ,!n ,w w is ! weight ( ! wat] fill+ ! bottle up to ! m>k1 & ,w w ,w is ! r$uc$ weight ( wat] aft] ! /one has be5 ins]t$2 ! diff]5ce1 ,w ,w ,w1 is ! weight ( ! ,w wat] displac$4 ,! specific gravity is !re=e ------------------------------------4 ,w ,w ,w ,z 9 ! previ\s me?od1 ?is value mu/ be multipli$ by ! d5sity ( ! liquid at ! temp]ature ( ! exp]im5t4 ,if ! me?od ( d\ble-weigh+ be adopt$1 ! =mula w be slightly modifi$4 ,( ! above me?ods1 t ( heavy liquids1 z x is usually t]m$1 is by f> ! quicke/ & ! mo/ conv5i5t = /ones ( ord9>y size1 ! specific gravity ( :i* is less ?an ! d5sity ( pure me?yl5e iodide1 namely1 #ccbd1 & by its aid a value may be obta9$ :i* is accurate to ! second place ( decimals1 a result q suffici5t = a discrim9ative te/4 ,! me?od is applicable no matt] h[ small ! /one may be1 &1 inde$1 = v small /ones x is ! only tru/wor?y me?od2 = l>ge /ones x is inconv5i5t1 n only because ( ! l>ge quantity ( liquid requir$1 b also on acc\nt ( ! difficulty 9 e/imat+ ) suffici5t c]ta9ty ! position ( ! c5tre ( gravity ( ! /one4 ,a negative det]m9ation may be ( value1 especially if att5tion be paid to ! rate at :i* ! /one falls ?r\gh ! liquid2 ! d5s] ! /one ! fa/] x w s9k1 b ! rate dep5ds also ^u ! %ape ( ! /one4 ,retg]s's salt is less conv5i5t because ( ! delay involv$ 9 w>m+ x & ( ! almo/ inevitable /a9+ ( ! h&s1 b its use pres5ts no difficulty :atev]4 ,hydro/atic weigh+ is always available1 unless ! /one be v small1 b ! necess>y weigh+s occupy consid]able "t1 & c>e mu/ be tak5 t no error creeps into ! computation1 simple ?\gh x be4 ,ev5 if ev]y?+ is at h&1 a det]m9ation is sc>cely possible "u a qu>t] ( an h\r4 ,! ?ird me?od1 :i* takes ev5 long]1 is int5d$ prim>ily = p[d]$ sub/ances1 & is n recomm5d$ = cut /ones1 unless !re happ5 to be a numb] ( t9y ones :i* are kn[n to be exactly ( ! same k9d4 ,! specific gravities ( ! gem-/ones are giv5 9 ,table ,,vii at ! end ( ! book4 ,,*apt] ,,ix ,,h>dness ,,& ,,cleavability ,e possessor ( a diamond r+ is aw>e t diamond easily scrat*es w9d[-glass4 ,if o!r /ones 7 tri$1 x w\ld be f\nd t !y also scrat*$ glass1 b n s readily1 &1 if ! exp]im5t 7 ext5d$1 x w\ld be f\nd t topaz scrat*es qu>tz1 b is scrat*$ by corundum1 :i* 9 its turn yields to ! all-p[]ful diamond4 ,!re is !re=e consid]able v>iation 9 ! capacity ( preci\s /ones to resi/ abrasion1 or1 z x is usually t]m$1 9 _! h>dness4 ,to simplify ! mode ( express+ ?is "* ! m9]alogi/ ,mohs ab\t a c5tury ago devis$ ! foll[+ arbitr>y scale1 :i* is /ill 9 g5]al use4 ,,mohs',s ,,scale ,,( ,,h>dness #a4 ,talc #b4 ,gypsum #c4 ,calcite #d4 ,fluor #e4 ,apatite #f4 ,or?oclase #g4 ,qu>tz #h4 ,topaz #i4 ,corundum #aj4 ,diamond ,a f+]-nail scrat*es gypsum & s(t] sub/ances4 ,ord9>y w9d[-glass is slightly s(t] ?an or?oclase1 & a /eel knife is slightly h>d]2 a h>d5$ file approa*es qu>tz 9 h>dness1 & easily scrat*es glass4 ,by say+ t a /one has h>dness #g we m]ely mean t x w n scrat* qu>tz1 & qu>tz w n scrat* x4 ,! numb]s indicate an ord]1 & h no quantitative significance :atev]4 ,?is is an important po9t ab\t :i* mi/akes are (t5 made4 ,we mu/ n1 = in/ance1 suppose t diamond has twice ! h>dness ( apatite4 ,z a matt] ( fact1 ! int]val betwe5 diamond & corundum is imm5sely great] ?an t betwe5 ! latt] & talc1 ! s(te/ ( m9]al sub/ances4 ,int]m$iate degrees ( h>dness are express$ by fractions4 ,! numb] #h = *rysob]yl means t x scrat*es topaz z easily z x itself is scrat*$ by corundum4 ,pyrope g>net is slightly h>d] ?an qu>tz1 & its h>dness is said !re=e to be #g4 ,delicate te/s %[ t ! /ructure ( all cry/alliz$ sub/ances is m or less gra9$1 l t ( wood1 & ! h>dness = ! same /one v>ies 9 diff]5t directions4 ,kyanite is unique 9 ?is respect1 s9ce its h>dness ranges f #e to #g2 x c !re=e be scrat*$ by a knife 9 "s directions1 b n 9 o!rs4 ,9 mo/ sub/ances1 h[ev]1 ! range is s small z to be q imp]ceptible4 ,slight v>iation is also app>5t 9 ! h>dness ( diff]5t specim5s ( ! same species4 ,! diamonds f ,borneo & ,new ,s\? ,wales are s di/9ctly h>d] ?an ^? f ,s\? ,africa & o!r localities t1 :5 fir/ discov]$1 "s difficulty 0 exp]i5c$ 9 cutt+ !m4 ,aga91 lapid>ies f9d t :ile ,ceylon sapphires are h>d] ?an rubies1 ,ka%mir sapphires are s(t]4 ,h>dness is a "* ( fundam5tal importance 9 a /one int5d$ = ornam5tal we>1 s9ce ^u x dep5ds ! durability ( ! poli% & brilliancy4 ,ord9>y du/ is l>gely compos$ ( gra9s ( s&1 :i* is qu>tz 9 a m9ute =m1 & a gem-/one %\ld !re=e be at lea/ z h>d z t4 ,pa/e imitations are little h>d] ?an #e1 & consequ5tly1 z exp]i5ce %[s1 _! poli% does n survive a few weeks' we>4 ,h>dness is1 h[ev]1 ( little use z a discrim9ative te/ except = di/+ui%+ betwe5 topaz or h>d] /one & pa/e4 ,diamond is s mu* h>d] ?an o!r /ones t x w leave a cut 9 glass q diff]5t f ! scrat* ( ev5 corundum4 ,pa/e1 be+ s s(t1 readily yields to ! file1 & is ?us easily di/+ui%$ f g5u9e /ones4 ,9 apply+ ! te/ to a cut /one1 x is be/ to remove x f its m\nt & try ! effect on ! girdle1 because any scrat* w\ld be conceal$ aft]w>ds by ! sett+4 ,any m>k %\ld be rubb$ ) ! f+] to assure t x is n due to p[d] f ! scrat*+ ag5t2 confusion may (t5 be caus$ 9 ?is way :5 ! two sub/ances are ( ne>ly ! same h>dness4 ,! degrees ( h>dness ( ! gem-/ones are giv5 9 ,table ,,viii at ! end ( ! book4 ,x mu/ n be ov]look$ t extreme h>dness is compatible ) cleavability 9 c]ta9 directions intimately connect$ ) ! cry/all9e /ructure2 ! prop]ty1 9 fact1 *>act]izes _m m9]al species ( diff]5t degrees ( h>dness4 ,diamond c be split 9 f\r directions p>allel to ! faces ( ! regul> octah$ron1 a prop]ty utiliz$ by ! lapid>y = %ap+ a /one previ\s to cutt+ x4 ,topaz cleaves ) consid]able ease at "r angles to ! pr9cipal cry/allographic axis4 ,felsp> has two directions ( cleavage ne>ly at "r angles to "o ano!r4 ,! new gem-/one1 kunzite1 ne$s cauti\s h&l+ ow+ to ! facility ) :i* x splits 9 two directions mutually incl9$ at ab\t #gj4 ,all /ones are m or less brittle1 & w be fractur$ by a suffici5tly viol5t bl[1 b ! irregul> surface ( a fracture _c be mi/ak5 = ! brilliant flat surface giv5 by a cleavage4 ,! cleavage is by no means induc$ ) equal facility 9 ! species m5tion$ above4 ,a consid]able ef=t is requir$ to split diamond1 b 9 ! case ( topaz or kunzite incipi5t cleavage 9 ! %ape ( flaws may be />t$ if ! /one be m]ely dropp$ on to a h>d floor4 ,,*apt] ,x ,,electrical ,,*>act]s ,! def9ite ori5tation ( ! molecul> arrangem5t ( cry/alliz$ sub/ances leads 9 _m cases to attributes :i* v>y ) ! direction & are reveal$ by ! electrical prop]ties4 ,if a t\rmal9e cry/al be heat$ 9 a gas or alcohol flame x becomes *>g$ ) electricity1 &1 s9ce x is at ! same "t a bad conductor1 /atic *>ges ( opposite sign appe> at ! two ends4 ,topaz %[s simil> *>act]s1 b 9 a less] degree4 ,qu>tz1 if treat$ 9 ! same way1 %[s *>ges ( opposite sign on diff]5t sides1 b ! ph5om5on may be mask$ by intimate tw9n+ & consequ5t ov]lapp+ ( ! contr>y areas4 ,! ph5om5on may also be se5 :5 ! /ones are cut4 ,! mo/ conv5i5t me?od = detect+ ! exi/5ce ( ! electrical *>ges is t devis$ by ,kundt4 ,a p[d] consi/+ ( a mixture ( r$ lead & sulphur is plac$ 9 a bell[s arrangem5t & bl[n ?r\gh a sieve at "o end on to ! /one4 ,ow+ to ! friction ! p>ticles become electrifi$--r$ lead positively & sulphur negatively--& are attract$ by ! *>ges ( oppos+ sign1 :i* w !re=e be betray$ by ! col\r ( ! du/ at ! correspond+ spot4 ,! p[d] mu/ be kept dry2 o!rwise a *emical reaction may occur lead+ to ! =mation ( lead sulphide1 recognizable by its black col\r4 ,bck] has sugge/$ z an alt]native ! use ( sulphur1 col\r$ r$ ) c>m9e1 ! negative elem5t1 & yell[ lycopodium1 ! positive elem5t4 ,diamond1 topaz1 & t\rmal9e are p[]ful en\gh1 :5 electrifi$ by friction ) a clo?1 to attract fragm5ts ( pap]1 ! electrification be+ positive4 ,amb] develops consid]able negative electricity :5 treat$ 9 a simil> mann]4 ,diamond is transluc5t to ! ,rntg5 7,x7 rays2 glass1 on ! o!r h&1 is opaque to !m1 & ?is te/ di/+ui%es brilliants f pa/e imitations4 ,diamond also1 unlike glass1 phosphoresces "u ! influ5ce ( radium1 a prop]ty *>act]iz+ also kunzite4 ,x w be se5 t ! electrical *>act]s1 al?\gh ( consid]able int]e/ to ! /ud5t1 are1 on acc\nt ( _! limit$ application & difficulty ( te/1 ( little s]vice = ! discrim9ation ( gem-/ones4 ,,"p ,i--,,section ,b ,,! ,,te*nology ,,( ,,gem-,,/ones ,,*apt] ,,xi ,,unit ,,( ,,weight ,! sy/em 9 use = record+ ! weights ( preci\s /ones is peculi> to jewell]y4 ,! unit1 :i* is kn[n z ! c>at1 be>s no simple relation to any unit t has exi/$ among ,european nations1 & indubitably has be5 introduc$ f ! ,ea/4 ,:5 man 9 e>ly days s\ght to record ! weights ( small objects1 he made use ( ! mo/ conv5i5t se$s or gra9s :i* 7 easily obta9able & 7 at ! same "t ne>ly uni=m 9 size4 ,9 ,europe ! smalle/ unit ( weight 0 ! b>ley gra94 ,simil>ly 9 ! ,ea/ ! se$s ( "s legum9\s tree 7 select$4 ,^? ( ! locu/-tree1 ,c]atonia siliqua1 :i* is common 9 ! c\ntries bord]+ ! ,m$it]ranean1 on ! av]age weigh s ne>ly a c>at t !y almo/ c]ta9ly =m$ ! orig9al unit4 ,x is1 inde$1 f ! ,greek 1 little horn1 :i* ref]s to ! %ape ( ! pods1 t ! ^w c>at is d]iv$4 ,x is "o ( ! ecc5tricities ( ! jewell]y trade t precision %\ld n h be5 giv5 to ! unit ( weight4 ,n only does x v>y at mo/ ( ! trade c5tres 9 ! _w1 b x is n ev5 always con/ant at ea* c5tre4 ,! diff]5ce is negligible 9 ! case ( s+le /ones ( ord9>y size1 b becomes a matt] ( s]i\s importance :5 l>ge /ones1 or p>cels ( small /ones1 are b\ght & sold1 p>ticul>ly :5 ! /ones are v co/ly4 ,attempts h be5 made at v>i\s times to secure a uni=m /&>d1 b z yet ) only p>tial success4 ,9 #ahga ! c>at def9$ z ! equival5t ( #jbjejj gram 0 sugge/$ at a meet+ ( ! pr9cipal jewell]s ( ,p>is & ,london1 & 0 ev5tually accept$ 9 ,p>is1 ,new ,york1 ,leipzig1 & ,borneo4 ,x has1 h[ev]1 rec5tly be5 recogniz$ t 9 view ( ! gradual spread ( ! metric sy/em ( weights & measures ! mo/ satisfactory unit is ! metric c>at ( "o-fif? 7#jb7 gram4 ,?is has n[ be5 con/itut$ ! legal c>at ( ,france & ,belgium1 & no d\bt o!r c\ntries w foll[ _! example4 ,! c>at weight obta9+ 9 ,london weighs ab\t #jbjecj gram1 & ! approximate equival5ts 9 ! gram at o!r c5tres are z foll[s3--,flor5ce #jaigbj1 ,madrid #jbjeci1 ,b]l9 #jbjedd1 ,am/]dam #jbjegj1 ,lisbon #jbjege1 ,frank=t-on-,ma9 #jbjegg1 ,vi5na #jbjfac1 ,v5ice #jbjgjj1 & ,madras #jbjgce4 ,! gram itself is inconv5i5tly l>ge to s]ve z a unit = ! g5]ality ( /ones met ) 9 ord9>y jewell]y4 ,! notation = express+ ! sub-multiples ( ! c>at =ms ano!r curi\s ecc5tricity4 ,fractions are us$ :i* are p[]s ( ! half3 ?us ! half1 ! half ( t1 i4e4 ! qu>t]1 & s on d[n to ! sixty-f\r?1 & ! weight ( a /one is express$ by a s]ies ( fractions1 e4g4 #c #a_/fd c>ats4 ,9 ! case ( diamond a s+le unr$uc$ fraction to ! base #fd is sub/itut$ 9 place ( ! s]ies ( s+le fractions1 & ! weight ( a /one is /at$ ?us1 #d-dj_/fd c>ats4 ,) ! introduction ( ! metric c>at ! m conv5i5t & rational decimal notation w\ld1 ( c\rse1 be simultane\sly adopt$4 ,illu/ration3 ,figs4 #cd-ci4--;,exact ,sizes ( ,brilliants ( v>i\s ,weights4 ,figs4 #cd-ci illu/rate ! exact sizes ( diamonds ( c]ta9 weights1 :5 cut z brilliants4 ,! sizes ( o!r /ones dep5ds ^u _! specific gravity1 ! weight v>y+ z ! volume multipli$ by ! specific gravity4 ,qu>tz1 = in/ance1 has a l[ specific gravity & w\ld be p]ceptibly l>g]1 weight = weight2 zircon1 on ! o!r h&1 w\ld be small]4 ,x has be5 f\nd m conv5i5t to select a small] unit 9 ! case ( pe>ls1 namely1 ! pe>l-gra91 f\r ( :i* g to ! c>at4 ,/5cil gauges are 9 use = measur+ approximately ! weight 9 c>ats ( diamond brilliants & ( pe>ls1 :i* 9 bo? in/ances mu/ be unm\nt$4 ,a m accurate me?od = det]m9+ ! weight ( diamonds has be5 devis$ by ,*>les ,moe1 :i* is applicable to ei!r unm\nt$ or m\nt$ /ones4 ,by means ( callip]s1 :i* read to ?ree-t5?s ( a millimetre1 ! diamet] & ! dep? ( ! /one are measur$1 & by ref]5ce to a table ! correspond+ weight is f\nd2 all[ance is made = ! v>y+ f95ess ( ! girdle1 &1 9 ! case ( l>ge /ones1 = ! v>iation f a /rictly circul> section4 ,s9ce ?is *apt] 0 writt5 ! movem5t 9 fav\r ( ! metric c>at has made rapid progress1 & ?is unit w soon h be5 adopt$ z ! legal /&>d all ov] ! _w1 ev5 9 c\ntries1 su* z ! ,briti% ,isles & ! ,unit$ ,/ates1 :]e ! metric sy/em is n 9 use4 ,! advantage ( an int]national unit is too obvi\s to ne$ argu+4 ,,*apt] ,,xii ,,fa%ion+ ,,( ,,gem-,,/ones ,al?\gh _m ( ! gem-/ones h be5 end[$ by nature ) brilliant lu/r\s faces & display sc9tillat+ reflections f _! surfaces1 yet _! =m is nev] su* z to reveal to full p]fection ! optical qualities ^u :i* _! *>m dep5ds4 ,moreov]1 ! natural faces are seldom p]fect2 z a rule ! /ones are brok5 ei!r ?r\gh "s convulsion ( ! e>?'s cru/ or 9 c\rse ( extraction f ! matrix 9 :i* !y h la91 or !y are r\gh5$ by attrition aga9/ matt] ( great] h>dness1 or worn by ! prolong$ action ( wat]1 or et*$ by solv5ts4 ,beautiful octah$ra ( diamond or sp9el h be5 m\nt$ )\t fur!r embelli%m5t1 b ev5 _! appe>ance might h be5 mu* improv$ at ! lapid>y's h&s4 ,by f> ! olde/ ( ! exi/+ /yles ( cutt+ is ! r\nd$ %ape kn[n z cabo*on1 a ,fr5* ^w d]iv$ f ! ,lat9 cabo1 a head4 ,9 ! days ( ! ,roman ,empire ! s(t] /ones 7 (t5 treat$ 9 ?is mann]2 su* /ones 7 suppos$ to be b5eficial to ^? suff]+ f %ort-sight$ness1 ! reason no d\bt be+ t transp>5t /ones :5 cut z a d\ble cabo*on =m$ a convex l5s4 ,accord+ to ,pl9y1 ,n]o _h an em]ald ?us cut1 ?r\gh :i* he 0 accu/om$ to view ! gladiatorial %[s4 ,?is /yle ( cutt+ 0 long a fav\rite = col\r$ /ones1 su* z em]ald1 ruby1 sapphire1 & g>net1 b has be5 ab&on$ 9 mod]n practice except = opaque1 semi-opaque1 & imp]fect /ones4 ,! crimson g>net1 :i* 0 at "o "t kn[n by ! "n c>buncle1 0 s sy/ematically ?us cut t ! ^w has come to signify a r$ g>net ( ?is =m4 ,x 0 a popul> broo*-/one ) our gr&mo!rs1 b is no long] 9 vogue4 ,! ,ea/ /ill reta9s a ta/e = /ones cut 9 ! =m ( beads & drill$ ?r\gh ! c5tre2 ! beads are ?read$ toge!r1 & worn z necklaces4 ,! native lapid>ies (t5 improve ! col\r ( pale em]alds by l9+ ! hole ) gre5 pa9t4 ,illu/ration3 ,,plate ,v ,,jewell]y ,,designs ,illu/ration3 ,,fig4 #dj4--;,d\ble 7,convex7 ,cabo*on4 ,illu/ration3 ,,fig4 #da4--,simple ,cabo*on4 ,! cabo*on =m may be ( ?ree diff]5t k9ds4 ,9 ! fir/1 ! d\ble cabo*on 7,fig4 #dj71 bo? ! upp] & ! "u sides ( ! /ones are curv$4 ,! curvature1 h[ev]1 ne$ n be ! same 9 ea* case2 inde$1 x is usually m>k$ly diff]5t4 ,moon/ones & />/ones are g5]ally cut v /eep above & %all[ und]nea?4 ,occasionally a ruby or a sapphire is1 :5 cut 9 ?is way1 set ) ! %all[ side above1 because ! light t has p5etrat$ into ! /one f above is m :olly reflect$ f a /eep surface ) consequ5t increase 9 ! gl[ ( col\r f ! /one4 ,opals are always cut high] on ! expos$ side1 b ! slope ( ! surface v>ies consid]ably2 !y are g5]ally cut /eeply :5 requir$ = m\nt+ 9 r+s4 ,*rysob]yl cat's-eyes are inv>iably cut ) curv$ bases 9 ord] to pres]ve ! weight z great z possible4 ,! d\ble cabo*on =m ) a %all[ surface und]nea? m]ges into ! second k9d 7,fig4 #da7 9 :i* ! "u side is plane1 ! =m commonly employ$ = qu>tz cat's-eyes1 & occasionally also = c>buncles4 ,9 ?is type ! plane side is inv>iably m\nt$ d[nw>ds4 ,9 ! ?ird =m 7,fig4 #db7 ! curvature ( ! "u surface is rev]s$1 & ! /one is holl[$ out into a concave %ape4 ,?is /yle is res]v$ = d>k /ones1 su* z c>buncles1 :i*1 if cut at all ?ick1 w\ld %[ v little col\r4 ,a piece ( foil is (t5 plac$ 9 ! holl[ 9 ord] to increase ! reflection ( light1 & ?us to height5 ! col\r effect4 ,illu/ration3 ,,fig4 #db4--;,d\ble 7,concavo-convex7 ,cabo*on4 ,9 e>ly days x 0 suppos$ t ! extreme h>dness ( diamond preclud$ ! possibility ( fa%ion+ x1 & up to ! fifte5? c5tury all t 0 done 0 to remove ! gum-l sk9 :i* disfigur$ ! ,indian /ones & to poli% ! natural facets4 ,! fir/ notable advance 0 made 9 #adge1 :5 ,l\is de ,b]quem discov]$1 z x is said q by accid5t1 t two diamonds if rubb$ toge!r gr\nd ea* o!r4 ,) confid5t c\rage he essay$ ! new art ^u ?ree l>ge /ones entru/$ to him by ,*>les ! ,bold1 to ! entire satisfaction ( 8 patron4 ,! use ( :eels or discs *>g$ ) diamond du/ soon foll[$1 b at fir/ ! lapid>ies ev9c$ _! victory ov] su* /ubborn mat]ial by gr9d+ diamond into div]s fanta/ic %apes1 & fail$ to realize h[ mu* might be done to enhance ! intr9sic beauty ( ! /ones by ! means n[ at _! disposal4 ,! ,indian lapid>ies arriv$ at ! same discov]y indep5d5tly1 & ,tav]ni] f\nd1 :5 visit+ ! c\ntry 9 #affe1 a l>ge numb] ( diamond cutt]s actively employ$4 ,if ! /one 7 p]fectly cle>1 !y cont5t$ !mselves ) poli%+ ! natural facets2 b if x conta9$ flaws or specks1 !y cov]$ x ) num]\s small facets haphaz>dly plac$4 ,! /one 0 inv>iably left 9 almo/ its orig9al %ape1 & no ef=t 0 made to improve ! symmetry4 ,illu/ration3 ,,fig4 #dc4--,table ,cut 7top view74 ,illu/ration3 ,,fig4 #dd4--,table ,cut 7side view74 ,= a long "t little fur!r progress 0 made1 & ev5 ne>ly a c5tury aft] ,b]quem ! only regul> patt]ns kn[n to ,k5tmann1 :o wrote 9 #aefb1 7 ! diamond-po9t & ! diamond-table 7,figs4 #dc-dd74 ,! =m] consi/$ ( ! natural octah$ron facets gr\nd to regul> %ape1 & 0 long employ$ = ! m9ute /ones :i* 7 set 9 conjunction ) l>ge col\r$ /ones 9 r+s4 ,! table repres5t$ consid]ably great] lab\r4 ,"o corn] ( ! regul> octah$ron 0 gr\nd d[n until ! artificial facet ?us produc$ 0 half ! wid? ( ! /one1 :ile ! opposite corn] 0 slightly gr\nd4 ,/ill ano!r c5tury elaps$ be=e ! introduction ( ! rose patt]n1 :i* compris$ tw5ty-f\r triangul> facets & a flat base 7,figs4 #de-df71 ! /one be+ ne>ly hemisph]ical 9 %ape4 ,?is /yle is said to h be5 ! inv5tion ( ,c>d9al ,maz>91 b probably he 0 ! fir/ to h diamonds ( any consid]able size cut 9 ?is =m4 ,at ! pres5t day only t9y /ones are cut z roses4 ,illu/ration3 ,,fig4 #de4--,rose ,cut 7top view74 ,a few m ye>s pass$ away1 & at l5g? at ! close ( ! sev5te5? c5tury diamond came by its own :5 ,v9c5zio ,p]uzzi1 a ,v5etian1 introduc$ ! brilliant =m ( cutt+1 & reveal$ = ! fir/ "t its amaz+ #8fire4' ,except = m9or *anges ?is =m rema9s to ?is day ! /&>d /yle = ! %ape ( diamond1 & ! ^w brilliant is commonly employ$ to d5ote diamond cut 9 ?is way4 ,s obvi\sly & m>k$ly sup]ior is ! /yle to all o!rs t ^u its discov]y ! own]s ( l>ge roses _h !m re-cut z brilliants despite ! loss 9 weight necessitat$ by ! *ange4 ,illu/ration3 ,,fig4 #df4--,rose ,cut 7side view74 ,! brilliant =m is d]iv$ f ! old table by increas+ ! numb] ( facets & slightly alt]+ ! angles p]ta9+ to ! natural octah$ron4 ,9 a p]fect brilliant 7,figs4 #dg-di7 !re are altoge!r #eh facets1 #cc above & #be bel[ ! girdle1 z ! edge sep>at+ ! upp] & l[] portions ( ! /one is t]m$1 :i* are arrang$ 9 ! foll[+ mann]4 ,eight />-facets1 triangul> 9 %ape1 imm$iately surr\nd ! l>ge table-facet4 ,next come f\r l>ge templets or bezels1 quadrilat]al 9 =m1 arrang$ 9 pairs on opposite sides ( ! table-facet1 ! f\r quo9s or loz5ges1 simil> 9 %ape1 com+ int]m$iately betwe5 !m2 9 mod]n practice1 h[ev]1 ^! two sets are id5tical 9 %ape & size1 & !re are consequ5tly eight facets ( ! same k9d in/ead ( two sets ( f\r4 ,! eight cross or skew facets & ! eight skill facets1 9 bo? sets ! %ape be+ triangul>1 =m ! b\nd>y ( ! girdle2 mod]n brilliants usually h in/ead sixte5 facets ( ! same %ape & size4 ,! above #cc facets lie above ! girdle & =m ! cr[n ( ! /one4 ,imm$iately opposite & p>allel to ! table is ! t9y culet4 ,next to ! latt] come ! f\r l>ge pavilion facets ) ! f\r quo9s int]m$iately betwe5 !m1 bo? sets be+ five-sid$ b ne>ly quadrilat]al 9 %ape2 ^! aga9 are usually comb9$ into eight facets ( ! same size4 ,eight cross facets & eight skill facets1 bo? sets1 l ^? 9 ! cr[n1 be+ triangul> 9 %ape1 =m ! l[] side ( ! girdle2 ^! also are g5]ally unit$ into a set ( sixte5 simil> facets4 ,^! #be facets :i* lie bel[ ! girdle comprise ! #8pavilion1' or base ( ! /one4 ,9 a regul> /one prop]ly cut a templet is ne>ly p>allel to a pavilion1 & an upp] to a l[] cross facet4 ,! cont\r ( ! girdle is usually circul>1 b occasionally assumes less symmetrical %apes1 z = in/ance 9 drop-/ones or p5deloques1 & ! facets are at ! same "t di/ort$4 ,! numb] ( facets may ) advantage be increas$ 9 ! case ( l>ge /ones4 ,an additional set ( eight /> facets is (t5 plac$ r\nd ! culet1 ! total numb] !n be+ #ff4 ,x may be m5tion$ t ! l>ge/ /one cut f ! ,cull9an has ! exceptional numb] ( #gd facets4 ,illu/ration3 ,,fig4 #dg4--;,brilliant ,cut 7top view74 ,illu/ration3 ,,fig4 #dh4--;,brilliant ,cut 7base view74 ,illu/ration3 ,,fig4 #di4--;,brilliant ,cut 7side view74 ,9 ord] to secure ! f9e/ optical effect c]ta9 proportions h be5 f\nd necess>y4 ,! dep? ( ! cr[n mu/ be "o-half t ( ! base1 & !re=e "o-?ird ! total dep? ( ! /one1 & ! wid? ( ! table mu/ be slightly less ?an half t ( ! /one4 ,! culet %\ld be q small1 n m 9 wid? ?an "o-six? ( ! table2 x is1 9 fact1 n requir$ at all except to avoid ! dang] ( ! po9t spl9t]+4 ,! girdle %\ld be z ?9 z is compatible ) /r5g? suffici5t to prev5t *ipp+ 9 ! process ( m\nt+ ! /one2 if x 7 left ?ick1 ! r\gh edge w\ld be visible by reflection at ! l[] facets1 & w\ld1 especially if at all dirty1 s]i\sly affect ! quality ( ! /one4 ,! %ape ( ! /one is l>gely det]m9$ by ! sizes ( ! templets 9 ! cr[n & ! pavilions 9 ! base z comp>$ ) t ( ! table1 or1 :at comes to ! same ?+1 by ! incl9ations at :i* !y are cut to t facet4 ,if ! table _h actually half ! wid? ( ! /one1 ! angle#e betwe5 x & a templet w\ld be exactly half a "r angle or #de2 x is1 h[ev]1 made some:at small]1 namely1 ab\t #dj4 ,a pavilion1 be+ p>allel to a templet1 makes a simil> angle ) ! culet4 ,! cross facets are m /eeply incl9$1 & make an angle ( ab\t #de ) ! table or ! culet1 z ! case may be4 ,! /> facets1 on ! o!r h&1 slant p]ceptibly less1 & make an angle ( only ab\t #bf ) ! table4 ,a latitude ( "s #d or #e is possible )\t s]i\sly affect+ ! #8fire' ( ! /one4 ,! object ( ! disposition ( ! facets on a brilliant is to assure t all ! light t ent]s ! /one1 pr9cipally by way ( ! table1 is :olly reflect$ f ! base & em]ges ?r\gh ! cr[n1 pref]ably by way ( ! incl9$ facets4 ,a brilliant-cut diamond1 if view$ ) ! table betwe5 ! obs]v] & ! light1 appe>s q d>k except = ! small am\nt ( light escap+ ?r\gh ! culet4 ,light %\ld !re=e fall on ! l[] facets at angles great] ?an ! critical angle ( total-reflection1 :i* = diamond is #bd #bf4 ,! pavilions %\ld be incl9$ prop]ly at d\ble ?is angle1 or #dh #eb1 to ! culet2 b a ray t em]ges at a pavilion 9 ! actual arrangem5t ent]$ ! table at ne>ly graz+ incid5ce1 & ! am\nt ( light ent]+ ?is facet at su* acute p]spective is negligible4 ,on ! o!r h&1 aft] reflection at ! base light mu/1 9 ord] to em]ge1 fall on ! cr[n at less ?an ! critical angle ( total-reflection4 ,9 ,fig4 #ej are %[n diagrammatically ! pa?s ( rays t ent]$ ! table 9 div]s ways4 ,! ray em]g+ aga9 at ! table suff]s little or no disp]sion & is almo/ :ite1 b ^? com+ out ?r\gh ! incl9$ facets are split up into ! ra9b[ effect1 kn[n z #8fire1' = :i* diamond is s fam\s4 ,x is 9 ord] t s mu* ( ! light ent]+ by ! table may em]ge ?r\gh ! incl9$ facets ( ! cr[n t ! pavilions are incl9$ at n mu* m ?an #dj to ! culet4 ,x might be sugge/$ t in/ead ( be+ facet$ ! /one %\ld be conically %ap$1 truncat$ above & ne>ly complete bel[4 ,! result w\ld no d\bt be /eadi]1 b1 on ! o!r h&1 f> less pleas+4 ,x is ! ev]-*ang+ nuance t *iefly attracts ! eye2 n[ a brilliant fla% ( pure/ :ite1 anon a gleam ( c]ulean blue1 wax+ to ri*e/ orange & dy+ 9 a crimson gl[1 all int]m+l$ ) ! manifold glitt] f ! surface ( ! /one4 ,absolute cleanl9ess is ess5tial if ! full beauty ( any /one is to be realiz$1 b ?is is p>ticul>ly true ( diamond4 ,if ! back ( ! /one be clogg$ ) grease & dirt1 z s (t5 happ5s 9 claw-set r+s1 light is no long] :olly reflect$ f ! base2 mu* ( x escapes1 & ! am\nt ( #8fire' is s]i\sly dim9i%$4 ,illu/ration3 ,,fig4 #ej4--;,c\rse ( ! ,rays ( ,light pass+ ?r\gh a ,brilliant4 ,ne$less to /ate1 lapid>ies make no c>eful angul> measurem5ts :5 cutt+ /ones1 b judge ( ! position ( ! facets entirely by eye4 ,x sometimes !re=e happ5s t ! p]missible limits are ov]/epp$1 9 :i* ev5t ! /one is dead & may resi/ all ef=ts to vivify x %ort ( ! h]oic c\rse ( re-cutt+ x1 too exp5sive a treatm5t 9 ! case ( small /ones4 ,! factors t gov]n ! prop]ties ( a brilliant-cut /one are l>ge col\r-disp]sion1 high refraction1 & fre$om f any trace ( intr9sic col\r4 ,! only gem-/one t c vie ) diamond 9 ^! respects is zircon4 ,al?\gh x is r>e to f9d a zircon naturally )\t col\r1 yet _m k9ds are easily depriv$ ( _! t9t by ! application ( heat4 ,a brilliant-cut zircon is1 inde$1 f> f readily di/+ui%$ by eye f diamond1 & has probably (t5 pass$ z "o1 b x may easily be id5tifi$ by its l>ge d\ble refraction 7cf4 p4 #da7 & inf]ior h>dness4 ,! rema9+ col\rless /ones1 su* z :ite sapphire1 topaz1 & qu>tz 7rock-cry/al71 h insuffici5t refractivity to give total-reflection at ! base1 &1 moreov]1 !y are comp>atively defici5t 9 #8fire4' ,illu/ration3 ,,fig4 #ea4--,/ep- or ,trap-,cut 7top view74 ,illu/ration3 ,,fig4 #eb4--,/ep- or ,trap-,cut 7side view74 ,a popul> /yle ( cutt+ :i* is mu* 9 vogue = col\r$ /ones is ! /ep- or trap-cut1 consi/+ ( a table & a s]ies ( facets ) p>allel horizontal edges 7,figs4 #ea-eb7 above & bel[ ! girdle2 9 rec5t jewell]y1 h[ev]1 ! top ( ! /one is (t5 brilliant-cut4 ,! cont\r may be oblong1 squ>e1 loz5ge1 or he>t-%ap$1 or h less regul> =ms4 ,! table is sometimes slightly r\nd$4 ,s9ce ! object ( ?is /yle is prim>ily to display ! intr9sic col\r ( ! /one & n s mu* a brilliant play ( light f ! int]ior1 no attempt is made to secure total-reflection at ! l[] facets4 ,! /one !re=e v>ies 9 dep? accord+ to its t9t2 if d>k1 x is cut %all[1 le/ light be :olly absorb$ )91 & ! /one appe> practically opaque1 b if light1 x is cut deep1 9 ord] to secure fullness ( t9t4 ,mu* precision 9 %ape & disposition ( ! facets is n dem&$1 & ! /ones are usually cut 9 su* a way t1 provid$ ! desir$ effect is obta9$1 ! weight is kept z great z possible2 we may recall t /ones are sold by weight4 ,9 consid]+ :at w be ! optical effect ( any p>ticul> %ape1 reg>d mu/ be _h to ! effective col\r ( ! transmitt$ light4 ,= in/ance1 al?\gh sapphire & ruby belong to ! same species & h ! same refractive indices1 yet1 s9ce ! =m] transmits ma9ly blue & ! latt] r$ light1 !y h = practical purposes appreciably diff]5t indices1 & lapid>ies f9d x !re=e possible to cut ! base ( ruby ?ick] ?an t ( sapphire1 & ?us keep ! weight great]4 ,x is in/ructive too :at c be done ) ! mo/ unpromis+ mat]ial by ! ex]cise ( a little +5uity4 ,?us ,ceylon sapphires are (t5 s irregul>ly col\r$ t consid]able skill is call$ = 9 cutt+ !m4 ,a /one may1 = in/ance1 be almo/ col\rless except = a s+le spot ( blue2 yet1 if ! /one be cut /eeply & ! spot be br\ght to ! base1 ! effect w be precisely ! same z if ! /one 7 uni=mly col\r$1 because all ! light em]g+ f ! /one has pass$ ?r\gh ! spot at ! base & !re=e be5 t9t$ blue4 ,! me*anism employ$ 9 ! fa%ion+ ( gem-/ones is simple 9 "*1 & comprises m]ely metal plates or :eels = slitt+1 & discs or laps = gr9d+ & poli%+ ! /ones1 ! =m] be+ set v]tically & rotat$ ab\t horizontal sp9dles1 & ! latt] set horizontally & rotat$ ab\t v]tical sp9dles4 ,me*anical p[] is occasionally us$ = driv+ bo? k9ds ( app>atus1 b g5]ally1 especially 9 slitt+ & 9 delicate "w1 h&-p[] is pref]r$4 ,9 ! ,ea/ native lapid>ies make use ( v]tical :eels 7,plate ,,xiii7 also = gr9d+ & poli%+ /ones1 :i* expla9s :y native-cut /ones nev] h truly plane facets2 x w be notic$ f ! picture t a long b[ is us$ to drive ! sp9dle4 ,ow+ to ! unique h>dness ( diamond x c be fa%ion$ only by ! aid ( its own p[d]4 ,! process diff]s !re=e mat]ially f ! cutt+ ( ! rema9+ gem-/ones1 & w be describ$ sep>ately4 ,inde$1 s diff]5t are ! two classes ( "w t firms seldom habitually und]take bo?4 ,! discov]y ( ! excell5t cleavage ( diamond enorm\sly r$uc$ ! lab\r ( cutt+ l>ge /ones4 ,a /one conta9+ a bad flaw may be split to conv5i5t %ape 9 z _m m9utes z ! days or ev5 weeks requir$ to gr9d x d[n4 ,! improvem5t 9 ! appliances & ! provision ( ample me*anical p[] has fur!r accel]at$ ! process & r$uc$ ! co/4 ,two ye>s 7 occupi$ 9 cutt+ ! diamond kn[n z ! ,pitt or ,reg5t1 :]eas 9 only six mon?s ! colossal ,cull9an 0 %ap$ into two l>ge & ov] a hundr$ small] /ones ) f> less loss ( mat]ial4 ,al?\gh ! brilliant =m 0 d]iv$ f ! regul> octah$ron1 x by no means foll[s t1 because diamond c be cleav$ to ! latt] =m1 su* is ! initial /ep 9 fa%ion+ ! r\gh mass4 ,! aim ( ! lapid>y is to cut ! l>ge/ possible /one f ! giv5 piece ( r\gh1 & ! f9i%$ brilliant usually be>s no relation :atev] to ! natural octah$ron4 ,! cleavage is utiliz$ only to free ! r\gh ( an awkw>d & useless excresc5ce1 or ( flaws4 ,al?\gh ! octah$ron is "o ( ! common =ms 9 :i* diamond is f\nd1 x is r>ely regul>1 & (t5] ?an n "o ( ! l>g] faces is made ! table4 ,! old me?od1 :i* is /ill 9 use1 = r\ghly fa%ion+ diamonds is t kn[n z brut+1 f ! ,fr5* ^w1 brutage1 = ! process1 or z %ap+4 ,two /ones ( ab\t ! same size are select$1 & are firmly atta*$ by means ( a h>d cem5t to ! ends ( two hold]s1 :i* are held "o 9 ea* h&1 & rubb$ h>d1 "o aga9/ ! o!r1 until surfaces ( ! requisite size are develop$ on ea* /one4 ,dur+ ! process ! /ones are held ov] a small box1 :i* cat*es ! preci\s p[d]4 ,a f9e sieve at ! bottom ( ! box all[s ! p[d] to fall ?r\gh into a tray und]nea?1 b holds back any?+ l>g]4 ,by means ( two v]tical p9s plac$ "o on ea* side ( ! box ! hold]s are reta9$ m easily 9 ! desir$ position1 & ! "w is ?r[n ma9ly on ! ?umbs4 ,?is "w cont9u$ day aft] day has a v disfigur+ effect ^u ! h&s despite ! ?ick gloves t are worn to protect !m2 ! sk9 ( ! ?umbs gr[s h>d & horny1 & ! fir/ & second f+]s become swoll5 & di/ort$4 ,:5 ! surfaces h ?us be5 =m$1 ! /one is h&$ to ! poli%]1 :o works !m into ! correct %ape & aft]w>ds poli%es !m1 ! /one pass+ backw>ds & =w>ds sev]al times betwe5 ! cutt] & ! poli%]4 ,! table1 f\r templets1 culet & f\r pavilions are fir/ =m$ & poli%$1 s t ! table has a squ>e %ape4 ,next ! quo9s are develop$ & poli%$1 & f9ally ! small facets are poli%$ on1 n be+ %ap$ fir/4 ,9 mod]n practice ! process ( brut+ has be5 modifi$ 9 "s cases by ! introduction ( ma*9]y1 & ! facets are gr\nd on1 ) consid]able improvem5t 9 ! regul>ity ( _! size & disposition1 & r$uction 9 ! am\nt ( poli%+ requir$4 ,moreov]1 to obviate ! loss ( mat]ial result+ f cont9u$ gr9d+1 l>ge /ones are fir/ slic$ by means ( rapidly-revolv+ copp] :eels *>g$ ) diamond p[d]4 ,! laps us$ = poli%+ diamonds are made ( a p>ticul> k9d ( s(t iron1 :i* is f\nd to surpass any o!r metal 9 reta9+ ! diamond p[d]4 ,!y are rotat$ at a high rate ( spe$1 :i* is ab\t #bjjj to #bejj revolutions a m9ute1 & ! heat develop$ by ! friction at ?is spe$ is too great = a cem5t to be us$2 a sold] or fusible alloy1 compos$ ( "o "p t9 to ?ree p>ts lead1 !re=e takes its place4 ,! sold] is held 9 a holl[ cup ( brass :i* is f its %ape call$ a #8dop1' an old ,dut* ^w mean+ %ell4 ,its ext]nal diamet] is ord9>ily ab\t #a 94 7#d cm471 b l>g] dops are1 ( c\rse1 us$ = l>ge /ones4 ,a /\t copp] /alk is atta*$ to ! bottom ( ! dop2 x is visible 9 ! view ( ! dop %[n at e on ,plate ,,vi1 & two slabs ( sold] are se5 ly+ 9 front ( ! dop4 ,! dop conta9+ ! sold] is plac$ 9 ! mid/ ( a non-lum9\s flame & heat$ until ! sold] s(t5s1 :5 x is remov$ by means ( ! small tongs1 c1 & plac$ upright on a /& su* z t %[n at a4 ,! long tongs1 d1 are us$ = %ap+ ! sold] into a cone at ! apex ( :i* ! diamond is plac$4 ,! sold] is work$ well ov] ! /one s t only ! "p to und]go poli%+ is expos$4 ,a diamond 9 position is %[n at f4 ,! top ( ! /& is sauc]-%ap$ to cat* ! /one %\ld x accid5tally fall (f ! dop1 & to prev5t pieces ( sold] fall+ on ! h&4 ,:ile /ill hot1 ! dop ) ! diamond 9 position on ! sold] is plung$ into cold wat] 9 ord] to cool x4 ,! fact t ! /one )/&s ?is dra/ic treatm5t is eloqu5t te/imony to its good !rmal conductivity2 o!r gem-/ones w\ld promptly split into fragm5ts4 ,x may be rem>k$ t s high is ! temp]ature at :i* diamond burns t x may be plac$ 9 ! gas flame )\t any fe> ( unt[>d results4 ,! dop is n[ ready = atta*m5t to an arm su* z t %[n at b2 ! /alk ( ! dop is plac$ 9 a groove runn+ across ! split end ( ! arm1 & is gripp$ tight by means ( a screw work$ by ! nut :i* is visible 9 ! picture4 ,illu/ration3 ,,plate ,,vi ,,appliances ,,us$ ,,= ,,poli%+ ,,diamonds4 ,illu/ration3 ,,plate ,,vii ,,poli%+ ,,diamonds ,f\r su* arms1 ea* ) a dop1 are us$ ) ! poli%+ lap 7,plate ,,vii71 & ea* /&s on two squ>e legs on ! b5*4 ,p9s1 p1 9 pairs are fix$ to ! b5* to prev5t ! arms be+ c>ri$ r\nd by ! friction2 "o ne> ! lap holds ! arm n f> f ! dop1 & ! o!r engages 9 a /rong metal tongue1 :i* is be/ se5 at ! end ( ! arm b on ,plate ,,vi4 ,?\gh ! arm1 :i* is made ( iron1 is heavy1 yet = poli%+ purposes x is insuffici5t1 & additional lead weights are laid on ! top ( x1 z 9 ! case ( ! arm at ! back on ,plate ,,vii4 ,! copp] /alk is /rong1 yet flexible1 & c be b5t to suit ! position ( ! facet to be poli%$2 on ,plate ,,vii ! dops a & b are upright1 b ! o!r two are incl9$4 ,9 addition to ! p[d] result+ f brut+1 bo>t1 i4e4 diamonds useless = cutt+1 are cru%$ up to supply poli%+ mat]ial1 & a little olive oil is us$ z a lubricant4 ,ow+ to ! friction s mu* heat is develop$ t ev5 ! sold] w\ld s(t5 aft] a "t1 & !re=e1 z a precaution1 ! dop is f "t to "t cool$ by imm]sion 9 wat]4 ,! /one has con/antly to be re-set1 ab\t six be+ ! maximum ev5 ( ! t9y facets ne> ! girdle t c be dealt ) by v>y+ ! incl9ation ( ! dop4 ,z ! "w approa*es completion ! /one is frequ5tly inspect$1 le/ ! poli%+ be c>ri$ too f> = ! developm5t ( ! prop] am\nt ( #8fire4' ,:5 f9i%$1 ! /ones are boil$ 9 sulphuric acid to remove all traces ( oil & dirt4 ,! :ole op]ation is evid5tly r\gh & ready 9 ! extreme2 b su* amaz+ skill d ! lapid>ies acquire1 t ev5 ! mo/ c>eful inspection by eye alone w\ld sc>ce detect any want ( prop] symmetry 9 a well-cut /one4 ,! fa%ion+ ( col\r$ /ones1 z all ! gem-/ones ap>t f diamond are t]m$ 9 ! jewell]y trade1 is on acc\nt ( _! inf]ior h>dness a f> less t$i\s op]ation4 ,!y are easily slit1 = :i* purpose a v]tical :eel 7,plate ,,viii7 made ( s(t iron is us$2 x is *>g$ ) diamond du/ & lubricat$ ) oil1 g5]ally p>aff94 ,:5 slit to ! desir$ size1 ! /one is atta*$ to a conv5i5tly %ap$ hold] by means ( a cem5t1 ! consi/5cy ( :i* v>ies ) ! h>dness ( ! /one4 ,x is set 9 ! cem5t 9 su* a way t ! plane desir$ = ! table facet is at "r angles to ! l5g? ( ! hold]1 & ! :ole ( ! upp] "p or cr[n is f9i%$ be=e ! /one is remov$ f ! cem5t4 ,! l[] half or base is treat$ 9 a simil> mann]4 ,?us 9 ! process ( gr9d+ & poli%+ ! /one is only once re-set2 z 0 /at$ above1 diamond dem&s v diff]5t treatm5t4 ,aga91 all col\r$ /ones are gr\nd d[n )\t any int]m$iate op]ation correspond+ to brut+4 ,! hold] is m]ely held 9 ! h&1 b to ma9ta9 its position m exactly its o!r end1 :i* is po9t$1 is ins]t$ 9 "o ( ! holes t are pi]c$ at int]vals 9 a v]tical sp9dle plac$ at a conv5i5t di/ance f ! lap 7,plate ,,viii71 :i* "o dep5d+ ^u ! incl9ation ( ! facet to be =m$4 ,= h>d /ones1 su* z ruby & sapphire1 diamond p[d] is g5]ally us$ z ! abrasive ag5t1 :ile = ! s(t] /ones em]y1 ! impure corundum1 is select$2 9 rec5t ye>s ! artificially prep>$ c>borundum1 silicide ( c>bon correspond+ to ! =mula ,c,si1 :i* is h>d] ?an corundum1 has come into vogue = gr9d+ purposes1 b x is un=tunately useless = slitt+1 because x refuses to cl+ to ! :eel4 ,to efface ! scrat*es left by ! abrasive ag5t & to imp>t a brilliant poli% to ! facets1 mat]ial ( less h>dness1 su* z putty-p[d]1 pumice1 or r\ge1 is employ$2 9 all cases ! lubricant is wat]4 ,! gr9d+ laps are made ( copp]1 gun-metal1 or lead2 & pewt] or wood5 laps1 ! latt] sometimes fac$ ) clo? or lea!r1 are us$ = poli%+4 ,z a g5]al rule1 ! h>d] ! /one ! great] ! spe$ ( ! lap4 ,illu/ration3 ,,plate ,,viii ,,slitt+ ,,col\r$ ,,/ones ,,poli%+ ,,col\r$ ,,/ones ,illu/ration3 ,,plate ,,ix ,,facet+ ,,ma*9e ,z 9 ! case ( diamond1 ! lapid>y judges ( ! position ( ! facet entirely by eye & t\*1 b a skill$ workman c develop a facet v close to ! !oretical position4 ,dur+ rec5t ye>s v>i\s devices h be5 inv5t$ to enable him to d 8 "w ) great] facility4 ,a ma*9e ( ?is k9d is illu/rat$ on ,plate ,,ix4 ,! /one is atta*$ by means ( cem5t to ! blunt end1 d1 ( ! hold]1 b1 :i* is ( ! cu/om>y k9d1 :ile ! o!r end is ins]t$ 9 a hole 9 a wood5 piece1 a1 :i* is adju/able 9 height by means ( ! screw above x4 ,! azimu?al positions ( ! facets are arrang$ by means ( ! octagonal coll>1 c1 ! sides ( :i* are held successively 9 turn aga9/ ! guide1 e4 ,! /& itself is clamp$ to ! b5*4 ,! ma*9e is1 h[ev]1 little us$ except = *eap /ones1 because x is too accurate & leads to wa/e ( mat]ial4 ,/ones are sold by weight1 & s long z ! eye is satisfi$1 no attempt is made to atta9 to absolute symmetry ( %ape4 ,! pictures on ,plates ,x-,,xiii illu/rate lapid>ies' work%ops 9 v>i\s p>ts ( ! _w4 ,! fir/ two %[ an (fice & a work%op situat$ 9 ,hatton ,g>d51 ,london2 9 ! =m] c]ta9 ( ! /aff are select+ f ! p>cels /ones suitable = cutt+4 ,! ?ird depicts a m primitive e/abli%m5t at ,ekat]9burg 9 ! ,urals4 ,! f\r? %[s a typical ,fr5* family--pre1 mre1 et fils--9 ! ,jura di/rict1 all busily engag$2 on ! table w be notic$ a facet+ ma*9e ( ! k9d describ$ above4 ,9 ! fif? picture a native lapid>y 9 ,calcutta is se5 at "w ) ! driv+ b[ 9 8 "r1 & ! /one 9 8 left1 h&4 ,a curi\s diff]5ce exi/s 9 ! sy/ems ( *>g+ = cutt+ diamonds & col\r$ /ones4 ,! co/ ( cutt+ ! latt] is reckon$ by ! weight ( ! f9i%$ /one1 ! rate v>y+ f #as4 to #hs4 a c>at accord+ to ! "* ( ! /one & ! difficulty ( ! "w2 :ile 9 ! case ( diamonds1 on ! o!r h&1 ! weight ( ! r\gh mat]ial det]m9es ! co/1 ! rate be+ ab\t #ajs4 to #djs4 a c>at accord+ to ! size1 :i* on ! av]age is equival5t to ab\t #cjs4 to #abjs4 a c>at calculat$ on ! weight ( ! f9i%$ /one4 ,! reason ( ! di/9ction is obvi\sly because ! prop] proportions 9 a brilliant-cut diamond mu/ be ma9ta9$1 :atev] be ! loss 9 weight involv$2 9 col\r$ /ones ! %ape is n ( su* prim>y importance4 ,illu/ration3 ,,plate ,x ,,lapid>y',s ,,work%op ,,& ,,(fice ,,9 ,,engl& ,illu/ration3 ,,plate ,,xi ,,lapid>y',s ,,work%op ,,9 ,,russia ,:5 f9i%$1 ! /one f9ds its way ) o!rs ak9 to x to ! manufactur+ jewell]'s e/abli%m5t1 :]e x is h&$ to ! sett]1 :o m\nts x 9 a r+1 necklace1 broo*1 or :atev] article ( jewell]y x is int5d$ =4 ,! metal us$ 9 ! gr\ndwork ( ! sett+ is g5]ally gold1 b plat9um is also employ$ :]e an unobtrusive & unt>ni%able metal is dem&$1 & silv] f9ds a place 9 *eap] jewell]y1 al?\gh x is s]i\sly h&icapp$ by its susceptibility to ! black5+ influ5ce ( ! sulphur\s fumes pres5t 9 ! smoke-lad5 atmosph]e ( t[ns4 ,! /one may be ei!r emb$d$ 9 ! metal or held by claws4 ,! =m] is by f> ! saf]1 b ! latt] ! m elegant1 & x has ! advantage ( expos+ ! /one j\r1 to use ! ,fr5* jewell]s' expression1 s t its g5u95ess is m evid5tly te/ifi$4 ,x is v important t ! claw sett+ be p]iodically exam9$1 le/ ! own] "o day exp]i5ce ! mortification ( f9d+ t a valuable /one has dropp$ out2 gold1 ow+ to its s(tness1 we>s away 9 c\rse ( "t4 ,up to q rec5t ye>s mod]n jewell]y 0 ju/ly op5 to ! criticism t x 0 lack+ 9 v>iety1 t little attempt 0 made to secure h>moni\s association 9 ei!r ! col\r or ! lu/re ( ! gem-/ones1 & t ! glitt] ( ! gold m\nt 0 frequ5tly f> too obtrusive4 ,gold consorts admirably ) ! ri* gl[ ( ruby1 b is q unsuit$ to ! gleam+ fire ( a brilliant4 ,:]e ! metal is pres5t m]ely = ! me*anical purpose ( hold+ ! /ones 9 position1 x %\ld be made z little noticeable z possible4 ,! arti/ic treatm5t ( jewell]y is1 h[ev]1 receiv+ n[ adequate att5tion 9 ! be/ ,p>is & ,london h\ses4 ,"s rec5t designs are illu/rat$ on ,plates ,,iv & ,v4 ,illu/ration3 ,,plate ,,xii ,,fr5* ,,family ,,cutt+ ,,/ones ,illu/ration3 ,,plate ,,xiii ,,indian ,,lapid>y ,,*apt] ,,xiii ,,nom5clature ,,( ,,preci\s ,,/ones ,! names 9 popul> use = ! pr9cipal gem-/ones may be trac$ back to v e>ly times1 &1 s9ce !y 7 appli$ long be=e ! det]m9ative /udy ( m9]als _h become a sci5ce1 _! significance has v>i$ at diff]5t dates1 & is ev5 n[ f> f precise4 ,no ambiguity or confusion c\ld arise if jewell]s made use ( ! sci5tific names = ! species1 b mo/ ( !m are unkn[n or at lea/ unfamili> to ^? unv]s$ 9 m9]alogy1 & to bani% old-e/abli%$ names is undesirable1 ev5 if ! task 7 n hopeless4 ,! "n select$ = a gem-/one may h a v important be>+ on its =tunes4 ,:5 ! love-sick ,juliet qu]i$ #8,:at's 9 a "n8' h] m9d 0 w&]+ f> f jewels2 = !m a "n is ev]y?+4 ,! beautiful r$ /ones t accompany ! diamond 9 ,s\? ,africa 7 almo/ a drug 9 ! m>ket "u _! prop] title--g>net1 b comm& a ready sale "u ! misnom] #8,cape-ruby4' ,to _m m9ds !re is a subtle satisfaction 9 ! possession ( a /one :i* is assum$ to be a sort ( ruby t w\ld be de/roy$ by ! k t ! /one really belong$ to ! c9d]ella species ( gem-/ones--! despis$ g>net4 ,= simil> reasons x 0 deem$ advisable to (f] ! lu/r\s gre5 g>net f\nd "s ?irty & odd ye>s ago 9 ! ,ural ,m\nta9s z #8oliv9e1' n a happy *oice s9ce _! col\r is grass- r ?an olive-gre51 ap>t f ! fact t ! t]m is 9 g5]al use 9 sci5ce = ! species kn[n 9 jewell]y z p]idot4 ,! names employ$ 9 jewell]y are l>gely bas$ ^u ! col\r1 ! lea/ reliable f a det]m9ative po9t ( view ( all ! physical *>act]s ( gem-/ones4 ,qualify+ t]ms are employ$ to di/+ui% /ones ( obvi\sly diff]5t h>dness4 #8,ori5tal' di/+ui%es v>ieties ( corundum1 b does n imply t !y necess>ily came f ! ,ea/2 ! f9e/ gem-/ones orig9ally rea*$ ,europe by t road1 & ! h>de/ col\r$ /ones consequ5tly receiv$ t t]m ( di/9ction4 ,ne>ly all r$ /ones are gr\p$ "u ! "n ruby1 :i* is d]iv$ f a ,lat9 ^w1 rub]1 mean+ r$1 or "u o!r names adapt$ f x1 su* z rubellite1 rubicelle4 ,x is prop]ly appli$ to r$ corundum2 #8balas' ruby is sp9el1 :i* is associat$ ) ! true ruby at ! ,burma m9es & is simil> 9 appe>ance to x :5 cut1 & #8,cape' ruby1 is1 z has be5 /at$ above1 a g>net f ,s\? ,africa4 ,rubellite is ! lovely rose-p9k t\rmal9e1 f9e examples ( :i* h rec5tly be5 discov]$ 9 ,cali=nia1 & rubicelle is a less pron\nc$ly r$ sp9el4 ,sapphire is by f> ! olde/ & "o ( ! mo/ int]e/+ ( ! words us$ 9 ! language ( jewels4 ,x occurs 9 ,hebrew & ,p]sian1 anci5t tongues1 & means blue4 ,x 0 app>5tly employ$ = lapis lazuli or simil> sub/ance1 b 0 transf]r$ to ! blue corundum ^u ! discov]y ( ?is spl5did /one4 ,oblivi\s ( ! real mean+ ( ! ^w1 jewell]s apply x 9 a quasi-g5]ic s5se to all ! v>ieties ( corundum ) ! exception ( ! r$ ruby1 & give v5t to su* incongru\s expressions z #8:ite sapphire1' #8yell[ sapphire'2 x is true su* /ones (t5 conta9 traces ( blue col\r1 b t is n ! reason ( ! t]ms4 #8,brazilian' sapphire is blue t\rmal9e1 a some:at r>e t9t = ?is species4 ,! curi\s hi/ory ( ! ^w topaz w be f\nd bel[ 9 ! *apt] deal+ ) ! species ( t "n4 ,x has always d5ot$ a yell[ /one1 & at ! pres5t day is appli$ by jewell]s indiscrim9ately to ! true topaz & citr9e1 ! yell[ qu>tz1 ! =m]1 h[ev]1 be+ sometimes di/+ui%$ by ! prefix #8,brazilian4' #8,ori5tal' topaz is corundum1 & #8occid5tal' topaz is a t]m occasionally employ$ = ! yell[ qu>tz4 ,em]ald1 :i* means gre51 0 fir/ us$ = *rysocolla1 an opaque gre5i% /one 7p4 #bhh71 b 0 aft]w>ds appli$ to ! priceless gre5 v>iety ( b]yl1 = :i* x is /ill reta9$4 #8,ori5tal' em]ald is corundum1 #8,brazilian' em]ald 9 ! eighte5? c5tury 0 a common t]m = ! gre5 t\rmal9e rec5tly introduc$ to ,europe1 & #8,uralian' em]ald has be5 t5tatively sugge/$ = ! gre5 g>net m usually kn[n z #8oliv9e4' ,ame?y/ is prop]ly ! violet qu>tz1 b ) ! prefix #8ori5tal' x is also appli$ to violet corundum1 ?\gh "s jewell]s use x = ! brilliant qu>tz1 ) purple & :ite sectors1 f ,sib]ia4 ,alm&9e1 :i* is d]iv$ f ! "n ( an ,ea/]n m>t = preci\s /ones1 has come to signify a /one ( columb9e-r$ hue1 pr9cipally g>net1 b ) suitable qualification corundum & sp9el also4 ,! nom5clature ( jewell]y t5ds to sugge/ relations betwe5 ! gem-/ones = :i* !re is no real f\ndation1 & to obscure ! ess5tial id5tity1 except f ! po9t ( view ( col\r1 ( sapphire & ruby1 em]ald & aquam>9e1 cairngorm & ame?y/4 ,,*apt] ,,xiv ,,manufactur$ ,,/ones ,! initial /ep 9 ! exam9ation ( a cry/alliz$ sub/ance is to det]m9e its physical *>act]s & to resolve x by *emical analysis into its compon5t elem5ts2 ! f9al1 & by f> ! h>de/1 /ep is to build x up or syn!tically prep>e x f its con/itu5ts4 ,unkn[n to ! _w at l>ge1 "w ( ! latt] k9d has long be5 go+ on )9 ! walls ( laboratories1 & z ! advance 9 k plac$ 9 ! h&s ( exp]im5t]s weapons m & m comp>able ) ^? wield$ by nature1 _! ef=ts h be5 increas+ly successful4 ,s /up5d\s1 h[ev]1 are ! p[]s ( nature t ! possibility ( reproduc+1 by human ag5cy1 ! treasur$ /ones :i* are extract$ f ! e>? 9 v>i\s p>ts ( ! globe at ! co/ ( inf9ite toil & lab\r has always be5 d]id$ by ^? ignorant ( :at _h already be5 accompli%$4 ,great1 !re=e1 0 ! con/]nation & ! turmoil :5 concrete evid5ce t c\ld n be ga9said %[$ t man's re/less ef=ts to bridle nature to 8 w 7 n 9 va91 & congresses ( all ! high-prie/s ( jewell]y 7 ha/ily conv5$ to ban su* unrighte\s products1 ) :at ultimate success rema9s to be se54 ,cry/allization may be caus$ 9 f\r diff]5t ways1 ( :i* ! second alone has z yet yield$ /ones l>ge en\gh to be cut-- #a4 ,by ! sep>ation ( ! sub/ance f a saturat$ solution4 ,9 nature ! solv5t may n be m]ely hot wat]1 or wat] *>g$ ) an acid1 b molt5 rock1 & ! temp]ature & ! pressure may be excessively high4 #b4 ,by ! solidification ( ! liquefi$ sub/ance ^u cool+4 ,ice is a famili> example ( ?is type4 #c4 ,by ! sublimation ( ! vap\r ( ! sub/ance1 :i* means ! direct passage f ! vap\r to ! solid /ate )\t trav]s+ ! usually int]v5+ liquid /ate4 ,x is usually ! mo/ difficult ( atta9m5t ( ! f\r me?ods2 ! mo/ famili> in/ance is sn[4 #d4 ,by ! precipitation ( ! sub/ance f a solution :5 set free by *emical action4 ,o!r ?+s be+ equal1 ! simpl] ! composition ! great] is ! ease ) :i* a sub/ance may be expect$ to be =m$2 =1 in/ead ( "o complex sub/ance1 two or m diff]5t sub/ances may evolve1 unless ! conditions are nicely arrang$4 ,attempts1 = in/ance1 to produce b]yl might result in/ead 9 a mixture ( *rysob]yl1 ph5akite1 & qu>tz4 ,by f> ! simple/ 9 composition ( all ! preci\s /ones is diamond1 :i* is pure cry/alliz$ c>bon2 b its manufacture is att5d$ by well-nigh insup]able difficulties4 ,if c>bon be heat$ 9 air1 x burns at a temp]ature well bel[ its melt+ po9t2 moreov]1 unless an enorm\sly high pressure is simultane\sly appli$1 ! product is ! o!r =m ( cry/alliz$ c>bon1 namely1 ! comp>atively wor?less graphite4 ,moissan's int]e/+ c\rse ( exp]im5ts 7 9 "s degree successful1 b ! t9y diamonds 7 wor?less z jewels1 & ! exp5se involv$ 9 _! manufacture 0 out ( all proportion to any possible comm]cial value !y might h4 ,next to diamond ! simple/ sub/ances among preci\s /ones are qu>tz 7cry/alliz$ silica7 & corundum 7cry/alliz$ alum9a74 ,! cry/allization ( silica has be5 effect$ 9 sev]al ways1 b ! value 9 jewell]y ( qu>tz1 ev5 ( ! violet v>iety1 ame?y/1 is n su* z to w>rant its manufacture on a comm]cial scale4 ,corundum1 on ! o!r h&1 is held 9 high e/eem2 rubies & sapphires1 ( good col\r & free f flaws1 h always comm&$ good prices4 ,! "q ( _! production by artificial means has !re=e m ?an academic int]e/4 ,ev] s9ce ! ye> #ahcg1 :5 ,gaud9 produc$ a few t9y flakes1 ,fr5* exp]im5t]s h /eadily prosecut$ _! rese>*es 9 ! cry/allization ( corundum4 ,frmy & ,feil1 9 #ahgg1 7 ! fir/ to meet ) mu* success4 ,a portion ( "o ( _! crucibles l9$ ) gli/5+ ruby flakes is exhibit$ 9 ! ,briti% ,museum 7,natural ,hi/ory74 ,illu/ration3 ,,fig4 #ec4--,v]neuil's ,inv]t$ ,bl[pipe4 ,9 #ahhe ! jewell]y m>ket 0 completely tak5 by surprise by ! appe>ance ( r$ /ones1 emanat+1 s x is alleg$1 f ,g5eva2 hav+ ! physical *>act]s ( g5u9e rubies1 !y 7 accept$ z1 & comm&$ ! prices (1 ! natural /ones4 ,x 0 ev5tually discov]$ t !y _h result$ f ! fusion ( a numb] ( fragm5ts ( natural rubies 9 ! oxy-hydrog5 flame4 ,! orig9al col\r 0 driv5 (f at t high temp]ature1 b 0 reviv$ by ! previ\s addition ( a little bi*romate ( potassium4 ,ow+ to ! inequalities ( gr[?1 ! cracks due to rapid cool+1 ! inclusion ( air-bubbles1 (t5 s num]\s z to cause a cl\dy appe>ance1 &1 above all1 ! unnatural col\r1 ^! recon/ruct$ /ones1 z !y are t]m$1 7 f> f satisfactory1 b yet !y m>k$ su* an advance on any?+ t _h be5 accompli%$ be=e t = "s "t no suspicion 0 ar\s$ z to _! be+ o!r ?an natural /ones4 ,a notable advance 9 ! syn!sis ( corundum1 p>ticul>ly ( ruby1 0 made 9 #aijd1 :5 ,v]neuil1 :o _h s]v$ 8 appr5tice%ip to sci5ce "u ! guidance ( ,frmy1 inv5t$ 8 +5i\s inv]t$ =m ( bl[pipe 7,fig4 #ec71 :i* enabl$ him to ov]come ! difficulties t _h baffl$ e>li] inve/igators1 & to manufacture rubies vy+ 9 appe>ance aft] cutt+ ) ! be/ ( nature's productions4 ,! bl[pipe consi/$ ( two tubes1 ( :i* ! upp]1 ,e1 wide above1 0 con/rict$ bel[1 & pass+ d[n ! c5tre ( ! l[]1 ,f1 t]m9at$ j above ! orifice ( ! latt] 9 a f9e nozzle4 ,oxyg5 0 admitt$ at ,c ?r\gh ! plate cov]+ ! upp] end ( ! tube1 ,e4 ,a rod1 :i* pass$ ?r\gh a rubb] coll> 9 ! same plate1 support$ inside ! tube1 ,e1 a vessel1 ,d1 & at ! upp] end t]m9at$ 9 a small plate1 on :i* 0 fix$ a disc1 ,b4 ,! hamm]1 ,a1 :5 lift$ by ! action ( an electromagnet & releas$1 fell by gravity & /ruck ! disc4 ,! latt] c\ld be turn$ ab\t a horizontal axis plac$ ecc5trically1 s t ! height ?r\gh :i* ! hamm] fell & ! consequ5t =ce ( ! bl[ c\ld be regulat$4 ,! rubb] coll>1 :i* 0 p]fectly gas-tight1 held ! rod securely1 b all[$ ! %ocks to be transmitt$ to ! vessel1 ,d1 an arrangem5t ( guides ma9ta9+ ! slight motion ( ! vessel /rictly v]tical4 ,?is vessel1 :i* c>ri$ ! alum9a p[d] us$ 9 ! manufacture ( ! /one1 _h z its base a cyl9drical sieve ( f9e me%4 ,! succession ( rapid taps ( ! hamm] caus$ a regul> fe$ ( p[d] d[n ! tube1 ! am\nt be+ regulat$ by v>y+ ! height ?r\gh :i* ! hamm] fell4 ,hydrog5 or coal-gas 0 admitt$ at ,g into ! out] tube1 ,f1 & 9 ! usual way met ! oxyg5 j above ! orifice1 ,l4 ,to exclude irregul> draughts1 ! flame 0 surr\nd$ by a scre51 ,m1 :i* 0 provid$ ) a mica w9d[1 & a wat]-jacket1 ,k1 protect$ ! upp] "p ( ! app>atus f excessive heat+4 ,illu/ration3 ,,fig4 #ed4--#8;,b\le1' or ,pe>-%ap$ ,drop4 ,! alum9a 0 precipitat$ f a solution ( pure ammonia--alum1 7,,nh#d7b,,s#d4;,al#b7,,s#d7c4bd;,h#b,o1 9 di/ill$ wat] by ! addition ( pure ammonia1 suffici5t *rome-alum also be+ dissolv$ ) ! ammonia-alum to furni% ab\t #b p] c5t4 ( *romic oxide 9 ! result+ /one4 ,! p[d]1 c>efully prep>$ & purifi$1 0 plac$1 z has be5 /at$ above1 9 ! vessel1 ,d1 & on rea*+ ! flame at ! orifice x melt$1 & fell z a liquid drop1 ,n1 ^u ! p$e/al1 ,p1 :i* 0 =m$ ( previ\sly fus$ alum9a4 ,?is p$e/al 0 atta*$ by a plat9um sleeve to an iron rod1 ,q1 :i* 0 provid$ ) ! necess>y screw adju/m5ts1 ,r & ,s1 = c5tr+ & l[]+ x z ! drop grew 9 size4 ,great c>e 0 ex]cis$ to free ! p[d] f any trace ( potassium1 :i*1 if pres5t1 imp>t$ a br[ni% t+e to ! /one4 ,! pressure ( ! oxyg51 l[ initially bo? to prev5t ! p$e/al f melt+1 & to keep ! area ( ! drop 9 contact ) ! p$e/al z small z possible1 because o!rwise flaws t5d$ to />t on cool+1 0 gradually increas$ until ! flame rea*$ ! critical temp]ature :i* kept ! top ( ! drop melt$1 b n boil+4 ,! supply ( p[d] 0 at ! same "t c>efully proportion$ to ! pressure4 ,! p$e/al1 ,p1 0 f "t to "t l[]$1 & ! drop grew 9 ! %ape ( a pe> 7,fig4 #ed71 ! apex ( :i* 0 d[nw>ds & adh]$ to ! p$e/al by a n>r[ /alk4 ,z soon z ! drop rea*$ ! maximum size possible ) ! size ( ! flame1 ! gases 7 %>ply & simultane\sly cut (f4 ,aft] t5 m9utes or s ! drop 0 l[]$ f ! *amb]1 ,m1 by ! screw1 ,s1 & :5 q cold 0 remov$ f ! p$e/al4 ,v few *anges h be5 made 9 ! me?od :5 adapt$ to comm]cial use4 ,coal-gas has1 h[ev]1 entirely replac$ ! co/ly hydrog51 & ! hamm] is op]at$ by a cam in/ead ( an electromagnet1 :ile1 z may be se5 f ! view ( a gem-/one factory 7,plate ,,xiv71 a numb] ( bl[pipes are plac$ 9 l9e s t _! cams are work$ by ! same %aft1 a4 ,! fire-clay scre51 b1 surr\nd+ ! flame is = conv5i5ce ( removal divid$ into halves longitud9ally1 & a small hole is left 9 front = view+ ! /one dur+ gr[?1 a r$ glass scre51 c1 be+ provid$ 9 front to protect ! eyes f ! int5se gl>e4 ,half ! fire-clay scre5 ( ! bl[pipe 9 ! c5tre ( ! ,plate has be5 remov$ to %[ ! arrangem5t ( ! int]ior4 ,! c5tr+ & ! rais+ & l[]+ app>atus1 d1 h be5 modifi$4 ,! process is s simple t "o man c att5d to a doz5 or s ( ^! ma*9es1 & x takes only "o h\r to gr[ a drop l>ge en\gh to be cut into a t5-c>at /one4 ,illu/ration3 ,,plate ,,xiv ,,bl[pipe ,,us$ ,,= ,,! ,,manufacture ,,( ,,rubies ,,& ,,sapphires ,! drops1 unless ! f9i%$ /one is requir$ to h a simil> pe> %ape1 are divid$ longitud9ally ?r\gh ! c5tral core into halves1 :i* 9 bo? %ape & ori5tation are admirably suit$ to ! purposes ( cutt+2 z a g5]al rule1 ! drop splits dur+ cool+ into ! desir$ direction ( its own accord4 ,illu/ration3 ,,fig4 #ee4--;,bubbles & ,curv$ ,/ri 9 ,manufactur$ ,ruby4 ,ea* drop is a s+le cry/all9e individual1 & n1 z might h be5 anticipat$1 an alum9a glass or an irregul> aggregation ( cry/all9e fragm5ts1 &1 if ! drop has cool$ prop]ly1 ! cry/allographic axis is p>allel to ! core ( ! pe>4 ,! cut /one w !re=e h n only ! d5sity & h>dness1 b also all ! optical *>act]s--refractivity1 d\ble refraction1 di*roism1 etc4--p]ta9+ to ! natural species1 & w obey precisely ! same te/s ) ! refractomet] & ! di*roscope4 ,7 x n = c]ta9 imp]fections x w\ld be impossible to di/+ui% betwe5 ! /ones =m$ 9 ,nature's va/ work%op & ^? produc$ )9 ! conf9es ( a laboratory4 ,! artificial /ones1 h[ev]1 are r>ely1 if ev]1 free f m9ute air-bubbles 7,fig4 #ee71 :i* c easily be se5 ) an ord9>y l5s4 ,_! sph]ical %ape diff]5tiates !m f ! plane-sid$ cavities n infrequ5tly visible 9 a natural /one 7,fig4 #ef74 ,moreov]1 ! col\r+ matt] v>ies slightly1 b imp]ceptibly1 9 successive %ells1 & consequ5tly 9 ! f9i%$ /one a c>eful eye c disc]n ! curv$ /riations 7,fig4 #ee7 correspond+ 9 %ape to ! orig9al %ell4 ,9 a natural /one1 on ! o!r h&1 al?\gh zones ( diff]5t col\rs or v>y+ %ades are n uncommon1 ! result+ /riations are /raight 7,fig4 #ef71 correspond+ to ! plane faces ( ! orig9al cry/al =m4 ,by sacrific+ mat]ial x might be possible to cut a small /one free f bubbles1 b ! curv$ /riations w\ld always be pres5t to betray its orig94 ,illu/ration3 ,,fig4 #ef4--,m>k+s 9 ,natural ,ruby4 ,! success t att5d$ ! manufacture ( ruby enc\rag$ ef=ts to imp>t o!r t9ts to cry/alliz$ alum9a4 ,by r$uc+ ! p]c5tage am\nt ( *romic oxide1 p9k /ones 7 turn$ out1 9 col\r n unlike ^? ,brazilian topazes1 ! orig9al hue ( :i* has be5 alt]$ by ! application ( heat4 ,^! artificial /ones h !re=e be5 call$ #8sci5tific topaz'2 ( c\rse1 q wrongly1 s9ce topaz1 :i* is prop]ly a fluo-silicate ( alum9ium1 is q a diff]5t sub/ance4 ,e>ly attempts made to obta9 ! exquisite blue t9t ( ! true sapphire 7 fru/rat$ by an unexpect$ difficulty4 ,! col\r+ matt]1 cobalt oxide1 0 n diffus$ ev5ly ?r\gh ! drop1 b 0 huddl$ toge!r 9 splot*es1 & x 0 f\nd necess>y to add a consid]able am\nt ( magnesia z a flux be=e a uni=m di/ribution ( col\r c\ld be secur$4 ,x 0 !n discov]$ t1 despite ! col\r1 ! /ones _h ! physical *>act]s1 n ( sapphire1 b ( ! species closely alli$ to x1 namely1 sp9el1 alum9ate ( magnesium4 ,by an unsurpassable ef=t ( nom5clature ^! blue /ones 7 giv5 ! extraord9>y "n ( #8,hope sapphire1' f fanciful analogy ) ! fam\s blue diamond :i* 0 once ! pride ( ! ,hope collection4 ,a blue sp9el is occasionally f\nd 9 nature1 b ! actual t9t is some:at diff]5t4 ,^! manufactur$ /ones h ! disadvantage ( turn+ purple 9 artificial light4 ,by sub/itut+ lime = magnesia z a flux1 ,p>is1 a pupil ( ,v]neuil's1 produc$ blue /ones :i* 7 n affect$ to ! same ext5t4 ,! difficulty 0 at l5g? ov]come at ! close ( #aiji1 :5 ,v]neuil1 by employ+ z t9ctorial ag5ts #je p] c5t4 ( titanium oxide & #ae p] c5t4 ( magnetic iron oxide1 succe$$ 9 produc+ blue corundum2 x1 h[ev]1 _h n q ! t9t ( sapphire4 ,/ones subsequ5tly manufactur$1 :i* 7 bett] 9 col\r1 conta9$ ab\t #jab p] c5t4 ( titanium oxide1 b no iron at all4 ,by ! addition to ! alum9a ( a little nickel oxide & vanadium oxide respectively1 yell[ & yell[i% gre5 corundums h be5 obta9$4 ,! latt] h 9 artificial light a di/9ctly r$di% hue1 & h !re=e be5 t]m$ #8sci5tific alex&rite'2 ( c\rse1 q incorrectly1 s9ce ! true alex&rite is a v>iety ( *rysob]yl1 alum9ate ( b]yllium1 a v diff]5t sub/ance4 ,if no col\r+ matt] at all be add$ & ! alum be free f pota%1 col\rless /ones or :ite sapphires are =m$1 :i* pass "u ! "n #8sci5tific brilliant4' ,x is sc>cely necess>y to rem>k t !y are q di/9ct f ! true brilliant1 diamond4 ,! high prices comm&$ by em]alds1 & ! comp>ative success t att5d$ ! recon/ruction ( ruby f fragm5ts ( natural /ones1 sugge/$ t equal success might foll[ f a simil> process ) p[d]$ b]yl1 *romic oxide be+ us$ z ! col\r+ ag5t4 ,! result+ /ones are1 inde$1 a fair imitation1 be+ ev5 provid$ ) flaws1 b !y are a b]yl glass ) l[] specific gravity & refractivity ?an ! true b]yl1 & are wrongly t]m$ #8sci5tific em]ald4' ,moreov]1 rec5tly mo/ ( ! /ones s nam$ on ! m>ket are m]ely gre5 pa/e4 ,x is un=tunate t ! real success :i* has be5 a*iev$ 9 ! manufacture ( ruby & sapphire %\ld be obscur$ by ! ill-f\nd$ claims tacitly ass]t$ 9 o!r cases4 ,at ! "t ! manufactur$ ruby 0 a novelty x fet*$ z mu* z #f a c>at1 b z soon z x 0 discov]$ t x c\ld easily be diff]5tiat$ f ! natural /one1 a collapse took place1 & ! price fell abruptly to #cjs41 & ev5tually to #es4 & ev5 #as4 a c>at4 ,! sapphires run slightly high]1 f #bs4 to #gs4 a c>at4 ,! prices ( ! natural /ones1 :i* at fir/ _h fall51 h n[ ris5 to almo/ _! =m] level4 ,! extreme disp>ity at pres5t obta9+ betwe5 ! prices ( ! artificial & ! natural ruby r5d]s ! fraudul5t sub/itution ( ! "o = ! o!r a great temptation1 & x behoves pur*as]s to bew>e :]e & f :om !y buy1 & to be suspici\s ( app>5tly rem>kable b>ga9s1 especially at places l ,colombo & ,s+apore :]e t\ri/s ab\nd4 ,x is no secret t "s ?\s&s ( c>ats ( manufactur$ rubies are %ipp$ annually to ! ,ea/4 ,caveat emptor4 ,,*apt] ,,xv ,,imitation ,,/ones ,! b]yl glass m5tion$ 9 ! previ\s *apt] m>ks ! transition /age betwe5 manufactur$ /ones :i* 9 all ess5tial *>act]s are id5tical ) ^? f\nd 9 nature1 & artificial /ones :i* resemble ! correspond+ natural /one 9 outw>d appe>ance only4 ,9 a s5se bo? sorts may be /yl$ artificial1 b x w\ld be mislead+ to conf\nd !m "u ! same appellation4 ,common pa/e1#f :i* is met ) 9 drap]y goods & *eap ornam5ts 9 g5]al--hat-p9s1 buckles1 & s =?--is compos$ ( ord9>y cr[n-glass or fl9t-glass1 ! refractive indices be+ ab\t #aec & #afc respectively4 ,! f9e/ quality1 :i* is us$ = imitations ( brilliants1 is call$ #8/rass4' ,x is a d5se lead fl9t-glass ( high refraction & /rong col\r-disp]sion1 consi/+ ( #chb p] c5t4 ( silica1 #ecc r$ lead 7oxide ( lead71 & #gh potassium c>bonate1 ) small quantities ( soda1 alum9a1 & o!r sub/ances4 ,h[ admirable ^! imitations may be1 a /udy ( ! w9d[s ( a %op devot$ to su* ?+s w %[4 ,un=tunately ! addition ( lead1 :i* is necess>y = imp>t+ ! requisite refraction & #8fire' to ! /rass1 r5d]s ! /ones exce$+ly s(t4 ,all glass yields to ! file1 b /rass /ones are scrat*$ ev5 by ord9>y w9d[-glass4 ,if worn 9 su* a way t !y are rubb$1 !y spe$ily lose ! brilliance ( _! poli%1 &1 moreov]1 !y are susceptible to attack by ! sulphur\s fumes pres5t 9 ! smoky air ( t[ns1 & turn aft] a "t a dirty br[n 9 hue4 ,:5 col\r$ /ones are to be imitat$1 small quantities ( a suitable metallic oxide are fus$ ) ! glass2 cobalt gives rise to a royal-blue t9t1 *romium a ruby r$1 & manganese a violet4 ,common pa/e is n highly refractive en\gh to give satisfactory results :5 cut z a brilliant1 & ! bases are !re=e (t5 coat$ ) quicksilv]1 or1 9 ! case ( old jewell]y1 cov]$ ) foil 9 ! sett+1 9 ord] to secure m complete reflection f ! int]ior4 ,! fa%ion+ ( ^! imitation /ones is easy & *eap4 ,be+ m\ld$1 !y d n require cutt+1 & ! poli%+ ( ! facets ?us =m$ is soon done on acc\nt ( ! s(tness ( ! /ones4 ,a te/ ) a file readily diff]5tiates pa/e /ones f ! natural /ones !y pret5d to be4 ,be+ necess>ily s+ly refractive1 !y are1 ( c\rse1 lack+ 9 di*roism1 & _! refractivity seldom accords ev5 approximately ) t ( ! correspond+ natural /one4 ,9 ord] to meet ! te/ = h>dness ! d\blet 0 devis$4 ,su* a /one is compos$ ( two p>ts--! cr[n consi/+ ( col\rless qu>tz or o!r inexp5sive real & h>d /one1 & ! base be+ made up ( col\r$ glass4 ,:5 ! imitation1 say ( a sapphire1 is int5d$ to be m exact1 ! cr[n is made ( a real sapphire1 b "o defici5t 9 col\r1 ! requisite t9t be+ obta9$ f ! pa/e =m+ ! "u "p ( ! d\blet4 ,9 case ! base %\ld also be te/$ = h>dness ! triplet has be5 devis$4 ,9 ?is ! base is made ( a real /one also1 & ! col\r$ pa/e is conf9$ to ! girdle section1 :]e x is hidd5 by ! sett+4 ,sapphires & em]alds ( indiff]5t col\r are sometimes slit across ! girdle2 ! int]ior surfaces are poli%$1 & col\r+ matt] is introduc$ ) ! cem5t1 g5]ally ,canada balsam1 :i* is us$ to re-unite ! two portions ( ! /one toge!r4 ,all su* imitations may be detect$ by plac+ ! /one 9 oil1 :5 ! surfaces sep>at+ ! portions ( ! composite /one w be visible1 or ! b9d+ cem5t may be dissolv$ by imm]s+ ! /one1 if unm\nt$1 9 boil+ wat]1 or 9 alcohol or *lor(orm1 :5 ! /one w fall to pieces4 ,! glass imitations ( pe>ls1 :i* h become v common 9 rec5t ye>s1 may1 ap>t f _! inf]ior iridesc5ce1 be detect$ by _! great] h>dness1 or by ! app>5t d\bl+ (1 say1 a spot ( ink plac$ on ! surface1 ow+ to reflection f ! inn] surface ( ! glass %ell4 ,!y are made ( small holl[ sph]es =m$ by bl[+4 ,next to ! glass comes a l9+ ( p>*m5t size1 & next ! "u l9+1 :i* is ! mo/ important "p ( ! imitation1 consi/+ ( a prep>ation ( fi% scales call$ ,ess5ce d',ori5t1 ,:5 ! l9+ is dry1 ! globe is fill$ ) hot wax to imp>t ! necess>y solidity4 ,9 *eap imitations ! glass balls are n l9$ at all1 b m]ely heat$ ) hydro*loric acid to give an iridesc5ce to ! surface2 sometimes !y are coat$ ) wax1 :i* c be scrap$ (f ) a knife4 ,,"p ,,ii--,,section ,a ,,preci\s ,,/ones ,,*apt] ,,xvi ,,diamond ,diamond has held pride ( place z *ief ( preci\s /ones ev] s9ce ! discov]y ( ! =m ( cutt+ kn[n z ! #8brilliant' reveal$ to full p]fection its amaz+ qualities2 & ju/ly s1 s9ce x comb9es 9 itself extreme h>dness1 high refraction1 l>ge col\r-disp]sion1 & brilliant lu/re4 ,a r\gh diamond1 especially f riv] gravels1 has (t5 a peculi> greasy appe>ance1 & is no m attractive to ! eye ?an a piece ( wa%+-soda4 ,x is !re=e easy to und]/& :y ! ,p]sians 9 ! ?irte5? c5tury plac$ ! pe>l1 ruby1 em]ald1 & ev5 p]idot be=e x1 & writ]s 9 ! ,middle ,ages frequ5tly e/eem$ x bel[ em]ald & ruby4 ,! ,indian lapid>ies1 :o 7 ! fir/ to realize t diamond c\ld be gr\nd ) its own p[d]1 discov]$ :at a wond]ful diff]5ce ! removal ( ! sk9 makes 9 ! appe>ance ( a /one4 ,!y1 h[ev]1 made no attempt to %ape a /one1 b m]ely poli%$ ! natural facets1 & only add$ num]\s small facets :5 !y wi%$ to conceal flaws or o!r imp]fections2 inde$1 ! fam\s travell]1 ,tav]ni]1 f :om mo/ ( our k ( e>ly m9+ 9 ,india is obta9$1 inv>iably f\nd t a /one cov]$ ) _m facets 0 badly flaw$4 ,! full radiant beauty ( a diamond comes to light only :5 x is cut 9 brilliant =m4 ,( all preci\s /ones diamond has ! simple/ composition2 x is m]ely cry/alliz$ c>bon1 ano!r =m ( :i* is ! humble & useful graphite1 commonly kn[n z #8black-lead4' ,surely nature has surpass$ all h] m>vell\s ef=ts 9 produc+ f ! same elem5t sub/ances ) su* div]g5t *>act]s z ! h>d1 brilliant1 & transp>5t diamond & ! s(t1 dull1 & opaque graphite4 ,x is1 h[ev]1 impossible to draw any %>p divid+ l9e betwe5 ! two2 s(t diamond passes ins5sibly into h>d graphite1 & vice v]sa4 ,bo>t1 or bort1 z x is sometimes writt51 is compos$ ( m9ute cry/als ( diamond arrang$ haphaz>dly2 x possesses no cleavage1 its h>dness is great] ?an t ( ! cry/als1 & its col\r is greyi% to blacki%4 ,c>bon1 c>bonado1 or black diamond1 :i* is compos$ ( /ill m m9ute cry/als1 is black & opaque1 & is p]ceptibly h>d] ?an ! cry/als4 ,x passes into graphite1 :i* v>ies 9 h>dness1 & may h any d5sity betwe5 #b,o & #c,o4 ,jewell]s apply ! t]m bo>t to cry/als or fragm5ts :i* are ( no s]vice z gems2 su* pieces are cru%$ to p[d] & us$ = cutt+ & poli%+ purposes4 ,diamonds1 :5 absolutely limpid & free f flaws1 are said to be ( ! #8fir/ wat]1' & are mo/ priz$ :5 devoid ( any t+e ( col\r except p]haps blui% 7,plate ,i1 ,fig4 #a74 ,/ones ) a slight t+e ( yell[ are t]m$ #8(f-col\r$1' & are f> less valuable4 ,^? ( a can>y-yell[ col\r 7,plate ,i1 ,fig4 #c71 h[ev]1 belong to a diff]5t category1 & h a decid$ attractiv5ess4 ,gre5i% /ones also are common1 ?\gh x is r>e to come across "o ) a really good %ade ( t col\r4 ,br[n /ones1 especially 9 ,s\? ,africa1 are n uncommon4 ,p9k /ones are less common1 & ruby-r$ & blue /ones are r>e4 ,^? ( ! la/-nam$ col\r h usually :at is kn[n z a #8/eely' %ade1 i4e4 !y are t+$ ) gre52 /ones ( a sapphire blue are v seldom met )1 & su* comm& high prices4 ,illu/ration3 ,,figs4 #eg--ei4--;,diamond ,cry/als4 ,diamond cry/allizes 7,figs4 #eg--ei & ,plate ,i1 ,fig4 #b7 9 octah$ra ) brilliant1 smoo? faces1 & occasionally 9 cubes ) r\gh pitt$ faces2 sometimes ?ree or six faces take ! place ( ea* octah$ron face1 & ! /one is almo/ sph]ical 9 %ape4 ,! surfaces ( ! cry/als are (t5 m>k$ ) equilat]al triangles1 :i* are suppos$ to repres5t ! effects ( incipi5t combu/ion4 ,tw9n$ cry/als1 9 :i* ! two individuals may be connect$ by a s+le plane or may be int]p5etrat+1 a /> %ape (t5 result+ 9 ! latt] case1 are common2 sometimes1 if ( ! octah$ron type1 !y are beautifully symmetrical4 ,! r\nd$ cry/als are frequ5tly cov]$ ) a peculi> gum-l sk9 :i* is some:at less h>d ?an ! cry/al itself4 ,a l>ge ,s\? ,african /one1 weigh+ #bg grams 7#acj c>ats7 & octah$ral 9 %ape1 :i* 0 ! gift ( ,john ,rusk91 & nam$ by him ! #8,col5so' aft] ! fir/ bi%op ( ,natal1 is exhibit$ 9 ! ,briti% ,museum 7,natural ,hi/ory72 its appe>ance is1 h[ev]1 m>r$ by its di/9ctly #8(f-col\r$' t9t4 ,! refraction ( diamond is s+le1 b local d\ble refraction is common1 indicat+ a /ate ( /ra9 :i* c (t5 be trac$ to an includ$ drop ( liquid c>bonic acid2 s great is ! /ra9 t _m a f9e /one has bur/ to fragm5ts on be+ remov$ f ! gr\nd 9 :i* x has la94 ,! refractive index = ! yell[ light ( a sodium flame is #bdage1 & ! slight v>iation f ?is mean value t has be5 obs]v$1 am\nt+ only to #jjjja1 te/ifies to ! purity ( ! composition4 ,! col\r-disp]sion is l>ge1 be+ z mu* z #jjdd1 9 :i* respect x surpasses all col\rless /ones1 b is exce$$ by sph5e & ! gre5 g>net f ! ,urals 7cf4 p4 #bag74 ,! lu/re ( diamond1 :5 poli%$1 is s *>act]i/ic z to be t]m$ adamant9e1 & is due to ! comb9ation ( high refraction & extreme h>dness4 ,diamond is transluc5t to ! ,x 7,rntg57 rays2 x phosphoresces "u ! action ( radium1 & ( a high-t5sion electric curr5t :5 plac$ 9 a vacuum tube1 & sometimes ev5 :5 expos$ to /rong sunlight4 ,"s diamonds fluoresce 9 sunlight1 turn+ milky1 & a few ev5 emit light :5 rubb$4 ,crookes f\nd t a diamond buri$ 9 radium bromide = a ye> _h acquir$ a lovely blue t9t1 :i* 0 n affect$ ev5 by heat+ to r$ness4 ,! specific gravity is likewise con/ant1 be+ #ceba1 ) a possible v>iation f t mean value ( #jjje2 b a great] range1 z might be expect$1 is f\nd 9 ! impure bo>t4 ,diamond is by f> ! h>de/ sub/ance 9 nature1 be+ m>k$ #aj 9 ,mohs's scale ( h>dness1 b x v>ies 9 itself2 /ones f ,borneo & ,new ,s\? ,wales are s p]ceptibly h>d] ?an ^? usually 9 ! lapid>ies' h&s1 t !y c be cut only ) _! own & n ord9>y diamond p[d]1 & "s difficulty 0 exp]i5c$ 9 cutt+ !m :5 !y fir/ came into ! m>ket4 ,x is int]e/+ to note t ! metal tantalum1 ! isolation ( :i* 9 comm]cial am\nt con/itut$ "o ( ! triumphs ( *emi/ry ( rec5t ye>s1 has ab\t ! same h>dness z diamond4 ,despite its extreme h>dness diamond readily cleaves "u a heavy bl[ 9 planes p>allel to ! faces ( ! regul> octah$ron1 a prop]ty utiliz$ = %ap+ ! /one previ\s to cutt+ x4 ,! fallaci\s1 b n unnatural1 idea 0 preval5t up to q mod]n times t a diamond w\ld1 ev5 if plac$ on an anvil1 resi/ a bl[ f a hamm]3 :o kn[s h[ _m f9e /ones h succumb$ to ?is illusory te/8 ,! fact t diamond c\ld be split 0 kn[n to ,indian lapid>ies at ! "t ( ,tav]ni]'s visit1 & x w\ld appe> f ,de ,boodt t 9 ! sixte5? c5tury ! cleavability ( diamond 0 n unkn[n 9 ,europe1 b x 0 n cr$it$ at ! "t & 0 soon =gott54 ,e>ly la/ c5tury ,wolla/on1 a fam\s *emi/ & m9]alogi/1 r$iscov]$ ! prop]ty1 &1 s x is said1 us$ 8 k to "s pr(it by pur*as+ l>ge /ones1 :i* because ( _! awkw>d %ape or ! pres5ce ( flaws 9 ! int]ior 7 reject$ by ! lapid>ies1 & sell+ !m back aga9 aft] cleav+ !m to suitable =ms4 ,x has already be5 rem>k$ 7p4 #gi7 t ! int]val 9 h>dness betwe5 diamond & corundum1 :i* comes next to x 9 ,mohs's scale1 is enorm\sly great] ?an t betwe5 corundum & ! s(te/ ( m9]als4 ,diamond c !re=e be cut only ) ! aid ( its own p[d]1 & ! cutt+ ( diamond is !re=e diff]5tiat$ f t ( o!r /ones1 ! preci\s-/one trade be+ to a l>ge ext5t divid$ into two di/9ct gr\ps1 namely1 deal]s 9 diamonds1 & deal]s 9 all o!r gem-/ones4 ,! "n ( ! species is d]iv$ f ! popul> =m1 adiam5tem1 ( ! ,lat9 adamantem1 itself ! allit]ative =m ( ! ,greek 1 mean+ ! unconqu]able1 9 allusion n m]ely to ! great h>dness b also to ! mi/ak5 idea already m5tion$4 ,bo>t probably comes f ! ,old-,fr5* bord or bort1 ba/>d4 ,at ! pres5t day diamonds are usually cut z brilliants1 ?\gh ! cont\r ( ! girdle may be circul>1 oval1 or drop-%ap$ to suit ! p>ticul> purpose = :i* ! /one is requir$1 or to keep ! weight z great z possible4 ,small /ones = bord]+ a l>ge col\r$ /one may also be cut z roses or po9ts4 ,a p]fect brilliant has #eh facets1 b small /ones may h n m ?an #dd1 & exceptionally l>ge /ones may ) advantage h _m m2 = in/ance1 on ! l>ge/ /one cut f ! ,cull9an diamond !re are no few] ?an #gd facets4 ,! description ( ! prop]ties ( diamond w\ld n be complete )\t a ref]5ce to ! o!r valuable1 if utilit>ian1 purposes to :i* x is put4 ,)\t its aid mu* ( mod]n eng9e]+ "w & m9+ op]ations w\ld be impossible except at ! co/ ( almo/ prohibitive exp5diture ( "t & money4 ,bor+ ?r\gh solid rock has be5 greatly facilitat$ by ! use ( ! diamond drill4 ,= ?is purpose c>bonado or black diamond is m s]viceable ?an s+le cry/als1 & ! price ( ! =m] has consequ5tly advanc$ f a nom9al figure up to #c to #ab a c>at4 ,! actual work+ "p ( ! drill consi/s ( a ca/-/eel r+4 ,! cr[n ( x has a numb] ( small depressions at regul> int]vals into :i* ! c>bonados are emb$d$4 ,on revolution ( ! drill an annul> r+ is cut1 leav+ a solid core :i* c be drawn to ! surface4 ,= cool+ ! drill & = wa%+ away ! detritus wat] is pump$ ?r\gh to ! work+ face4 ,! duration ( ! c>bonados dep5ds on ! nature ( ! rock & ! skill ( ! op]ator4 ,! mo/ tr\blesome rock is a s&/one or "o ) %>p diff]5ces 9 h>dness1 because ! c>bonados are liable to be torn out ( _! sett+4 ,an exp]i5c$ op]ator c tell by ! feel ( ! drill ! nature ( ! rock at ! work+ face1 & by v>y+ ! pressure c mitigate ! risk ( damage to ! drill4 ,! t5acity ( diamond r5d]s x mo/ suitable = wire-draw+4 ,! tung/5 filam5ts us$ 9 _m ( ! late/ =ms ( inc&esc5t electric lamps are prep>$ 9 ?is mann]4 ,diamond p[d] is us$ = cutt+ & turn+ ! h>d5$ /eel employ$ 9 mod]n armam5ts & = o!r m peaceful purposes4 ,al?\gh ne>ly all ! gem-/ones scrat* glass1 diamond alone c be satisfactorily employ$ to cut x along a def9ite edge4 ,any flake at r&om w n be suitable1 because x w te> ! glass & =m a jagg$ edge4 ,! be/ results are giv5 by ! junction ( two edges :i* d n meet 9 too obtuse an angle2 two edges ( ! rhombic dodecah$ron meet ! requirem5ts admirably4 ,! /ones us$ by ! glazi]s are m9ute 9 size1 be+ n mu* l>g] ?an a p9's head1 & ?irty ( !m on an av]age g to ! c>at4 ,!y are set 9 copp] or brass4 ,"s little skill is ne$$ to obta9 ! be/ results4 ,! value ( a diamond has always be5 det]m9$ l>gely by ! size ( ! /one1 ! old rule be+ t ! rate p] c>at %\ld be multipli$ by ! squ>e ( ! weight 9 c>ats2 ?us1 if ! rate be #aj1 ! co/ ( a two-c>at /one is f\r times ?is sum1 or #dj1 ( a ?ree-c>at /one #ij1 & s on4 ,= a c5tury1 f #agej to #ahej1 ! rate rema9$ almo/ con/ant at #d = r\gh1 #f = rose-cut1 & #h = brilliant-cut diamonds4 ,s9ce ! latt] date1 ow+ to ! increase 9 ! supply ( gold1 ! gr[? ( ! sp5d+ p[] ( ! _w1 & ! gradual fall+ (f 9 ! productiv5ess ( ! ,brazilian fields1 ! rate /eadily increas$ ab\t #aj p] c5t4 ea* ye>1 until 9 #ahfe ! rate = brilliants 0 #ah4 ,! rise 0 *eck$ by ! discov]y ( ! ,s\? ,african m9es2 moreov]4 s9ce comp>atively l>ge /ones are pl5tiful 9 ^! m9es1 ! rule ( ! increase 9 ! price ( a /one by ! squ>e ( its weight no long] holds4 ,! rate = ! mo/ p]fect /ones /ill rema9s high1 because su* are n s common 9 ! ,s\? ,african m9es4 ,! classification#g adopt$ by ! syndicate ( ,london diamond m]*ants :o place ^u ! m>ket ! output ( ! ,de ,be]s gr\p ( m9es is z foll[s3--7a7 ,blue-:ite1 7b7 :ite1 7c7 silv]y ,cape1 7d7 f9e ,cape1 7e7 ,cape1 7f7 f9e bywat]1 7g7 bywat]1 7h7 f9e light br[n1 7i7 light br[n1 7j7 br[n1 7k7 d>k br[n4 ,bywat]s or byes are /ones t+$ ) yell[4 ,! rate p] c>at = cut /ones 9 ! blue-:ite & ! bywat] gr\ps is3-- ,,blue-,,:ite4 ,,bywat]4 #e-;c>at /one #dj-fj #bj-be #a #cj-dj #aj-ae #bj-be #h-ab #ae-ah #f-aj ,mle #ab-ae #e-h ,mle are /ones small] ?an a qu>t] ( a c>at4 ,x w be notic$ t ! prices dep>t l>gely f ! old rule2 ?us tak+ ! rate = a c>at blue-:ite /one1 ! price ( a five-c>at /one %\ld be f #aej-bjj a c>at1 & = a qu>t]-c>at /one only #g1 #ajs4 to #aj a c>at4 ,!re happ5s to be at ! "t ( writ+ v little dem& = five-c>at /ones4 ,( c\rse1 ! prices giv5 are subject to con/ant fluctuation dep5d+ ^u ! supply & dem&1 & ! :ims ( fa%ion4 ,,*apt] ,,xvii ,,occurr5ce ,,( ,,diamond ,! :ole ( ! diamonds kn[n 9 anci5t times 7 obta9$ f ! s-call$ ,golconda m9es 9 ,india4 ,golconda itself1 n[ a des]t$ =tress ne> ,hyd]abad1 0 m]ely ! m>t :]e ! diamonds 7 b\ght & sold4 ,! diamond-be>+ di/rict actually spread ov] a wide area on ! ea/]n side ( ! ,deccan1 ext5d+ f ! ,p9n] ,riv] 9 ! ,madras ,presid5cy nor?w>ds to ! ,riv]s ,son & ,khan1 tribut>ies ( ! ,ganges1 9 ,bundelkh&4 ,! ri*e/ m9es1 :]e ! l>ge hi/orical /ones 7 f\nd1 are 9 ! s\?1 mo/ly ne> ! ,ki/na ,riv]4 ,! diamonds 7 discov]$ 9 s&/one1 or conglom]ate1 or ! s&s & gravels ( riv]-b$s4 ,! m9es 7 visit$ 9 ! middle ( ! sev5te5? c5tury by ! ,fr5* travell] & jewell]1 ,tav]ni]1 :5 travell+ on a commission = ,l\is ,,xiv1 & he aft]w>ds publi%$ a c>eful description ( !m & ( ! me?od ( work+ !m4 ,! m9es seem to h be5 exhau/$ 9 ! sev5te5? c5tury2 at any rate1 ! prospect+1 :i* has be5 spasmodically c>ri$ on dur+ ! la/ two c5turies1 has prov$ almo/ abortive4 ,) ! exception ( ! ,koh-i-nor1 all ! l>ge ,indian diamonds 7 probably discov]$ n long be=e ,tav]ni]'s visit4 ,! diamonds kn[n to ,pl9y1 & 9 8 "t1 7 q small1 & x is d\btful if any /ones ( consid]able size came to light be=e ,a4,d4 #ajjj4 ,india enjoy$ ! monopoly ( supply+ ! _w's dem& = diamonds up to ! discov]y1 9 #agbe1 ( ! preci\s /one 9 ,brazil4 ,small /ones 7 detect$ by ! m9]s 9 ! gold wa%+s at ,tejuco1 ab\t eighty miles 7#abi km47 f ,rio de ,janeiro1 9 ! ,s]ro d ,frio di/rict ( ! ,/ate ( ,m9as ,g]aes4 ,! discov]y naturally caus$ great excitem5t4 ,s _m diamonds 7 f\nd t 9 #agbg some?+ l a slump took place 9 _! value4 ,9 ord] to keep up prices1 ! ,dut* m]*ants1 :o ma9ly controll$ ! ,indian output1 ass]t$ t ! diamonds _h n be5 f\nd 9 ,brazil at all1 b 7 inf]ior ,indian /ones %ipp$ to ,brazil f ,goa4 ,! tables 7 neatly turn$ :5 diamonds 7 actually %ipp$ f ,brazil to ,goa1 & export$ !nce to ,europe z ,indian /ones4 ,?is c\rse & ! cont9u\s developm5t ( ! diamond di/rict 9 ,brazil r5d]$ x impossible to hoodw9k ! _w indef9itely4 ,! drop 9 prices 01 h[ev]1 /ay$ by ! action ( ! ,portuguese gov]nm5t1 :o exact$ su* heavy duties & impos$ su* on]\s conditions t f9ally no "o w\ld und]take to "w ! m9es4 ,accord+ly1 9 #aggb diamond-m9+ 0 decl>$ a royal monopoly 9 ,brazil1 & su* x rema9$ until ! sev]ance ( ,brazil f ,portugal 9 #ahcd1 :5 private m9+ 0 p]mitt$ by ! new gov]nm5t subject to ! paym5t ( reasonable royalties4 ,! indu/ry 0 enorm\sly /imulat$ by ! discov]y1 9 #ahdd1 ( ! rem>kably ri* fields 9 ! ,/ate ( ,bahia1 especially at ,s]ra da ,c9cor1 :]e c>bonado1 or black diamond1 fir/ came to light1 b aft] a few ye>s1 ow+ to ! difficulties ( supply+ lab\r1 ! unheal?9ess ( ! climate1 & ! high co/ ( liv+1 ! yield fell (f & gradually decl9$1 until ! importance ( ! fields 0 f9ally eclips$ by ! rise ( ! ,s\? ,african m9es4 ,! ,brazilian m9es h prov$ v productive1 b *iefly 9 small diamonds1 /ones above a c>at 9 weight be+ few 9 comp>ison4 ,! l>ge/ /one1 to :i* ! "n1 ! ,/> ( ! ,s\?1 0 appli$1 weigh$ 9 ! r\gh #bed c>ats2 x 0 discov]$ at ! ,bagagem m9es 9 #ahec4 ,! quality ( ! diamonds is good1 _m ( !m hav+ ! highly-priz$ blui%-:ite col\r4 ,! pr9cipal diamond-be>+ di/ricts ( ,brazil c5tre at ,diamant9a1 z ,tejuco 0 re-nam$ aft] ! discov]y ( diamonds1 ,gro ,magor1 & ,bagagem 9 ! ,/ate ( ,m9as ,g]aes1 at ,diamant9a 9 ! ,/ate ( ,bahia1 & at ,goyz & ,matto ,grosso 9 ! ,/ates ( ! same names4 ,! diamonds occur *iefly 9 cascalho1 a gravel1 conta9+ l>ge masses ( qu>tz & small p>ticles ( gold1 :i* is suppos$ to be d]iv$ f a qu>tzose v>iety ( micace\s slate kn[n z itacolumite4 ,! m9es are n[ to "s ext5t be+ work$ by sy/ematic dr$g+ ( ! riv]-b$s4 ,e>ly 9 #ahfg ! *ildr5 ( a ,bo] f>m]1 ,daniel ,jacobs1 :o dwelt ne> ,hopet[n on ! banks ( ! ,orange ,riv]1 pick$ up 9 ! c\rse ( play ne> ! riv] a :ite pebble1 :i* 0 de/9$ n only to m>k ! comm5cem5t ( a new epo* 9 ! record ( diamond m9es1 b to *ange ! :ole c\rse ( ! hi/ory ( ,s\? ,africa4 ,?is pebble attract$ ! att5tion ( a neighb\r1 ,s*alk van ,niek]k1 :o suspect$ t x might be ( "s value1 & (f]$ to buy x4 ,mrs4 ,jacobs1 h[ev]1 gave x him1 laugh+ly sc\t+ ! idea ( accept+ money = a m]e pebble4 ,van ,niek]k %[$ x to a travell+ trad]1 by "n ,john ,o',reilly1 :o und]took to obta9 :at he c\ld = x on condition t !y %>$ ! proce$s4 ,e "o he met laugh$ to scorn ! idea t ! /one _h any value1 & x 0 once ?r[n away & only recov]$ aft] "s se>* 9 a y>d1 b at l5g? he %[$ x to ,lor5zo ,boyes1 ! ,act+ ,civil ,commission] at ,colesb]g1 :o1 f its extreme h>dness1 ?\ght x might be diamond & s5t x to ! m9]alogi/1 ,w4 ,guybon ,a!r/on1 ( ,graham/[n1 = det]m9ation4 ,s unc]ta9 0 ,boyes ( its value t he did n ev5 seal up ! envelope conta9+ x1 mu* less regi/] ! package4 ,a!r/on f\nd imm$iately t ! long-scorn$ pebble 0 really a f9e diamond1 weigh+ #ba-c_/af c>ats1 & ) ,o',reilly's cons5t he submitt$ x to ,sir ,philip ,wodeh\se1 ,gov]nor at ! ,cape4 ,! latt] pur*as$ x at once = #ejj1 & dispat*$ x to be %[n at ! ,p>is ,exhibition ( t ye>4 ,x did n1 h[ev]1 attract mu* att5tion2 *im]ical tales ( diamond f9ds 9 remote p>ts ( ! _w are n unkn[n4 ,inde$1 = "s "t only a few small /ones 7 pick$ up beside ! ,orange ,riv]1 & no "o believ$ 9 ! exi/5ce ( any ext5sive diamond deposit4 ,h[ev]1 all d\bt z to ! advisibility ( prospect+ ! di/rict 0 settl$ by ! discov]y ( ! sup]b diamond1 aft]w>ds kn[n z ! #8,/> ( ,s\? ,africa1' :i* 0 pick$ up 9 ,m>* #ahfi by a %eph]d boy on ! ,z5dfonte9 f>m ne> ! ,orange ,riv]4 ,van ,niek]k1 on ! al]t = news ( fur!r discov]ies1 at once hurri$ to ! spot & pur*as$ ! /one f ! boy = five hundr$ %eep1 t5 ox51 & a horse1 :i* seem$ to ! boy untold weal?1 b 0 n a ti! ( ! #aa1bjj :i* ,lili5feld ,bros41 ( ,hopet[n1 gave ,van ,niek]k4 ,illu/ration3 ,,plate ,,xv ,,kimb]ley ,,m9e1 #ahga ,illu/ration3 ,,plate ,,xvi ,,kimb]ley ,,m9e1 #ahgb ,?is rem>kable discov]y attract$ imm$iate att5tion to ! pot5tialities ( a c\ntry :i* produc$ diamonds ( su* a size1 & prospectors began to sw>m into ! di/rict1 gradually spread+ up ! ,vaal ,riv]4 ,= "s little "t n mu* success 0 exp]i5c$1 b at l5g?1 e>ly 9 #ahgj1 a ri* f9d 0 made at ,klipdrift1 n[ kn[n z ,b>kly ,we/1 :i* 0 on ! banks ( ! ,vaal ,riv] imm$iately opposite ! ,mission camp at ,pniel4 ,! numb] ( m9]s /eadily increas$ until ! population on ! two sides ( ! riv] includ$ altoge!r "s f\r or five ?\s& p1 & !re 0 e appe>ance ( /ability 9 ! exi/+ ord] ( ?+s4 ,b a va/ *ange came ov] ! sc5e ^u ! discov]y ( /ill ri*] m9es ly+ to ! s\?-ea/ & "s di/ance f ! riv]4 ,! gr\nd 0 actually situat$ on ! r\te trav]s$ by p>ties hurry+ to ! ,vaal ,riv]1 b no "o dream$ ( ! weal? t lay "u _! feet4 ,! fir/ discov]y 0 made 9 ,augu/ #ahgj at ! f>m ,jag]sfonte91 ne> ,fauresmi? 9 ,orange ,riv] ,colony1 by ,de ,kl]k1 ! intellig5t ov]se]1 :o notic$ 9 ! dry b$ ( a /ream a numb] ( g>nets1 &1 kn[+ t !y (t5 accompani$ diamond1 _h ! curiosity to inve/igate ! po9t4 ,he 0 imm$iately rew>d$ by f9d+ a f9e diamond weigh+ #ej c>ats4 ,9 ! foll[+ mon? diamonds 7 discov]$ ab\t tw5ty miles f ,klipdrift at ,dutoitspan on ! ,dor/fonte9 f>m1 & a little lat] also on ! contigu\s f>m ( ,bultfonte92 a diamond 0 actually f\nd 9 ! mort> us$ 9 ! home/ead ( ! latt] f>m4 ,e>ly 9 ,may #ahga diamonds 7 f\nd ab\t two miles away on ,de ,be]s' f>m1 ,vooruitzigt1 & two mon?s lat]1 9 ,july1 a f> ri*] f9d 0 made on ! same f>m at a spot :i* 0 fir/ nam$ ,colesb]g ,kopje1 ! initial b& ( prospectors hav+ come f ! t[n ( t "n ne> ! ,orange ,riv]1 b 0 subsequ5tly kn[n z ,kimb]ley aft] ! ,secret>y ( ,/ate = ! ,colonies at t "t4 ,soon a l>ge & prosp]\s t[n sprang up close to ! m9es2 x rapidly grew 9 size & importance1 & to ?is day rema9s ! c5tre ( ! diamond-m9+ indu/ry4 ,subsequ5t prospect+ prov$ almo/ blank until ! discov]y ( ! ,premi] or ,wesselton m9e on ,wesselton f>m1 ab\t f\r miles f ,kimb]ley1 9 ,septemb] #ahij2 x receiv$ ! =m] "n aft] ,rhodes1 :o 0 ,premi] ( ,cape ,colony at t date4 ,no fur!r discov]y ( any importance 0 made until1 9 #aijb1 diamonds 7 f\nd ab\t tw5ty miles nor?-we/-nor? ( ,pretoria 9 ! ,transvaal1 at ! new ,premi] m9e1 n[ fam$ z ! produc] ( ! gigantic ,cull9an diamond4 ,illu/ration3 ,,plate ,,xvii ,,kimb]ley ,,m9e1 #ahgd ,illu/ration3 ,,plate ,,xviii ,,kimb]ley ,,m9e1 #ahha ,! ,kimb]ley m9es 7 at fir/ kn[n z ! #8dry digg+s' on acc\nt ( _! arid surr\nd+s 9 contradi/9ction to ! #8riv] digg+s' by ! ,vaal4 ,! de>? ( wat] 0 at fir/ "o ( ! great difficulties 9 ! way ( work+ ! =m] m9es1 al?\gh subsequ5tly ! accumulation ( und]gr\nd wat] at l[] levels prov$ a great ob/acle to ! work+ ( ! m9es4 ,! #8riv] digg+s' 7 ( a type simil> to t met ) 9 ,india & ,brazil1 ! diamonds occurr+ 9 a gravelly deposit ( limit$ ?ickness b5ea? :i* 0 b>r5 rock1 b ! ,kimb]ley m9es pres5t$ a ph5om5on hi!rto )\t prec$5t 9 ! :ole hi/ory ( diamond m9+4 ,! diamonds 7 f\nd 9 a loose surface deposit1 :i* 0 easily work$1 & = "s "t ! prospectors ?\ght t ! und]ly+ lime/one correspond$ to ! b$rock ( ! riv] gravel1 until at l5g? "o m curi\s ?an 8 fell[s inve/igat$ ! yell[i% gr\nd und]nea?1 & f\nd to 8 surprise t x 0 ev5 ri*] ?an ! surface lay]4 ,imm$iately a ru% 0 made back to ! des]t$ claims1 & ! m9es 7 busi] ?an ev]4 ,?is #8yell[ gr\nd1' z x is popul>ly call$1 0 mu* decompos$ & easy1 !re=e1 to "w & sift4 ,ab\t fifty to sixty feet 7#ae-ah m47 bel[ ! surface1 h[ev]1 x pass$ into a f> h>d] rock1 :i* f its col\r is kn[n z ! #8blue gr\nd'2 ?is also1 to ! unexpect$ pleasure ( ! m9]s1 turn$ out to conta9 diamonds4 ,difficulties arose z ea* claim1 #cj by #cj ,dut* feet 7ab\t #ca ,engli% feet or #ide metres squ>e7 9 area1 0 work$ d[nw>ds4 ,9 ! ,kimb]ley m9e 7,plate ,,xvi7 access to ! v>i\s claims 0 secur$ by reta9+ p>allel /rips1 #ae feet wide1 ea* claim be+1 !re=e1 r$uc$ 9 wid? to #bb feet1 to =m roadways runn+ f side to side ( ! m9e 9 "o direction4 ,^!1 h[ev]1 soon gave way1 n only because ( ! fall+ ( ! e>? compos+ !m1 b because !y 7 und]m9$ & und]cut by ! own]s ( ! adjac5t claims4 ,by ! end ( #ahgb ! la/ roadway _h disappe>$1 & ! m9e pres5t$ ! appe>ance ( a va/ pit4 ,9 ord] to obta9 access to ! claims )\t intrud+ on ^? ly+ betwe51 & to provide = ! haul+ ( ! loads ( e>? to ! surface1 an +5i\s sy/em ( wire cables 9 ?ree ti]s 7,plate ,,xvii7 0 erect$1 ! l[e/ ti] be+ connect$ to ! out]mo/ claims1 ! second to claims f>!r f ! edge1 & ! highe/ to claims 9 ! c5tre ( ! pit4 ,! m9e at t date pres5t$ a mo/ rem>kable spectacle1 resembl+ an enorm\s radiat+ cobweb1 :i* _h a weird *>m by night z ! moonlight s(tly illum9at$ x1 & by day1 ow+ to ! p]petual r+ ( ! flang$ :eels ( ! trucks on ! runn+ wires1 twang$ l "s gigantic olian h>p4 ,?is sy/em fulfill$ its purpose admirably until1 ) increas+ dep? ( ! work+s1 o!r s]i\s difficulties arose4 ,depriv$ ( ! support ( ! h>d blue gr\nd1 ! walls ( ! m9e t5d$ to collapse1 & additional tr\ble 0 caus$ by ! und]gr\nd wat] t p]colat$ into ! m9e4 ,by ! end ( #ahhc ! floor ( ! ,kimb]ley m9e 0 almo/ entirely cov]$ by falls ( #8reef' 7,plate ,,xviii71 z ! surr\nd+ rocks are t]m$1 ! dep? !n be+ ab\t #djj feet 7#abb m474 ,9 ! ,de ,be]s m9e1 9 spite ( ! precaution tak5 to prev5t falls ( reef by cutt+ ! walls ( ! m9e back 9 t]races1 falls occurr$ cont9u\sly 9 #ahhd1 & by #ahhg1 at a dep? ( #cej feet 7#ajg m471 all attempts at op5 work+ _h to be ab&on$4 ,9 ! ,dutoitspan m9e buttresses ( blue gr\nd 7 left1 :i* held back ! reef = "s ye>s1 b ultimately ! m9e became unsafe1 & 9 ,m>* #ahhf a disa/r\s fall took place1 9 :i* eighte5 m9]s--eight :ite m5 & t5 ,kafirs--lo/ _! lives4 ,! ,bultfonte9 m9e 0 work$ to ! great dep? ( #ejj feet 7#aeb m471 b falls occurr$ 9 #ahhi & put an end to op5 work+4 ,9 all cases1 !re=e1 ! ultimate end 0 ! same3 ! floor ( ! m9e became cov]$ ) a mass ( wor?less reef1 :i* r5d]$ m9+ f above gr\nd dang]\s1 &1 inde$1 impossible except at prohibitive co/4 ,x 0 !n cle>ly necess>y to effect access to ! diamond-be>+ gr\nd by means ( %afts sunk at a suffici5t di/ance f ! m9e to remove any fe> ( falls ( reef4 ,= su* s*emes co-op]ative work+ 0 absolutely ess5tial4 ,plate ,,xix illu/rates ! desolate "* ( ! ,kimb]ley m9e above gr\nd & ! va/ness ( ! yawn+ pit1 :i* is ov] #ajjj feet 7#cjj m47 9 dep?4 ,illu/ration3 ,,plate ,,xix ,,kimb]ley ,,m9e ,,at ,,! ,,pres5t ,,day ,illu/ration3 ,,plate ,,xx ,,wesselton 7op57 ,,m9e ,a c]ta9 am\nt ( l9k+ up ( claims _h already tak5 place1 b1 al?\gh _m m5 mu/ h se5 t ! complete amalgamation ( ! int]e/s 9 ea* m9e 0 imp]ative1 two m5 alone _h ! capacity to br+ _! ideas to fruition4 ,c4 ,j4 ,rhodes 0 ! pr9cipal ag5t 9 ! =mation 9 ,april #ahhj ( ! ,de ,be]s ,m9+ ,company1 :i* rapidly absorb$ ! rema9+ claims 9 ! m9e1 & 0 re-=m$ 9 #ahhg z ! ,de ,be]s ,consolidat$ ,m9+ ,company4 ,meantime1 ,b>nett ,isaacs1 bett] kn[n by ! cognom5 ,b>nato1 :i* _h be5 adopt$ by 8 bro!r ,h5ry :5 engag$ 9 e>n+ 8 livelihood 9 ! diamond fields z an ent]ta9]1 _h secur$ ! major int]e/s 9 ! ,kimb]ley m9e4 ,rhodes saw t1 = effective work+ ( ! two m9es by any sy/em ( und]gr\nd work+1 !y mu/ be "u "o managem5t1 b to all sugge/ions ( amalgamation ,b>nato rema9$ deaf1 & at la/ ,rhodes det]m9$ to secure control ( ! ,kimb]ley m9e at all co/s4 ,! /ory ( ! titanic /ruggle betwe5 ^! two m5 =ms "o ( ! epics ( f9ance4 ,ev5tually1 :5 %>es 9 ! ,kimb]ley m9e _h be5 boom$ to an extraord9>y height1 & ! price ( diamonds _h fall5 z l[ z #ahs4 a c>at1 ,b>nato gave way1 & 9 ,july #ahhi ! ,kimb]ley m9e 0 absorb$ by ! ,de ,be]s ,company on paym5t ( ! enorm\s sum ( #e1cch1fej4 ,%ortly aft]w>ds !y und]took ! work+ ( ! ,dutoitspan & ! ,bultfonte9 m9es1 & 9 ,janu>y #ahif !y acquir$ ! ,premi] or ,wesselton m9e4 ,! int]e/s 9 ! ,jag]sfonte9 m9e 7 9 #ahhh unit$ 9 ! ,new ,jag]sfonte9 ,m9+ & ,exploration ,company1 & ! m9e is n[ work$ also by ! ,de ,be]s ,company4 ,?us1 until ! developm5t ( ! new ,premi] m9e 9 ! ,transvaal1 ! ,de ,be]s ,company practically controll$ ! diamond m>ket4 ,! developm5t ( ?is la/ m9e 0 begun s rec5tly1 & its size is s va/--! longe/ diamet] be+ half a mile--t op5-cut work+ is likely to cont9ue = "s ye>s4 ,illu/ration3 ,,plate ,,xxi ,,load+ ,,! ,,blue ,,gr\nd ,,on ,,! ,,floors1 ,,& ,,pl\gh+ ,,x ,,ov] ,illu/ration3 ,,plate ,,xxii ,,wa%+-,,ma*9es ,,= ,,conc5trat+ ,,! ,,blue ,,gr\nd ,?\gh v>y+ slightly 9 details1 ! me?ods ( work+ ! m9es are id5tical 9 pr9ciple4 ,f ! /eeply incl9$ %aft horizontal gall]ies are run diagonally "r across ! m9e1 ! v]tical int]val betwe5 successive gall]ies be+ #dj feet4 ,f ea* gall]y side gall]ies are run at "r angles to x & p>allel to ! work+ face4 ,! blue gr\nd is work$ sy/ematically backw>ds f ! work+ face4 ,! mass is /op$1 i4e4 drill$ & brok5 f ! bottom upw>ds1 until only a ?9 ro( is left4 ,z soon z ! section is work$ out & ! mat]ial remov$1 ! ro( is all[$ to fall 91 & "w is begun on ! next section ( ! same level2 at ! same "t ! fir/ section on ! level next bel[ is op5$ out4 ,?us "w is simultane\sly c>ri$ on 9 sev]al levels1 & a v]tical plane w\ld int]sect ! work+ faces 9 a /raight l9e obliquely incl9$ to ! v]tical direction 7,fig4 #fj74 ,:5 fre%ly m9$1 ! blue gr\nd is h>d & compact1 b x soon dis9tegrates "u atmosph]ic influ5ce4 ,inde$1 ! yell[ gr\nd itself 0 m]ely decompos$ blue gr\nd4 ,no imm$iate attempt is made1 !re=e1 to retrieve ! preci\s /ones4 ,! blue gr\nd is spread on to ! #8floors' 7,plate ,,xxi71 i4e4 spaces ( op5 veldt :i* h be5 cle>$ ( bu%es & inequalities1 to ! dep? ( a c\ple ( feet1 & rema9s !re = p]iods rang+ f six mon?s to two ye>s1 dep5d+ on ! quality ( ! blue gr\nd & ! am\nt ( ra9fall4 ,to ha/5 ! dis9tegration ! blue gr\nd is frequ5tly pl\gh$ ov] & occasionally wat]$1 a rem>kable introduction ( agricultural me?ods into m9+ op]ations4 ,no elaborate patroll+ or gu>d+ is requir$1 because ! diamonds are s sp>sely1 ?\gh regul>ly1 scatt]$ ?r\gh ! mass t ev5 ( ! actual work]s 9 ! m9es b few h ev] se5 a /one 9 ! blue gr\nd4 ,:5 suffici5tly brok5 up1 x is c>t$ to ! wa%+ & conc5trat+ ma*9es1 by means ( :i* ! diamonds & ! heavi] con/itu5ts are sep>at$ f ! light] mat]ial4 ,illu/ration3 ,,fig4 #fj4--,v]tical ,section ( ,diamond ,pipe1 %[+ ,tunnels & ,/opes4 ,=m]ly ! diamonds 7 pick$ out f ! conc5trates by means ( ! ke5 eyes ( skill$ natives2 b ! process has be5 va/ly simplifi$ & ! risk ( !ft entirely elim9at$ by ! rem>kable discov]y made 9 #ahig by ,f4 ,kir/51 ( ! ,de ,be]s ,company1 t ( all ! heavy con/itu5ts ( ! blue gr\nd diamond alone1 ) ! exception ( an occasional corundum & zircon1 :i* are easily sort$ out aft]w>ds1 adh]es to grease m readily ?an to wat]4 ,9 ?is +5i\s ma*9e1 ! #8jigg]' or #8greas]' 7,plate ,,xxiii7 z x is commonly t]m$1 ! conc5trates are wa%$ ov] a s]ies ( galvaniz$-iron trays1 :i* are cov]$ ) a ?ick coat ( grease4 ,! trays are slightly incl9$ d[nw>ds1 & are kept by ma*9]y 9 con/ant sideways motion backw>ds & =w>ds4 ,s accurate is ! work+ ( ?is device t few diamonds succe$ 9 gett+ beyond ! fir/ tray1 & none progress z f> z ! ?ird1 :i* is add$ z an additional precaution4 ,! :ole app>atus is securely cov]$ 9 s t !re is no risk ( !ft dur+ ! op]ation4 ,! trays are p]iodically remov$1 & ! grease is scrap$ (f & boil$ to release ! diamonds1 ! grease itself be+ us$ ov] aga9 on ! trays4 ,?is is ! fir/ "t 9 ! :ole c\rse ( extraction f ! m9es t ! diamonds are actually h&l$4 ,! /ones are n[ pass$ on to ! sort]s1 :o sep>ate !m into p>cels accord+ to _! size1 %ape1 & quality4 ,illu/ration3 ,,plate ,,xxiii ,,diamond-,,sort+ ,,ma*9es ,illu/ration3 ,,plate ,,xxiv ,,kafirs ,,pick+ ,,out ,,diamonds ,! classification at ! m9es is fir/ into gr\ps by ! %ape3 7#a7 close goods1 7#b7 spott$ /ones1 7#c7 rejection cleavage1 7#d7 f9e cleavage1 7#e7 light br[n cleavage1 7#f7 ord9>y & rejection cleavage1 7#g7 flats1 7#h7 macles1 7#i7 rubbi%1 7#aj7 bo>t4 ,close goods are :ole cry/als :i* conta9 no flaws & c be cut into s+le /ones4 ,spott$ /ones1 z _! "n sugge/s1 conta9 spots :i* necessitate removal1 & cleavage includes /ones :i* are s full ( flaws t !y h to be cleav$ or split into two or m /ones4 ,flats are di/ort$ octah$ra1 & macles are tw9n$ octah$ra4 ,rubbi% is mat]ial :i* c be utiliz$ only = gr9d+ purposes1 & bo>t consi/s ( r\nd d>k /ones :i* are invaluable = rock-drills4 ,^! gr\ps are aft]w>ds grad$ into ! foll[+ subdivisions1 dep5d+ on increas+ dep? ( yell[i% t9t3 7a7 blue-:ite1 7b7 fir/ ,cape1 7c7 second ,cape1 7d7 fir/ bye1 7e7 second bye1 7f7 (f-col\r1 7g7 light yell[1 7h7 yell[4 ,x is1 h[ev]1 only ! fir/ gr\p t is s m9utely subdivid$4 ,aft] be+ pur*as$1 ! p>cels are split up aga9 some:at diff]5tly = ! ,london m>ket 7cf4 p4 #acf71 & ! deal]s re-arrange ! /ones accord+ to ! purpose = :i* !y are requir$4 ,=m]ly a syndicate ( ,london m]*ants took ! :ole ( ! produce ( ! ,kimb]ley m9es at a previ\sly arrang$ price p] c>at1 b at ! pres5t "t ! diamonds are sold by c]ta9 ,london firms on commission4 ,! products ( ea* m9e %[ diff]5ces 9 ei!r =m or col\r :i* enable an exp]t readily to recognize _! orig94 ,! old digg+s by ! ,vaal ,riv] yield$ f9] & m col\rless /ones ?an ^? f\nd 9 ! dry digg+s & ! m9es und]ly+ !m4 ,! ,s\? ,african diamonds1 tak5 z a :ole1 are always slightly yell[i% or #8(f-col\r$'2 ! m9es are1 inde$1 rem>kable = ! numb] ( f9e & l>ge1 can>y-yell[ & br[n1 /ones produc$4 ,! ,kimb]ley m9e yields a fair p]c5tage ( :ite1 & a l>ge numb] ( tw9n$ & yell[ /ones4 ,! yield ( ! ,de ,be]s m9e comprises mo/ly t9t$ /ones--yell[ & br[n1 occasionally silv] capes1 & v seldom /ones free f col\r4 ,! ,dutoitspan m9e is not$ = its h>ve/ ( l>ge yell[ diamonds2 x also produces f9e :ite cleavage & small :ite octah$ra4 ,! /ones f\nd 9 ! ,bultfonte9 m9e are small & spott$1 b1 on ! o!r h&1 ! yield has be5 unusually regul>4 ,! ,premi] or ,wesselton m9e yields a l>ge proportion ( flawless octah$ra1 b1 above all1 a l>ge numb] ( beautiful deep-orange diamonds4 ,( all ! ,s\? ,african m9es ! ,jag]sfonte9 9 ! ,orange ,riv] ,colony alone supplies /ones ( ! highly-priz$ blue-:ite col\r & /eely lu/re *>act]i/ic ( ! old ,indian /ones4 ,! new ,premi] m9e 9 ! ,transvaal is prolific1 b mo/ly 9 (f-col\r$ & l[-grade /ones1 ! ,cull9an diamond be+ a rem>kable exception4 ,to illu/rate ! amaz+ productiv5ess ( ! ,s\? ,african m9es1 x may be m5tion$ t1 accord+ to ,g>dn] ,f4 ,williams1 ! ,kimb]ley gr\p ( m9es 9 sixte5 ye>s yield$ #cf million c>ats ( diamonds1 & ! annual output ( ! ,jag]sfonte9 m9e av]ages ab\t a qu>t] ( a million c>ats1 :]eas ! total output ( ! ,brazil m9es1 = ! :ole ( ! long p]iod dur+ :i* !y h be5 work$1 b>ely exce$s #ac million c>ats4 ,! av]age yield ( ! ,s\? ,african m9es1 h[ev]1 p]ceptibly dim9i%es z ! dep? ( ! m9es increases4 ,! mo/ int]e/+ po9t connect$ ) ! ,s\? ,african diamond m9es1 view$ f ! sci5tific /&po9t1 is ! light t !y h ?r[n on ! "q ( ! orig9 ( ! diamond1 :i* previ\sly 0 an incompreh5sible & app>5tly insoluble problem4 ,9 ! old] m9es1 j z at ! riv] digg+s by ! ,vaal1 ! /ones are f\nd 9 a gravelly deposit t has result$ f ! dis9tegration ( ! rocks ?r\gh :i* ! adjac5t riv] has pass$1 & x is cle> t ! diamond _c h be5 =m$ 9 situ "h2 x _h be5 suspect$1 & n[ !re is no d\bt1 t ! itacolumite rock ( ,brazil has consolidat$ r\nd ! diamonds :i* are scatt]$ ?r\gh x1 & t x _c be ! p>5t rock4 ,! occurr5ce at ,kimb]ley is v diff]5t4 ,^! m9es are funnels :i* g d[nw>ds to unkn[n dep?s2 !y are m or less oval 9 section1 becom+ n>r[] ) increas+ dep?1 & are evid5tly ! result ( "s eruptive ag5cy4 ,! ,kimb]ley m9e has be5 work$ to a dep? ( ne>ly #djjj feet 7#abjj m471 & no signs ( a t]m9ation h z yet appe>$4 ,! blue gr\nd :i* fills ^! #8pipes1' z !y are t]m$1 mu/ h be5 =c$ up f bel[1 s9ce x is %>ply diff]5tiat$ f ! surr\nd+ c\ntry rocks4 ,?is blue gr\nd is a brecciat$ p]idotite ( peculi> con/itution1 to :i* ! well-kn[n petrologi/1 ,c>vil ,lewis1 :o made a c>eful /udy ( x1 gave ! "n kimb]lite4 ,! blue col\r te/ifies to its ri*ness 9 iron1 & x is to ! oxidation ( ! iron con/itu5t1 t ! *ange ( col\r to yell[ 9 ! upp] levels is due4 ,ow+ to ! %afts t h be5 sunk = work+ ! m9es1 ! nature ( ! surr\nd+ rocks is kn[n to "s dep?4 ,imm$iately bel[ ! surface is a decompos$ f]rif]\s basalt1 ab\t #bj to #ij feet 7#f-bg m47 ?ick1 next a black slaty %ale1 #bjj to #bej feet 7#fj-ge m47 ?ick1 !n #aj feet 7#c m47 ( conglom]ate1 next #djj feet 7#abj m47 ( oliv9e diabase1 !n qu>tzite1 ab\t #djj feet 7#abj m47 ?ick1 & la/ly a qu>tz porphyry1 :i* has n yet be5 p5etrat$4 ,! /rata run ne>ly horizontal1 & !re are no signs ( upw>d b5d+ at ! pipes4 ,! :ole ( ! c\ntry1 includ+ ! m9es1 0 cov]$ ) a r$ s&y soil1 & !re 0 no?+ to indicate ! weal? t lay und]nea?4 ,! action ( wat] _h 9 process ( "t remov$ all signs ( eruptive activity4 ,! pr9cipal m9]als :i* are associat$ ) diamond 9 ! blue gr\nd are magnetite1 ilm5ite1 *romic pyrope1 :i* is put on ! m>ket z a gem "u ! misnom] #8,cape-ruby1' f]rif]\s en/atite1 :i* also is sometimes cut1 oliv9e m or less decompos$1 zircon1 kyanite1 & mica4 ,! evid5ce produc$ by an exam9ation ( ! blue gr\nd & ! walls ( ! pipes proves t ! pipes _c h be5 volcanoes su* z ,vesuvius4 ,!re is no indication :atev] ( ! action ( any excessive temp]ature1 :ile1 on ! o!r h&1 !re is e sign ( ! op]ation ( enorm\s pressure2 ! diamonds (t5 conta9 liquid drops ( c>bonic acid4 ,crookes puts =w>d ! plausible !ory t /eam has be5 ! prim>y ag5cy 9 propell+ ! diamond & its associates up into ! *annel ?r\gh :i* x has c>v$ its way to fre$om1 & holds t molt5 iron has be5 ! solv5t = c>bon :i* has cry/alliz$ out z diamond "u ! enorm\s pressures obta9+ 9 remote dep?s ( ! e>?'s cru/4 ,x is p]t95t to note t1 by dissolv+ c>bon 9 molt5 iron1 ! em95t *emi/1 ,moissan1 0 enabl$ to manufacture t9y diamond cry/als4 ,wat] trickl+ d[n f above w\ld be imm$iately conv]t$ into /eam at v high pressure on com+ into contact ) ! molt5 iron1 &1 9 its ef=ts to escape1 ! /eam w\ld drive ! iron & its preci\s cont5ts1 toge!r ) ! adjac5t rocks1 upw>ds to ! surface4 ,! f]rif]\s nature ( ! blue gr\nd & ! yell[ t+e s common to ! diamonds l5d confirmation to ?is !ory4 ,! process by :i* ! c>bon 0 extract$ f %ales or o!r c>bonif]\s rocks & dissolv$ 9 iron /ill awaits elucidation4 ,diamonds 7 f\nd 9 ,new ,s\? ,wales z long ago z #ahea on ,turon ,riv] & at ,re$y ,creek1 ne> ,ba?ur/1 ab\t n9ety miles 7#ade km47 f ,sydney1 b ! f9d 0 ( little comm]cial importance4 ,a m ext5sive deposit came to light 9 #ahfg f>!r nor? at ,mudgee4 ,9 #ahgb diamonds 7 discov]$ 9 ! extreme nor? ( ! ,/ate1 at ,b+>a ne> ! ,que5sl& bord]4 ,ano!r discov]y 0 made 9 #ahhd at ,t+ha1 & /ill m rec5tly 9 ! t9 gravels ( ,inv]ell 9 ! same region4 ,9 _! fre$om f col\r & abs5ce ( tw9n+ ! ,new ,s\? ,wales diamonds resemble ! ,brazilian /ones4 ,! av]age size is small1 runn+ ab\t five to ! c>at :5 cut2 ! l>ge/ f\nd weigh$ ne>ly #f c>ats :5 cut4 ,!y are rem>kable = _! excessive h>dness2 !y c be cut only ) _! own du/1 ord9>y diamond du/ mak+ no impression4 ,! ,borneo diamonds are likewise di/+ui%$ by _! exceptional h>dness4 ,!y mo/ly occur by ! riv] ,l&ak1 ne> ,pontianak on ! we/ coa/ ( ! isl&4 ,!y are f\nd 9 a lay] ( r co>se gravel1 v>iable1 b r>ely exce$+ a y>d 7#a m471 9 dep?1 & are associat$ ) corundum & rutile1 toge!r ) ! preci\s metals gold & plat9um4 ,inde$1 x is no uncommon sight to see natives we>+ wai/coats ornam5t$ ) gold buttons1 9 ea* ( :i* a diamond is set4 ,! diamonds are well cry/alliz$ & g5]ally ( pure wat]2 yell[i% & can>y-yell[ /ones are also common1 b rose-r$1 blui%1 smoky1 & black /ones are r>e4 ,!y seldom exce$ a c>at 9 weight2 b /ones ( #aj c>ats 9 weight are f\nd1 & occasionally !y atta9 to #bj c>ats4 ,9 #ahej a diamond weigh+ #gg c>ats 0 discov]$4 ,! ,rajah ( ,mattan is said to possess "o ( ! pure/ wat] weigh+ z mu* z #cfg c>ats1 b no "o qualifi$ to pron\nce an op9ion reg>d+ its g5u95ess has ev] se5 x4 ,9 ,rhodesia small diamonds h be5 f\nd 9 gravel b$s re/+ on decompos$ granite ne> ! ,somabula =e/1 ab\t #ab miles 7#ai km47 we/ ( ,gwelo1 9 association ) *rysob]yl 9 abundance1 blue topaz1 kyanite1 ruby1 sapphire1 t\rmal9e1 & g>net4 ,! occurr5ce ( diamond 9 ,g]man ,s\?-,we/ ,africa is v peculi>4 ,l>ge numb]s ( small /ones are f\nd close to ! %ore ne> ,lud]itz ,bay 9 a gravelly surface lay]1 :i* is n[h]e m ?an a foot 9 dep?4 ,!y are pick$ by h& by natives & wa%$ 9 sieves4 ,9 %ape !y are g5]ally six-fac$ octah$ra or tw9n$ octah$ra1 simple octah$ra be+ r>e1 & 9 size !y run ab\t f\r or five to ! c>at1 ! l>ge/ /one z yet f\nd be+ only #b c>ats 9 weight4 ,_! col\r is usually yell[i%4 ,sev]al isolat$ f9ds ( diamonds h be5 report$ 9 ,cali=nia & o!r p>ts ( ! ,unit$ ,/ates1 b none h prov$ ( any importance4 ,! l>ge/ /one f\nd weigh$ #bc c>ats uncut2 x 0 discov]$ at ,man*e/] 9 ,virg9ia4 ,,*apt] ,,xviii ,,hi/orical ,,diamonds ,! numb] ( diamonds :i* exce$ a hundr$ c>ats 9 weight :5 cut is v limit$4 ,_! extreme co/l9ess r5d]s !m some?+ m ?an m]e ornam5ts2 9 a cond5s$ & portable =m !y repres5t great weal? & all ! pot5tiality = good or ill !reby entail$1 & h play$ no small1 if s9i/]1 rle 9 ! m\ld+ ( hi/ory4 ,9 bygone days :5 despotic gov]nm5t 0 univ]sal1 ! possession ( a spl5did jewel 9 weak h&s b too (t5 precipitat$ ! aggression ( a gre$y & p[]ful neighb\r1 & plung$ :ole c\ntries into ! horrors ( a ru?less & bloody w>4 ,9 m civiliz$ days a great diamond has (t5 be5 pl$g$ z security = money to repl5i% an empty treasury 9 times ( /ress4 ,! ambitions ( ,napoleon might h receiv$ a set-back b = ! funds rais$ on ! security ( ! fam\s ,pitt diamond4 ,! hi/ory ( su* /ones--(t5 "o long romance--is full ( int]e/1 b space w n p]mit ( m ?an a brief sket* "h4 ,if we except ! colossal ,cull9an /one1 ! m9es ( ,brazil & ,s\? ,africa _c comp>e ) ! old m9es ( ,india z ! bir?place ( l>ge & p]fect diamonds ( _w-wide fame4 7#a7 ,,koh-,i-,,nor ,illu/ration3 ,,fig4 #fa4--,koh-i-nor 7top view74 ,illu/ration3 ,,fig4 #fb4--,koh-i-nor 7side view74 ,! hi/ory ( ! fam\s /one call$ ! ,koh-i-nor1 mean+ ,m\nd ( ,light1 is kn[n z f> back z ! ye> #acjd1 :5 x fell into ! h&s ( ! ,mogul emp]ors1 & leg5d ev5 traces x back "s f\r ?\s& ye>s previ\sly4 ,x rema9$ at ,delhi until ! invasion ( ,nor?-,we/ ,india by ,nadir ,%ah 9 #agci1 :5 x pass$ toge!r ) an imm5se am\nt ( spoil into ! h&s ( ! conqu]or4 ,at 8 dea? ! empire :i* he _h s /r5u\sly f\nd$ fell to pieces1 & ! great diamond aft] _m vicissitudes came into ! possession ( ,runjit ,s+h at ,lahore4 ,8 successors kept x until ^u ! fall ( ! ,sikh p[] 9 #ahej x pass$ to ! ,ea/ ,india ,company1 9 ^: "n x 0 pres5t$ by ,"l ,dalh\sie to ,que5 ,victoria4 ,at ?is date ! /one /ill reta9$ its orig9al ,indian =m1 b 9 #ahfb x 0 re-cut into ! =m ( a %all[ brilliant 7,fig4 #fb71 ! weight !reby be+ r$uc$ f #ahf-a_/af to #ajf-a_/af c>ats4 ,! wisdom ( ?is c\rse has be5 sev]ely criticiz$2 ! /one has n ! correct %ape ( a brilliant & is defici5t 9 #8fire1' & x has ) ! *ange 9 %ape lo/ mu* ( its old hi/orical int]e/4 ,! ,koh-i-nor is ! private prop]ty ( ! ,engli% ,royal ,family1 ! /one %[n 9 ! ,t[] be+ a model4 ,x is valu$ at #ajj1jjj4 7#b7 ,,pitt ,,or ,,reg5t ,illu/ration3 ,,fig4 #fc4--,pitt or ,reg5t 7top view74 ,illu/ration3 ,,fig4 #fd4--,pitt or ,reg5t 7side view74 ,?is spl5did /one 0 discov]$ 9 #agja at ! fam\s diamond m9es at ,p>tial1 on ! ,ki/na1 ab\t #aej miles 7#bdj km47 f ,golconda1 & weigh$ z mu* z #daj c>ats 9 ! r\gh4 ,by devi\s ways x came into ! h&s ( ,jam*und1 a ,p>see m]*ant1 f :om x 0 pur*as$ by ,william ,pitt1 gov]nor ( ,=t ,/4 ,george1 ,madras1 = #bj1djj4 ,on 8 return to ,engl& ,pitt _h x cut into a p]fect brilliant 7,fig4 #fc71 weigh+ #afc c>ats1 ! op]ation occupy+ ! space ( two ye>s & co/+ #ejjj2 m ?an #gjjj is said to h be5 realiz$ f ! sale ( ! fragm5ts left ov]4 ,pitt _h an uneasy "t & liv$ 9 con/ant dread ( !ft ( ! /one until1 9 #agag1 aft] l5g?y negotiations1 he p>t$ ) x to ! ,duc d',orlans1 ,reg5t ( ,france1 = ! imm5se sum ( ?ree & ?ree-qu>t] million francs1 ab\t #ace1jjj4 ,) ! rema9d] ( ! ,fr5* regalia x 0 /ol5 f ! ,g>de-meuble on ,augu/ #ag1 #agib1 9 ! e>ly days ( ! ,fr5* ,revolution1 b 0 ev5tually re/or$ by ! ?ieves1 d\btless because ( ! impossibility ( dispos+ ( su* a /one1 at lea/ intact1 & x is n[ exhibit$ 9 ! ,apollo ,gall]y ( ! ,l\vre at ,p>is4 ,x measures ab\t #cj millimetres 9 l5g?1 #be 9 wid?1 & #ai 9 dep?1 & is valu$ at #dhj1jjj4 7#c7 ,,orl(f ,illu/ration3 ,,fig4 #fe4--,orl(f 7top view74 ,illu/ration3 ,,fig4 #ff4--,orl(f 7side view74 ,"o ( ! f9e/ diamonds exi/+1 ?is l>ge /one =ms ! top ( ! imp]ial sceptre ( ,russia4 ,x is rose-cut 7,fig4 #fe71 ! base be+ a cleavage face1 & weighs #aid c>ats4 ,x is said to h =m$ at "o "t "o ( ! eyes ( a /atue ( ,brahma :i* /ood 9 a temple on ! isl& ( ,%]+ham 9 ! ,cav]y ,riv]1 ne> ,tri*9opoli1 9 ,mysore1 & to h be5 /ol5 by a ,fr5* soldi] :o _h someh[ p]suad$ ! prie/s to appo9t him gu>dian ( ! temple4 ,he sold x = #bjjj to ! capta9 ( an ,engli% %ip1 :o dispos$ ( x to a ,jewi% deal] 9 ,london = #ab1jjj4 ,x *ang$ h&s to a ,p]sian m]*ant1 ,raphael ,khojeh1 :o ev5tually sold x to ,pr9ce ,orl(f =1 s x is said1 ! imm5se sum ( #ij1jjj & an annuity ( #djjj4 ,x 0 pres5t$ by ,pr9ce ,orl(f to ,ca!r9e ,,ii ( ,russia4 7#d7 ,,great ,,mogul ,?is1 ! l>ge/ ,indian diamond kn[n1 0 f\nd 9 ! ,kollur m9es1 ab\t ! ye> #afej4 ,its orig9al weight is said to h be5 #ghg c>ats1 b x 0 s full ( flaws t ! ,v5etian1 ,hort5sio ,borgis1 !n 9 ,india1 9 cutt+ x to a rose =m r$uc$ its weight to #bdj c>ats4 ,x 0 se5 by ,tav]ni] at ! "t ( 8 visit to ,india1 b x has s9ce be5 q lo/ sight (4 ,x has be5 id5tifi$ ) bo? ! ,koh-i-nor & ! ,orl(f1 & x is ev5 sugge/$ t bo? ^! /ones 7 cut f x4 7#e7 ,,sancy ,! hi/ory ( ?is diamond is v involv$1 & probably two or m /ones h be5 confus$4 ,x may h be5 ! "o cut by ,b]quem = ,*>les ! ,bold1 f ^: body on ! fatal day ( ,nancy1 9 #adgg1 x 0 snat*$ by a m>aud+ soldi]4 ,x 0 acquir$ by ,ni*olas ,h>lai1 ,seigneur de ,sancy1 :o sold x to ,que5 ,elizabe? at ! close ( ! sixte5? c5tury4 ,a hundr$ ye>s lat]1 9 #afie1 x 0 sold by ,james ,,ii to ,l\is ,,xiv4 ,! /one 9 ! ,fr5* regalia1 accord+ to ! inv5tory tak5 9 #agia1 weigh$ #ec c>ats4 ,x 0 nev] recov]$ aft] ! !ft ( ! regalia 9 ! foll[+ ye>1 b may be id5tical ) ! diamond :i* 0 9 ! possession ( ! ,demid(f family & 0 sold by ,pr9ce ,demid(f 9 #ahfe to a ,london firm :o 7 said to h be5 act+ = ,sir ,jamsetjee ,jeejeebhoy1 a weal?y ,p>see ( ,bombay4 ,x 0 %[n at ! ,p>is ,exhibition ( #ahfg4 ,x 0 almond-%ap$1 & cov]$ all ov] ) t9y facets by ,indian lapid>ies4 7#f7 ,,great ,,table ,?is my/]i\s /one 0 se5 by ,tav]ni] at ,golconda 9 #afdb1 b has q disappe>$4 ,x weigh$ #bdb-c_/af c>ats4 7#g7 ,,moon ,,( ,,! ,,m\nta9s ,?is diamond is (t5 confus$ ) ! ,orl(f4 ,x 0 captur$ by ,nadir ,%ah at ,delhi1 & aft] 8 murd] 0 /ol5 by an ,afghan soldi] :o dispos$ ( x to an ,arm5ian1 by "n ,%affrass4 ,x 0 f9ally acquir$ by ! ,russian cr[n = an enorm\s sum4 7#h7 ,,nizam ,a l>ge diamond1 weigh+ #cdj c>ats1 belong$ to ! ,nizam ( ,hyd]abad2 x 0 fractur$ at ! beg9n+ ( ! ,indian ,mut9y4 ,:e!r ! weight is t previ\s to fracture or n1 !re seems to be no in=mation4 7#i7 ,,d>ya-,i-,,nor ,?is f9e diamond1 rose-cut & #ahf c>ats 9 weight1 is ( ! pure/ wat] & m]its its title ( #8,riv] ( ,light4' ,x seems to h be5 captur$ by ,nadir ,%ah at ,delhi1 & is n[ ! l>ge/ diamond 9 ! ,p]sian collection4 7#aj7 ,,%ah ,?is f9e /one1 ( ! pure/ wat]1 0 pres5t$ to ! ,cz> ,ni*olas by ! ,p]sian pr9ce ,*osroes1 y\ng] son ( ,abbas ,mirza1 9 #ahdc4 ,at t "t x /ill reta9$ ?ree cleavage faces :i* 7 engrav$ ) ! names ( ?ree ,p]sian sov]eigns1 & weigh$ #ie c>ats4 ,x 01 h[ev]1 subsequ5tly re-cut ) ! loss ( #i c>ats1 & ! engrav+ has disappe>$ 9 ! process4 7#aa7 ,,akb> ,,%ah1 ,,or ,,jehan ,,ghir ,,%ah ,once ! prop]ty ( ! great ,mogul1 ,akb>1 ?is diamond 0 engrav$ on two faces ) ,arabic inscriptions by ! in/ructions ( 8 successor1 ,jehan4 ,x disappe>$1 b turn$ up aga9 9 ,turkey "u ! "n ( #8,%eph]d's ,/one'2 x /ill reta9$ its orig9al inscriptions & 0 !reby recogniz$4 ,9 #ahff x 0 re-cut1 ! weight be+ r$uc$ f #aaf to #ga c>ats1 & ! inscriptions de/roy$4 ,! /one 0 sold to ! ,gaekw> ( ,b>oda = #c lakhs ( rupees 7ab\t #bc1ccc74 7#ab7 ,,pol> ,,/> ,a beautiful1 brilliant-cut /one1 weigh+ #dj c>ats1 :i* is kn[n by ?is "n1 is 9 ! ,russian regalia4 7#ac7 ,,nassak ,! ,nassak diamond1 :i* weigh$ #hi c>ats1 =m$ "p ( ! ,deccan booty1 & 0 put up to auction 9 ,london 9 ,july #ahcg4 ,x 0 pur*as$ by ,emanuel1 a ,london jewell]1 :o = #gbjj %ortly aft]w>ds sold x to ! ,duke ( ,we/m9/]1 9 ^: family x /ill rema9s4 ,x 0 orig9ally pe>-%ap$1 b 0 re-cut to a triangul> =m ) a r$uction 9 weight to #gh c>ats4 7#ad7 ,,napoleon ,?is diamond 0 pur*as$ by ,napoleon ,buonap>te = #hjjj1 & worn by him at 8 w$d+ ) ,joseph9e ,beauh>nais 9 #agif4 7#ae7 ,,cumb]l& ,?is /one1 :i* weighs #cb c>ats1 0 pur*as$ by ! city ( ,london = #aj1jjj & pres5t$ to ! ,duke ( ,cumb]l& aft] ! battle ( ,cullod52 x is n[ 9 ! possession ( ! ,duke ( ,brunswick4 7#af7 ,,pigott ,a f9e ,indian /one1 weigh+ #dg c>ats1 ?is diamond 0 br\ght to ,engl& by ,"l ,pigott 9 #agge & sold = #cj1jjj4 ,x came into ! possession ( ,ali ,pa*a1 ,vic]oy ( ,egypt1 & 0 by 8 ord]s de/roy$ at 8 dea?4 7#ag7 ,,eug,,nie ,?is f9e /one1 weigh+ #ea c>ats1 0 giv5 by ! ,cz>9a ,ca!r9e ,,ii ( ,russia to h] fav\rite1 ,potemk94 ,x 0 pur*as$ by ,napoleon ,,iii z a bridal gift = 8 bride1 & on 8 d[nfall 0 b\ght by ! ,gaekw> ( ,b>oda4 7#ah7 ,,:ite ,,saxon ,squ>e 9 cont\r1 measur+ #a-a_/ab 94 7#bh mm471 & weigh+ #dh c>ats1 ?is /one 0 pur*as$ by ,augu/us ! ,/rong = a million ?al]s 7ab\t #aej1jjj74 7#ai7 ,,pa*a ,,( ,,egypt ,?is #dj-;c>at brilliant 0 pur*as$ by ,ibrahim1 ,vic]oy ( ,egypt1 = #bh1jjj4 7#bj7 ,,/> ,,( ,,e/e ,?\gh a comp>atively small /one1 9 weight #be c>ats1 x is not$ = its p]fection ( =m & quality4 ,x belongs to ! ,ar*duke ,franz ,f]d9& ( ,au/rian-,e/e1 elde/ son ( ! ,ar*duke ,k>l ,ludwig4 7#ba7 ,,tuscany1 ,,or ,,au/rian ,,yell[ ,! beauty ( ?is l>ge /one1 #acc c>ats 9 weight1 is m>r$ by ! t+e ( yell[1 :i* is suffici5tly pron\nc$ to impair its brilliancy2 x is a d\ble rose 9 =m4 ,at "o "t ! prop]ty ( ! ,gr& ,dukes ( ,tuscany1 x is n[ 9 ! possession ( ! ,emp]or ( ,au/ria4 ,k+ m5tions a tale t x 0 b\ght at a curiosity /all 9 ,flor5ce = an insignificant sum1 ! /one be+ suppos$ to be only yell[ qu>tz4 7#bb7 ,,/> ,,( ,,! ,,s\? ,?is1 ! l>ge/ ( ! ,brazilian diamonds1 0 discov]$ at ! m9es ( ,bagagem 9 ,july #ahec4 ,p]fectly transp>5t & )\t t9t1 x 0 dodecah$ral 9 %ape & weigh$ #bed c>ats1 & 0 sold 9 ! r\gh = #dj1jjj4 ,x 0 cut z a p]fect brilliant1 be+ r$uc$ 9 weight to #abe c>ats4 7#bc7 ,,engli% ,,dresd5 ,?is beautiful /one1 :i* weigh$ #aai c>ats 9 ! r\gh1 0 f\nd at ! ,bagagem m9es1 9 ,brazil1 9 #aheg1 & came into ! possession ( ,mr4 ,e4 ,dresd54 ,x 0 cut z a long1 egg-%ap$ brilliant1 weigh+ #gf c>ats4 7#bd7 ,,/> ,,( ,,s\? ,,africa ,! fir/ consid]able /one to be f\nd 9 ,s\? ,africa1 x 0 discov]$ at ! ,vaal ,riv] digg+s 9 #ahfi1 & weigh$ #hc c>ats 9 ! r\gh4 ,x 0 cut to a triangul> brilliant ( #df c>ats4 ,x 0 f9ally pur*as$ by ! ,c\ntess ( ,dudley = #be1jjj4 7#be7 ,,/ew>t ,?is l>ge diamond1 weigh+ 9 ! r\gh #bhh c>ats1 0 f\nd at ! ,vaal ,riv] digg+s 9 #ahgb1 & 0 fir/ sold = #fjjj & %ortly aft]w>ds = #ijjj2 x 0 r$uc$ on cutt+ to #abj c>ats4 ,l _m ,s\? ,african /ones1 x has a fa9t yell[i% t+e4 7#bf7 ,,port]-,,rhodes ,?is blue-:ite /one1 :i* weigh$ #aej c>ats1 0 f\nd 9 a claim belong+ to ,mr4 ,port]-,rhodes 9 ! ,kimb]ley m9e 9 ,febru>y #ahhj4 7#bg7 ,,imp]ial1 ,,victoria1 ,,or ,,great ,,:ite ,?is l>ge diamond weigh$ z mu* z #deg c>ats 9 ! r\gh1 & #ahj :5 cut2 x is q col\rless4 ,x 0 br\ght to ,europe 9 #ahhd1 & 0 ev5tually sold to ! ,nizam ( ,hyd]abad = #bj1jjj4 7#bh7 ,,de ,,be]s ,a pale yell[i% /one1 weigh+ #dbh c>ats1 0 f\nd 9 ! ,de ,be]s m9e 9 #ahhh4 ,x 0 cut to a brilliant weigh+ #bbh c>ats1 & 0 sold to an ,indian pr9ce4 ,a /ill l>g] /one ( simil> t+e1 weigh+ #ejc c>ats1 0 discov]$ 9 #ahif1 & among o!r l>ge /ones suppli$ by ! same m9e may be m5tion$ "o ( #cjb c>ats f\nd 9 #ahhd1 & ano!r ( #dji c>ats f\nd 9 e>ly ye>s4 7#bi7 ,,excelsior ,?is1 :i* prior to ! discov]y ( ! #8,cull9an1' 0 by f> ! l>ge/ ,s\? ,african /one1 0 f\nd 9 ! ,jag]sfonte9 m9e on ,june #cj1 #ahic2 blui%-:ite 9 t9t1 x weigh$ #ifi c>ats4 ,f x 7 cut tw5ty-"o brilliants1 ! l>g] /ones weigh+ #fg1 #de-ac_/af1 #de-aa_/af1 #ci-c_/af1 #cd1 #bg1 #be1 #bc-aa_/af1 #af-aa_/cb1 #ac c>ats respectively1 & ! total weight ( ! cut /ones am\nt+ to #cfd-c_/cb c>ats4 7#cj7 ,,jubilee ,ano!r l>ge /one 0 discov]$ 9 ! ,jag]sfonte9 m9e 9 #ahie4 ,x weigh$ #fcd c>ats 9 ! r\gh1 & f x 0 obta9$ a spl5did1 faultless brilliant weigh+ #bci c>ats4 ,x 0 %[n at ! ,p>is ,exhibition ( #aijj4 7#ca7 ,,/> ,,( ,,africa1 ,,or ,,cull9an ,illu/ration3 ,,fig4 #fg4--;,cull9an ,no4 #a4 ,all diamonds pale into insignificance :5 comp>$ ) ! colossal /one t came to light at ! ,premi] m9e ne> ,pretoria 9 ! ,transvaal on ,janu>y #be1 #aije4 ,x 0 fir/ call$ ! #8,cull9an' aft] ,sir ,t4 ,m4 ,cull9an1 *airman ( ! ,premi] ,diamond ,m9e 7,transvaal7 ,company1 b has rec5tly1 by desire ( ,k+ ,george ,v1 receiv$ ! "n #8,/> ( ,africa4' ,! r\gh /one weigh$ #fbab grams or #cjbe c>ats 7ab\t #a lb472 x display$ ?ree natural faces 7,plate ,,xxv7 & "o l>ge cleavage face1 & its %ape sugge/$ t x 0 a portion ( an enorm\s /one m ?an d\ble its size2 x 0 transp>5t1 col\rless1 & _h only "o small flaw ne> ! surface4 ,?is magnific5t diamond 0 pur*as$ by ! ,transvaal ,gov]nm5t = #aej1jjj1 & pres5t$ to ,k+ ,edw>d ,,vii on 8 bir?day1 ,novemb] #i1 #aijg4 ,illu/ration3 ,,plate ,,xxv ,,cull9an ,,diamond 7,natural size7 ,illu/ration3 ,,fig4 #fh4--;,cull9an ,no4 #b4 ,! ,cull9an 0 entru/$ to ! fam\s firm1 ,messrs4 ,i4 ,j4 ,ass*] ,co41 ( ,am/]dam1 = cutt+ on ,janu>y #bc1 #aijh1 j ?ree ye>s aft] its discov]y4 ,on ,febru>y #aj x 0 cleav$ into two p>ts1 weigh+ respectively #aigg & #ajdj c>ats1 f :i* ! two l>ge/ /ones h be5 cut1 "o be+ a p5deloque or drop brilliant 9 %ape 7,fig4 #fg7 & weigh+ #eaf c>ats1 & ! o!r a squ>e brilliant 7,fig4 #fh7 weigh+ #cji-c_/af c>ats4 ,! fir/ has be5 plac$ 9 ! sceptre1 & ! second 9 ! cr[n ( ! regalia4 ,besides ^! !re are a p5deloque weigh+ #ib c>ats1 a squ>e-%ap$ brilliant #fb1 a he>t-%ap$ /one #ah1 two m>quises #h-i_/af & #aa1 an oblong /one #f1 a p5deloque #d-i_/cb1 & #if small brilliants weigh+ toge!r #g2 ! total weight ( ! cut /ones am\nts to #ajcf-e_/cb c>ats4 ,! l>ge/ /one has #gd & ! second #ff facets4 ,! "w 0 complet$ & ! /ones h&$ to ,k+ ,edw>d 9 ,novemb] #aijh4 ,al?\gh ! ,premi] m9e has yield$ no wor?y compe] ( ! ,cull9an1 x c1 nev]!less1 boa/ ( a consid]able numb] ( l>ge /ones :i* b = comp>ison ) t giant w\ld be ?\ght rem>kable = _! size1 no few] ?an sev5 ( !m hav+ weights ( ov] #cjj c>ats1 viz4 #eaa1 #dhg1 #deh1 #cia1 #cgc1 #cdh1 & #ccd c>ats4 7#cb7 ,,/> ,,( ,,m9as ,?is l>ge diamond1 :i* 0 f\nd 9 #aiaa at ! ,bagagem m9es1 ,m9as ,g]aes1 ,brazil1 _h ! %ape ( a dome ) a flat base1 & weigh$ 9 ! r\gh #cehge grams 7#agd c>ats74 ,! l>ge /one call$ ! #8,braganza1' 9 ! ,portuguese regalia1 :i* is suppos$ to be a diamond1 is probably a :ite topaz2 x weighs #afhj c>ats4 ,! ,mattan /one1 pe>-%ap$ & weigh+ #cfg c>ats1 :i* 0 f\nd 9 ! ,l&ak m9es ne> ! we/ coa/ ( ,borneo 9 #aghg1 is suspect$ to be qu>tz4 ,,col\r$ ,,diamonds 7#a7 ,,hope ,illu/ration3 ,,fig4 #fi4--;,hope4 ,! l>ge/ ( col\r$ diamonds1 ! ,hope1 weighs #dd c>ats1 & has a /eely- or gre5i%-blue1 & n ! royal-blue col\r ( ! glass models suppos$ to repres5t x4 ,x is believ$ to be a portion ( a drop-=m /one 7d'un beau violet7 :i* 0 said to h be5 f\nd at ! ,kollur m9es1 & 0 secur$ by ,tav]ni] 9 ,india 9 #afdb & sold by him to ,l\is ,,xiv 9 #affh2 x !n weigh$ #fg c>ats4 ,?is /one 0 /ol5 ) ! rema9d] ( ! ,fr5* regalia 9 #agib & nev] recov]$4 ,9 #ahcj ! pres5t /one 7,fig4 #fi7 0 (f]$ = sale by ,eliason1 a ,london deal]1 & 0 pur*as$ = #ah1jjj by ,?omas ,philip ,hope1 a weal?y bank] & a ke5 collector ( gems4 ,probably ! apex ( ! orig9al /one _h be5 cut (f1 r$uc+ x to a ne>ly squ>e /one4 ,! slight want ( symmetry ( ! pres5t /one l5ds confirmation to ?is view1 & two o!r blue /ones are kn[n1 :i*1 toge!r ) ! ,hope1 make up ! weight ( ! orig9al /one4 ,at ! sale ( ! ,hope collection at ,*ri/ie's 9 #ahfg ! blue diamond w5t to ,am]ica4 ,9 #aijh ! own] dispos$ ( x to ,habib ,bey = ! enorm\s sum ( #hj1jjj4 ,x 0 put up to auction 9 ,p>is 9 #aiji1 & b\ght by ,ros5au1 ! ,p>is diamond m]*ant1 = ! comp>atively small sum ( #djj1jjj francs 7ab\t #af1jjj71 & 0 sold 9 ,janu>y #aiaa to ,mr4 ,edw>d ,m',lean = #fj1jjj4 ,! /one is suppos$ to br+ ill-luck 9 its tra91 & its hi/ory has be5 lib]ally embelli%$ ) fable to e/abli% ! say+4 7#b7 ,,dresd5 ,a beautiful apple-gre5 diamond1 faultless1 & ( ! pure/ wat]1 is conta9$ 9 ! fam\s ,gre5 ,vaults ( ,dresd54 ,x weighs #dj c>ats1 & 0 pur*as$ by ,augu/us ! ,/rong 9 #agdc = #fj1jjj ?al]s 7ab\t #ijjj74 7#c7 ,,paul ,i ,a f9e ruby-r$ diamond1 weigh+ #aj c>ats1 is includ$ among ! ,russian cr[n jewels4 7#d7 ,,tiffany ,! lovely orange brilliant1 weigh+ #abe c>ats1 :i* is 9 ! possession ( ,messrs4 ,tiffany ,co41 ! well-kn[n jewell]s ( ,new ,york1 0 discov]$ 9 ! ,kimb]ley m9e 9 #ahgh4 ,,*apt] ,,xix ,,corundum 7,sapphire1 ,ruby7 ,rank+ 9 h>dness second to diamond alone1 ! species kn[n to sci5ce z corundum & widely famili> by ! names ( its v>ieties1 sapphire & ruby1 holds a pre-em95t position among col\r$ gem-/ones4 ,! b>b>ic spl5d\r ( ruby 7,plate ,i1 ,fig4 #ac7 & ! glori\s hue ( sapphire 7,plate ,i1 ,fig4 #aa7 are unsurpass$1 & x is rem>kable t ! same species %\ld boa/ su* diff]5t1 b equally magnific5t1 t9ts4 ,!y1 h[ev]1 by no means exhau/ ! res\rces ( ?is v>iegat$ species4 ,f9e yell[ /ones 7,plate ,i1 ,fig4 #ab71 :i* comp>e ) topaz 9 col\r & are its sup]ior 9 h>dness1 & brilliant col\rless /ones1 :i* are un=tunately defici5t 9 #8fire' & _c !re=e approa* diamond1 are to be met )1 besides o!rs ( less attractive hues1 purple1 & yell[i%1 blui%1 & o!r %ades ( gre54 ,want ( homog5eity 9 ! coloration ( corundum is a frequ5t ph5om5on2 ?us1 ! purple /ones on close exam9ation are f\nd to be compos$ ( alt]nate blue & r$ lay]s1 & /ones %[+ pat*es ( yell[ & blue col\r are common4 ,ow+ to ! peculi>ity ( _! int]ior arrangem5t c]ta9 /ones display :5 cut en cabo*on a vivid six-ray$ /> ( light 7,plate ,i1 ,fig4 #ae74 ,sapphire & ruby %>e ) diamond1 pe>l1 & em]ald ! fir/ rank 9 jewell]y4 ,!y are popul> /ones1 especially 9 r+s2 _! comp>ative r>ity 9 l>ge sizes1 ap>t f ! "q ( exp5se1 prev5ts _! use 9 ! bigg] articles ( jewell]y4 ,! front ( ! /ones is usually brilliant-cut & ! back /ep-cut1 b ,indian lapid>ies (t5 pref] to cov] ! /one ) a l>ge numb] ( triangul> facets1 especially if ! /one be flaw$2 />-/ones are cut m or less /eeply en cabo*on4 ,9 composition corundum is alum9a1 oxide ( alum9ium1 correspond+ to ! =mula ,al#b,o#c1 b x usually conta9s 9 addition small quantities1 r>ely m ?an #a p] c5t41 ( f]ric oxide1 *romic oxide1 & p]haps o!r metallic oxides4 ,:5 pure1 x is col\rless2 ! spl5did t9ts :i* are its glory h _! orig9 9 ! m9ute traces ( ! o!r oxides pres5t4 ,no d\bt *romic oxide is ! cause ( ! ruddy hue ( ruby1 s9ce x is possible1 z expla9$ above 7p4 #aag71 closely to imitate ! ruby t9t by ?is means1 b no?+ approa*+ s l>ge a p]c5tage z #b has be5 detect$ 9 a natural /one4 ,! blue col\r ( sapphire may be due to titanic oxide1 & f]ric oxide may be responsible = ! yell[ hue ( ! #8ori5tal topaz1' z ! yell[ corundum is t]m$4 ,sapphires1 :5 ( consid]able size1 are r>ely uni=m 9 t9t ?r\gh\t ! /one4 ,alt]nations ( blue & r$ zones1 giv+ rise to an app>5t purple or violet t9t1 & ! conjunction ( pat*es ( blue & yell[ are common4 ,p]fectly col\rless /ones are less common1 a slight blui% t+e be+ usually noticeable1 b !y are n 9 mu* dem& because1 on acc\nt ( _! lack ( #8fire1' !y are ( little int]e/ :5 cut4 ,! t9t ( ! r$ /ones v>ies consid]ably 9 dep?2 jewell]s t]m !m1 :5 pale1 p9k sapphires1 b1 ( c\rse1 no %>p di/9ction c be drawn betwe5 !m & rubies4 ,! mo/ highly priz$ t9t is ! s-call$ pigeon's blood1 a %ade ( r$ slightly incl9$ to purple4 ,! prices = ruby ( good col\r run f ab\t #bes4 a c>at = small /ones to betwe5 #fj & #hj a c>at = l>ge /ones1 & /ill high] = exceptional rubies4 ,! ta/e 9 sapphires has *ang$ ( rec5t times4 ,=m]ly ! deep blue 0 mo/ 9 dem&1 b n[ ! light] %ade1 t resembl+ ! col\r ( corn-fl[]1 is pref]r$1 because x reta9s a good col\r 9 artificial light4 ,l>ge sapphires are m pl5tiful ?an l>ge rubies1 & prices run l[]2 ev5 = l>ge p]fect /ones ! rate does n exce$ #cj a c>at4 ,l>ge & uni=m #8ori5tal topazes' are comp>atively common1 & realize mod]ate prices1 ab\t #bs4 to #cjs4 a c>at accord+ to quality & size4 ,gre5 sapphires are abundant f ,au/ralia1 b _! t9t1 a k9d ( deep sage-gre51 is n v pleas+4 ,br[n /ones ) a silk9ess ( /ructure are also kn[n4 ,! "n ( ! species comes ?r\gh ! ,fr5* cor9don f an old ,h9du ^w1 korund1 ( unkn[n significance1 & arose f ! circum/ance t ! /ones :i* fir/ f\nd _! way to ,europe came f ,india4 ,at ! pres5t day ! ^w corundum is appli$ 9 comm]ce to ! opaque /ones us$ = abrasive purposes1 to di/+ui% ! pur] mat]ial f em]y1 :i* is corundum mix$ ) magnetite & o!r heavy /ones ( l[] h>dness4 ,! orig9 ( ! ^w sapphire1 :i* means blue1 has be5 discuss$ 9 an e>li] *apt] 7p4 #aaj74 ,jewell]s use x 9 a g5]al s5se = all corundum except ruby4 ,ruby comes f ! ,lat9 rub]1 r$4 ,! prefix #8ori5tal' 7p4 #aaa7 is (t5 us$ to di/+ui% v>ieties ( corundum1 s9ce x is ! h>de/ ( ord9>y col\r$ /ones & ! f9e/ gem-/ones 9 e>ly days rea*$ ,europe by way ( ! ,ea/4 ,corundum cry/allizes ei!r 9 six-sid$ prisms t]m9at$ by flat faces 7,plate ,i1 ,fig4 #aj71 :i* are (t5 triangul>ly m>k$1 or ) twelve incl9$ faces1 six above & six bel[1 meet+ 9 a girdle 7,plate ,i1 ,fig4 #ad74 ,ruby fav\rs ! =m] & ! o!r v>ieties ! latt] type4 ,a f9e cry/al ( ruby--! #8,edw>des1' s nam$ by ! donor1 ,john ,rusk91 aft] ,sir ,h]b]t ,edw>des--:i* weighs #cce grams 7#afc c>ats71 is exhibit$ 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory71 & is tilt$ 9 su* a way t ! light f a neighb\r+ w9d[ falls on ! l>ge basal face1 & reveals ! int]e/+ m>k+s t nature has engrav$ on x4 ,f its type ( symmetry corundum is d\bly refractive ) a direction ( s+le refraction runn+ p>allel to ! edge ( ! prism4 ,ow+ to ! relative purity ( ! *emical composition ! refractive indices are v con/ant2 ! ord9>y index ranges f #agff to #aggd & ! extraord9>y index f #ageg to #agfe1 ! d\ble refraction rema9+ always ! same1 #jjji4 ,! am\nt ( col\r-disp]sion is small1 & !re=e col\rless corundum displays v little #8fire4' ,! diff]5ce betwe5 ! indices = r$ & blue light is1 h[ev]1 suffici5tly great t ! base ( a ruby may be left relatively ?ick] ?an t ( a sapphire to secure an equally satisfactory effect 7cf4 p4 #ih7--;a po9t ( "s importance to ! lapid>y1 s9ce /ones are sold by weight & x is 8 object to keep ! weight z great z possible4 ,:5 a corundum is te/$ on ! refractomet] 9 :ite light a wide spectrum delim9ates ! two portions ( ! field because ( ! smallness ( ! col\r-disp]sion 7cf p4 #be74 ,! di*roism ( bo? ruby & sapphire is m>k$1 ! tw9 col\rs giv5 by ! =m] be+ r$ & purpli%-r$1 & by ! latt] blue & yell[i%-blue1 ! second col\r 9 ea* in/ance correspond+ to ! extraord9>y ray4 ,te/s ) ! di*roscope easily sep>ate ruby & sapphire f any o!r r$ or blue /one4 ,?is "* has an important be>+ on ! prop] mode ( cutt+ ! /ones4 ,! ugly yell[i% t9t giv5 by ! extraord9>y ray ( sapphire %\ld be avoid$ by cutt+ ! /one ) its table-facet at "r angles to ! prism edge1 :i* is ! direction ( s+le refraction4 ,:e!r a ruby %\ld be treat$ 9 ! same way is a moot po9t4 ,no d\bt if ! col\r is deep1 x is ! be/ plan1 because ! am\nt ( absorption ( light is !reby s5sibly r$uc$1 b o!rwise ! delightful nuances di/+ui%+ ruby are be/ secur$ by cutt+ ! table-facet p>allel to ! direction ( s+le refraction4 ,yell[ corundum also %[s di/9ct di*roism1 b by a v>iation m ( ! dep? ?an ( ! t9t ( ! col\r2 ! ph5om5on is fa9t comp>$ ) ! di*roic effect ( a yell[ *rysob]yl4 ,! specific gravity also is v con/ant1 v>y+ only f #cie to #daj2 sapphire is on ! :ole light] ?an ruby4 ,corundum has ! symbol #i on ,mohs's scale1 b ?\gh com+ next to diamond x is a v poor second 7cf4 p4 #gi74 ,z is usually ! case1 ! application ( heat t5ds to light5 ! col\r ( ! /ones3 ^? ( a pale violet or a yell[ col\r lose ! t9t entirely1 & ! deep violet /ones turn a lovely rose col\r4 ,on ! o!r h& ! action ( radium has1 z 0 %[n by ,bordas1 an int5sify+ action on ! col\r1 & ev5 develops x 9 a col\rless /one4 ,f ! latt] reaction x may be inf]r$ t (t5 9 an app>5tly col\rless /one two or m selective influ5ces are at "w :i* ord9>ily neutralize "o ano!r1 b1 be+ unequally /imulat$ by ! action ( radium1 !y !reupon give rise to col\r4 ,! /ellate appe>ance ( a/]ias or />-/ones--/>-ruby & />-sapphire--results f ! regul> arrangem5t ei!r ( num]\s small *annels or ( tw9-lamell 9 ! /one p>allel to ! six sides ( ! prisms2 light is reflect$ f ! int]ior 9 ! =m ( a six-ray$ /> 7p4 #ch74 ,"s /ones f ,siam possess a m>k$ly fibr\s or silky /ructure4 ,! syn!tical manufacture ( ruby1 sapphire1 & o!r v>ieties ( corundum has already be5 describ$ 7p4 #aaf74 ,besides its use 9 jewell]y corundum is on acc\nt ( its h>dness ( great s]vice = _m o!r purposes4 ,small fragm5ts are ext5sively employ$ = ! be>+ p>ts ( ! movem5ts ( wat*es1 & bo? ! opaque corundum & ! impure k9d kn[n z em]y are 9 g5]al use = gr9d+ & poli%+ s(t] /ones1 & /eel & o!r metal-"w4 ,! _w's supply ( f9e rubies is drawn almo/ entirely f ! fam\s ruby m9es ne> ,mogok1 situat$ ab\t #ij miles 7#ade km47 9 a nor?-ea/]ly direction f ,m&alay 9 ,upp] ,burma & at an elevation ( ab\t #djjj ft4 7#abjj m47 above sea-level4 ,x is f ?is di/rict t ! /ones ( ! covet$ c>m9e-r$1 ! s-call$ #8pigeon's blood1' col\r are obta9$4 ,! ruby occurs 9 a granul> lime/one or calcite 9 association ) ! sp9el ( ne>ly ! same appe>ance--! #8balas-ruby1' ori5tal topaz 7yell[ corundum71 t\rmal9e1 & occasionally sapphire4 ,"s /ones are f\nd 9 ! lime/one on ! sides ( ! hills1 b by f> ! l>ge/ quantity occur 9 ! alluvial deposits1 bo? gravel & clay1 9 ! riv]-b$s2 ! ruby gr\nd is locally kn[n z #8byon4' ,! /ones are z a rule q small1 av]ag+ only ab\t f\r to ! c>at4 ,be=e ! ,briti% annexation ( ! c\ntry 9 #ahhe ! m9es 7 a monopoly ( ! ,burmese sov]eigns & 7 work$ solely "u royal lic5ce4 ,!y are kn[n to be ( great antiquity1 b o!rwise _! e>ly hi/ory is a my/]y4 ,x is said t an a/ute k+ secur$ ! priceless t]ritory 9 #aeig f ! neighb\r+ ,*9ese ,%ans 9 ex*ange = a small & unimportant t[n on ! ,irrawaddy2 if t be s1 he /ruck an excell5t b>ga94 ,! m9es 7 allott$ to lic5s$ m9]s1 tw9-tsas 7eat]s ( ! m9e7 z !y 7 call$ 9 ! language ( ! c\ntry1 :o n only paid = ! privilege1 b 7 compell$ to h& ov] to ! k+ all /ones above a c]ta9 weight4 ,z might be anticipat$ ?is injunction caus$ consid]able tr\ble1 & ! royal monopoli/s con/antly suspect$ ! m9]s ( evad+ ! regulation by break+ up /ones ( exceptional size2 f subsequ5t exp]i5ce1 x is probable t l>ge /ones 7 9 reality seldom f\nd4 ,s9ce #ahhg ! m9es h be5 work$ by arrangem5t ) ! ,gov]nm5t ( ,india by ! ,ruby ,m9es1 ,ltd41 an ,engli% company4 ,its c>e] has be5 f> f prosp]\s1 b dur+ rec5t ye>s1 9 consequ5ce ( ! improv$ me?ods ( work+ ! m9es & ( ! m g5]\s t]ms aft]w>ds accord$ by ! ,gov]nm5t1 great] success has be5 exp]i5c$2 ! future is1 h[ev]1 to "s ext5t cl\d$ by ! adv5t ( ! syn!tical /one1 :i* has ev5 made its way out to ! ,ea/4 ,l>ge rubies are f> f common1 & su* z 7 discov]$ 9 ! old days 7 jeal\sly ho>d$ by ! ,burmese sov]eigns4 ,accord+ to ,/reet] ! f9e/ t ev] came to ,europe 7 a pair br\ght ov] 9 #ahge1 at a "t :5 ! ,burmese k+ 0 press$ = money4 ,"o1 ri* 9 col\r1 0 orig9ally cu%ion-%ap$ & weigh$ #cg c>ats2 ! o!r 0 a blunt drop 9 =m & weigh$ #dg c>ats4 ,bo? 7 cut 9 ,london1 ! =m] be+ r$uc$ to #cb-e_/af c>ats & ! latt] to #ch-i_/af c>ats1 & 7 sold = #aj1jjj & #bj1jjj respectively4 ,a colossal /one1 weigh+ #djj c>ats1 is report$ to h be5 f\nd 9 ,burma2 x 0 brok5 into ?ree pieces1 ( :i* two 7 cut & result$ 9 /ones weigh+ #gj & #de c>ats respectively1 & ! ?ird 0 sold uncut 9 ,calcutta = #g lakhs ( rupees 7#df1ffg74 ,! f9d] ( ano!r l>ge /one broke x into two p>ts1 :i* aft] cutt+ weigh$ #ih & #gd c>ats respectively2 he attempt$ 9 va9 to evade ! royal acquisitiv5ess1 by giv+ up ! l>g] /one to ! k+ & conceal+ ! o!r4 ,a f9e /one1 kn[n by ! =midable appellation ( #8,gnaga ,boh' 7,dragon ,"l71 weigh$ #dd c>ats 9 ! r\gh & #bj c>ats aft] cutt+4 ,s9ce ! m9es 7 tak5 ov] by ! ,ruby ,m9es1 ,ltd41 a few l>ge /ones h be5 discov]$4 ,a beautiful ruby 0 f\nd 9 ! ,tag\ngn&a+ ,valley1 & weigh$ #ah c>ats 9 ! r\gh & #aa c>ats aft] cutt+2 p]fectly cle> & ( spl5did col\r1 x 0 sold = #gjjj1 b is n[ valu$ at #aj1jjj4 ,ano!r1 weigh+ #gg c>ats 9 ! r\gh1 0 f\nd 9 #ahii1 & 0 sold 9 ,india 9 #aijd = #d lakhs ( rupees 7#bf1ffg74 ,a /one1 weigh+ #di c>ats1 0 discov]$ 9 #ahhg1 & an enorm\s "o1 weigh+ z mu* z #cjd c>ats1 9 #ahij4 ,! ruby1 z l>ge z a pigeon's egg1 :i* is among/ ! ,russian regalia 0 pres5t$ 9 #aggg to ! ,cz>9a ,ca!r9e by ,gu/av ,,iii ( ,sw$5 :5 on a visit to ,/4 ,pet]sburg4 ,! l>ge r$ /one 9 ! ,engli% regalia :i* 0 suppos$ to be a ruby is a sp9el 7cf p4 #bjf74 ,comp>atively uncommon z sapphires are 9 ! ,burma m9es a faultless /one1 weigh+ z mu* z #gi c>ats1 has be5 discov]$ !re4 ,good rubies1 mo/ly d>k] 9 col\r ?an ! ,burmese /ones1 are f\nd 9 consid]able quantity ne> ,bangkok 9 ,siam1 ,*antabun be+ ! c5tre ( ! trade1 :]e1 j z 9 ,burma1 !y are intimately associat$ ) ! r$ sp9el4 ,because ( ! diff]5ce 9 t9t & ! consequ5t diff]5ce 9 price1 jewell]s draw a di/9ction betwe5 ,burma & ,siam rubies2 b t1 ( c\rse1 does n signify any specific diff]5ce betwe5 !m4 ,siam is1 h[ev]1 mo/ di/+ui%$ z ! orig9al home ( spl5did sapphires4 ,! di/rict ( ,bo ,pie ,r9 9 ,battambang produces1 inde$1 m ?an half ! _w's supply ( sapphires4 ,9 ! ,hills ( ,preci\s ,/ones1 su* be+ ! mean+ ( ! native "n = ! locality1 a numb] ( gre5 corundums are f\nd4 ,siam also produces br[n /ones *>act]iz$ by a peculi> silk9ess ( /ructure4 ,rubies are f\nd 9 ,afghani/an at ! ,amir's m9es ne> ,kabul & also to ! nor? ( ! lapis lazuli m9es 9 ,badak%an4 ,! conditions 9 ,ceylon are precisely ! conv]se ( ^? obta9+ 9 ,burma2 sapphire is pl5tiful & ruby r>e 9 ! isl&4 ,!y are f\nd 9 diff]5t rocks1 sapphire occurr+ ) g>net 9 gneiss1 & ruby accompany+ sp9el 9 lime/one1 b !y come toge!r 9 ! result+ gravels1 ! pr9cipal locality be+ ! gem-di/rict ne> ,ratnapura 9 ! s\? ( ! isl&4 ,! l>ge/ uncut ruby discov]$ 9 ,ceylon weigh$ #db c>ats2 x _h1 h[ev]1 a decid$ t+e ( blue 9 x4 ,ceylon is also not$ = ! magnific5t yell[ corundum1 #8ori5tal topaz1' or1 z x is locally call$1 #8k+ topaz1' :i* x produces4 ,beautiful sapphires occur 9 v>i\s p>ts ( ,india1 b p>ticul>ly 9 ! ,zansk> range ( ! nor?-we/]n ,himalayas 9 ! /ate ( ,ka%mir1 :]e !y are associat$ ) br[n t\rmal9e4 ,probably mo/ ( ! l>ge sapphires kn[n h emanat$ f ,india4 ,by f> ! mo/ gigantic ev] report$ is "o1 weigh+ #iea c>ats1 said to h be5 se5 9 #ahbg 9 ! treasury ( ! ,k+ ( ,ava4 ,! collection at ! ,j>d9 des ,plantes conta9s two spl5did r\gh specim5s2 "o1 kn[n z ! #8,rospoli1' is q flawless & weighs #acb-a_/af c>ats1 & ! o!r is #b in*es 9 l5g? & #a in*es 9 ?ickness4 ,! ,duke ( ,devon%ire possesses a f9e cut /one1 weigh+ #ajj c>ats1 :i* is brilliant-cut above & /ep-cut bel[ ! girdle4 ,an image ( ,buddha1 :i* is cut out ( a s+le sapphire1 is exhibit$1 m\nt$ on a gold p91 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory74 ,= "s ye>s pa/ a l>ge quantity ( sapphires h come into ! m>ket f ,montana1 ,u4,s4,a41 especially f ! gem-di/rict ab\t twelve miles we/ ( ,hel5a4 ,! commone/ col\r is a blui% gre51 g5]ally pale1 b blue1 gre51 yell[ & occasionally r$ /ones are also f\nd2 !y are *>act]iz$ by _! almo/ metallic lu/re4 ,) !m are associat$ gold1 col\rless topaz1 kyanite1 & a beautiful r$ g>net :i* is f\nd 9 gra9s & usually mi/ak5 = ruby4 ,rubies are also f\nd 9 lime/one at ,c[ee ,creek1 ,nor? ,c>ol9a4 ,blue & r$ corundum1 ( r poor quality1 has come f ! ,san>ka ,riv]1 ne> ,troitsk1 & f ,miask1 9 ! ,gov]nm5t ( ,or5burg1 ,russia1 & simil> /ones h be5 kn[n at ,campolongo1 ,/4 ,go?>d1 ,switz]l&4 ,! prolific gem-di/rict ne> ,anakie1 ,que5sl&1 supplies examples ( e kn[n v>iety ( corundum except ruby2 blue1 gre51 yell[1 & p>ti-col\r$ /ones1 & also />-/ones1 are pl5tiful4 ,leaf-gre5 corundum is kn[n fa!r s\?1 9 ,victoria4 ,! ,au/ralian sapphire is too d>k to be ( mu* value4 ,small rubies & sapphires are f\nd 9 ! gem-gravels ne> ! ,somabula ,=e/1 ,rhodesia4 ,,*apt] ,,xx ,,b]yl 7,em]ald1 ,aquam>9e1 ,morganite7 ,! species to be consid]$ 9 ?is *apt] includes ! v>ieties em]ald & aquam>9e1 z well z :at jewell]s und]/& by b]yl4 ,x has _m inconte/able claims on ! att5tion ( all lov]s ( ! beautiful 9 preci\s /ones4 ,! pe]less em]ald 7,plate ,i1 ,fig4 #e71 :i* 9 its v]dant beauty recalls ! exquisite lawns t grace ! c\rts & quadrangles ( our old] seats ( le>n+1 ranks to-day z ! mo/ co/ly ( jewels4 ,its si/] /one1 ! lovely aquam>9e 7,plate ,i1 ,fig4 #d71 :i* seems to h come direct f "s m]maid's treasure-h\se 9 ! dep?s ( a summ] sea1 has *>ms n to be d5i$4 ,pl9y1 speak+ ( ?is species1 truly says1 8,!re is n a col\r m pleas+ to ! eye02 yet he knew only ! comp>atively inf]ior /ones f ,egypt1 & possibly f ! ,ural ,m\nta9s4 ,em]alds are fav\rite r+-/ones1 & w\ld1 no d\bt1 be equally covet$ = l>g] articles ( jewell]y did n ! excessive co/ =bid1 & no?+ c\ld be m attractive = a c5tral /one ?an a *oice aquam>9e ( deep blue-gre5 hue4 ,em]alds are usually /ep-cut1 ?\gh ,indian lapid>ies (t5 fav\r ! en cabo*on =m2 aquam>9es1 on ! o!r h&1 are brilliant-cut 9 front & /ep-cut at ! back4 ,b]yl1 to use ! "n by :i* ! species is kn[n to sci5ce1 is ess5tially a silicate ( alum9ium & b]yllium correspond+ to ! =mula1 ,be#c;,al#b7,si,o#c7f4 ,! b]yllia is (t5 p>tially replac$ by small am\nts ( ! alkal9e e>?s1 caesia1 pota%1 soda1 & li?ia1 v>y+ f ab\t #a p] c5t4 9 b]yl f ,mesa ,gr&e to ne>ly #e 9 t f ,pala & ,madagasc>1 & ov] #f1 ( :i* #cf is caesia1 9 b]yl f ,hebron1 ,ma9e2 also1 z usual1 *romic & f]ric oxides take ! place ( a little alum9a2 f #a to #b p] c5t4 ( wat] has be5 f\nd 9 em]ald4 ,! elem5t b]yllium 01 z its "n sugge/s1 fir/ discov]$ 9 a specim5 ( ?is species1 ! discov]y be+ made 9 #agih by ! *emi/ ,vauquel92 x is also kn[n z gluc9um 9 allusion to ! sweet ta/e ( its salts4 ,:5 pure1 b]yl is col\rless1 b x is r>ely1 if ev]1 free f a t+e ( blue or gre54 ,! col\r is usually "s %ade ( gre5--grass-gre51 ( t *>act]i/ic t9t :i* is 9 consequ5ce kn[n z em]ald-gre51 or blue-gre51 yell[i% gre5 7,plate ,i1 ,fig4 #f71 & sometimes yell[1 p9k1 & rose-r$4 ,! peculi> col\r ( em]ald is suppos$ to be caus$ by *romic oxide1 small quantities ( :i* h be5 detect$ 9 x by *emical analysis2 moreov]1 exp]im5t %[s t glass conta9+ ! same p]c5tage am\nt ( *romic oxide assumes ! same spl5did hue4 ,em]ald1 on be+ heat$1 loses wat]1 b reta9s its col\r unimpair$1 :i* _c !re=e be due1 z has be5 sugge/$1 to organic matt]4 ,! t]m aquam>9e is appli$ to ! deep sea-gre5 & blue-gre5 /ones1 & jewell]s re/rict ! t]m b]yl to pal] %ades & g5]ally o!r col\rs1 su* z yell[1 gold51 & p9k1 b ,kunz has rec5tly propos$ ! "n morganite to di/+ui% ! beautiful rose b]yl su* z is f\nd 9 ,madagasc>4 ,! v>y+ %ades ( aquam>9e are due to ! influ5ce ( ! alkal9e e>?s modifi$ by ! pres5ce ( f]ric oxide or *romic oxide2 ! beautiful blu%+ hue ( morganite is no d\bt caus$ by li?ia4 ,illu/ration3 ,,fig4 #gj4--;,em]ald ,cry/al4 ,! "n ( ! species is d]iv$ f ! ,greek 1 an anci5t ^w1 ! mean+ ( :i* has be5 lo/ 9 ! mi/s ( "t4 ,! ,greek ^w d5ot$ ! same species 9 "p z t n[ und]/ood by ! "n4 ,em]ald is d]iv$ f a ,p]sian ^w :i* appe>$ 9 ,greek z 1 & 9 ,lat9 z sm>agdus2 x orig9ally d5ot$ *rysocolla1 or simil> gre5 /one1 b 0 transf]r$ ^u ! introduction ( ! deep-gre5 b]yl f ,upp] ,egypt4 ,! "n aquam>9e 0 sugge/$ by ,pl9y's exce$+ly happy description ( ! /ones 8:i* imitate ! gre5ness ( ! cle> sea10 al?\gh x 0 n actually us$ by him4 ,t em]ald & b]yl 7 "o species 0 suspect$ by ,pl9y1 b ! id5tity 0 n def9itely e/abli%$ till ab\t a c5tury ago4 ,morganite is nam$ aft] ,john ,pi]pont ,morgan4 ,! natural cry/als h ! =m ( a six-sid$ prism1 & 9 ! case ( em]ald 7,fig4 #gj1 & ,plate ,i1 ,fig4 #h7 inv>iably1 if :ole1 end 9 a s+le face at "r angles to ! l5g? ( ! prism2 aquam>9es h 9 addition a numb] ( small incl9$ faces1 & /ones f bo? ,russia & ,brazil (t5 tap] ow+ to ! effects ( corrosion4 ,! sixfold "* ( ! cry/all9e symmetry necess>ily entails t ! d\ble refraction1 :i* is small 9 am\nt1 #jjjf1 is uniaxial 9 "*1 &1 s9ce ! ord9>y is great] ?an ! extraord9>y refractive index1 x is negative 9 sign4 ,! values ( ! indices range betwe5 #aefg & #aeij1 & #aegb & #aeih respectively1 9 ! two cases1 ! p9k b]yl possess+ ! highe/ values4 ,! di*roism is di/9ct 9 ! ,s\? ,am]ican em]ald1 ! tw9 col\rs be+ yell[i% & blui% gre51 b o!rwise is r fa9t4 ,! specific gravity v>ies betwe5 #bfi & #bgi1 & is !re=e a little high] ?an t ( qu>tz4 ,if1 !re=e1 a b]yl & a qu>tz be float+ toge!r 9 a tube conta9+ a suitable heavy liquid1 ! =m] w always be at a s5sibly l[] level 7cf4 ,fig4 #cb74 ,! h>dness v>ies f #g to #h1 em]ald be+ a little s(t] ?an ! o!r v>ieties4 ,!re is no cleavage1 b l mo/ gem-/ones b]yl is v brittle1 & c easily be fractur$4 ,/ones r5d]$ cl\dy by fissures are t]m$ #8mossy4' ,:5 heat$ be=e ! bl[pipe b]yl is fusible ) difficulty2 x resi/s ! attack ( hydr(luoric acid z well z ( ord9>y acids4 ,9 all probability ! :ole ( ! em]alds kn[n 9 anci5t times came f ! s-call$ ,cleopatra em]ald m9es 9 ,upp] ,egypt4 ,= "s reason !y 7 ab&on$1 & _! position 0 s completely lo/ t 9 ! ,middle ,ages x 0 ma9ta9$ t em]alds _h nev] be5 f\nd 9 ,egypt at all1 b _h come f ,am]ica by way ( ! ,ea/4 ,all d\bts 7 set at re/ by ! re-discov]y ( ! m9es e>ly la/ c5tury by ,cailliaud1 :o _h be5 s5t by ! ,vic]oy ( ,egypt to se>* = !m4 ,!y 71 h[ev]1 n mu* work$1 & aft] a few ye>s 7 clos$ aga91 & 7 re-op5$ only ab\t t5 ye>s ago4 ,! pr9cipal m9es are at ,jebel ,zab>a & at ,jebel ,sikait 9 nor!rn ,etbai1 ab\t #aj miles 7#af km47 ap>t & di/ant ab\t #ae miles 7#bd km47 f ! ,r$ ,sea1 ly+ 9 ! range ( m\nta9s t run = a long di/ance p>allel to ! we/ coa/ ( ! ,r$ ,sea & rise to ov] #ahjj feet 7#eej m47 above sea-level4 ,!re are num]\s signs ( consid]able1 b primitive1 work+s at di/9ct p]iods4 ,bo? em]alds & b]yls are f\nd 9 micace\s & talcose s*i/s4 ,! em]alds are n ( v good quality1 be+ cl\dy & r light 9 col\r4 ,f9] em]alds h be5 f\nd 9 a d>k mica-s*i/1 toge!r ) o!r b]yllium m9]als1 *rysob]yl & ph5akite1 & also topaz & t\rmal9e on ! ,asiatic side ( ! ,ural ,m\nta9s1 ne> ! ,tak[aja ,riv]1 :i* fl[s into ! ,bol%oi ,reft ,riv]1 "o ( ! l>g] tribut>ies ( ! ,pys*ma ,riv]1 ab\t fifty miles 7#hj km47 ea/ ( ,ekat]9burg1 a t[n :i* is *iefly conc]n$ ) ! m9+ & cutt+ ( gem-/ones4 ,! m9e 0 accid5tally discov]$ by a peasant1 :o notic$ a few gre5 /ones at ! foot ( an uproot$ tree 9 #ahcj4 ,two ye>s lat] ! m9e 0 regul>ly work$1 & rema9$ op5 = tw5ty ye>s1 :5 x 0 clos$4 ,x has rec5tly be5 re-op5$ ow+ to ! high rates obta9+ = em]alds4 ,v l>ge cry/als h be5 produc$ "h1 b 9 col\r !y are mu* inf]ior to ! ,s\? ,am]ican /ones2 small ,sib]ian em]alds1 on ! o!r h&1 are ( bett] col\r ?an small ,s\? ,am]ican em]alds1 ! latt] be+ n s deep 9 t9t4 ,em]alds h be5 f\nd 9 a simil> k9d ( s*i/ at ,haba*tal1 9 ! ,salzburg ,alps4 ,ab\t ?irty ye>s ago well-=m$ gre5 /ones 7 discov]$ ) hidd5ite at ,/ony ,po9t1 ,alex&] ,c\nty1 9 ,nor? ,c>ol9a1 b n mu* gem mat]ial has come to light4 ,! products ( none ( ! m9es t h j be5 m5tion$ c on ! :ole comp>e ) ! beautiful /ones :i* h come f ,s\? ,am]ica4 ,at ! "t :5 ! ,spani>ds grimly conqu]$ ,p]u & ru?lessly despoil$ ! c\ntry ( ! treasures :i* c\ld be c>ri$ away1 imm5se numb]s ( em]alds--"s ( almo/ incr$ible size--7 lit]ally p\r$ into ,spa91 & ev5tually f\nd _! way to o!r p>ts ( ,europe4 ,^! /ones 7 kn[n z ,spani% or ,p]uvian em]alds1 b 9 all probability none ( !m 7 actually m9$ 9 ,p]u4 ,p]haps ! mo/ extraord9>y 7 ! five *oice /ones :i* ,cortez pres5t$ to 8 bride1 ! niece ( ! ,duke de ,bej>1 !reby mortally (f5d+ ! ,que51 :o _h desir$ !m = h]self1 & :i* 7 lo/ 9 #aebi :5 ,cortez 0 %ipwreck$ on 8 disa/r\s voyage to assi/ ,*>les ,v at ! siege ( ,algi]s4 ,all five /ones _h be5 work$ to div]s fanta/ic %apes4 ,"o 0 cut l a bell ) a f9e pe>l = a tongue1 & bore on ! rim1 9 ,spani%1 8,bless$ is he :o creat$ !e40 ,a second 0 %ap$ l a rose1 & a ?ird l a horn4 ,a f\r? 0 fa%ion$ l a fi%1 ) eyes ( gold4 ,! fif?1 :i* 0 ! mo/ valuable & ! mo/ rem>kable ( all1 0 holl[$ out into ! =m ( a cup1 & _h a foot ( gold2 its rim1 :i* 0 =m$ ( ! same preci\s metal1 0 engrav$ ) ! words1 8,int] natos muli]um non surrexit major40 ,z soon z ! ,spani>ds _h seiz$ ne>ly all ! em]alds t ! natives _h amass$ 9 _! temples or = p]sonal adornm5t1 !y devot$ _! att5tion to se>*+ = ! s\rce ( ^! m>vels ( nature1 & ev5tually 9 #aeeh !y light$ by accid5t ^u ! m9es 9 :at is n[ ! ,unit$ ,/ates ( ,colombia1 :i* h be5 work$ almo/ cont9u\sly s9ce t "t4 ,s9ce ! natives1 :o naturally res5t$ ! gross inju/ice ) :i* !y _h be5 treat$1 & p5etrat$ ! gre$ t prompt$ ! actions ( ! ,spani>ds1 hid all traces ( ! m9es1 & refus$ to give any in=mation z to _! position1 x is possible t o!r em]ald m9es may yet be f\nd4 ,! pres5t m9es are situat$ ne> ! village ( ,muzo1 ab\t #ge miles 7#abj km47 nor?-nor?-we/ ( ,bogota1 ! capital ( ,colombia4 ,! em]alds occur 9 calcite ve9s 9 a bitum9\s lime/one ( ,cretace\s age4 ,! ,spani>ds =m]ly work$ ! m9es by driv+ adits ?r\gh ! b>r5 rock on ! hillsides to ! gem-be>+ ve9s1 b at ! pres5t day ! op5 cut me?od ( work+ is employ$4 ,a pl5tiful supply ( wat] is available1 :i* is accumulat$ 9 res]voirs & all[$ at ! prop] "t to sweep ! debris ( b>r5 rock away into ! ,rio ,m9]o1 leav+ ! rock conta9+ ! em]alds expos$4 ,/ones1 ( good quality1 :i* are suit$ = cutt+1 are locally kn[n z canutillos1 inf]ior /ones1 co>se or ill-%ap$1 be+ call$ morallons4 ,em]ald1 unlike "s gre5 /ones1 reta9s its purity ( col\r 9 artificial light2 9 fact1 to quote ! words ( ,pl9y1 8,= nei!r sun nor %ade1 nor yet ! light ( c&le1 cause? to *ange & lose _! lu/re40 ,_m are ! sup]/itions t h be5 atta*$ to x4 ,?us x 0 suppos$ to be good = ! eyes1 & z ,pl9y says1 8,besides1 !re is n a gem or preci\s /one t s fully possesse? ! eye1 & yet nev] cont5te? x ) satiety4 ,nay1 if ! sight ha? be5 we>i$ & dimm$ by int5tive por+ ^u any?+ else1 ! behold+ ( ?is /one do? refre% & re/ore x aga940 ,! idea t x 0 fatal to ! eyesight ( s]p5ts appe>s 9 ,moore's l9es-- 8,bl9d$ l s]p5ts :5 !y gaze ,^u ! em]ald's virg9 blaze40 ,! cry/als occur atta*$ to ! lime/one1 & are !re=e nev] f\nd d\bly t]m9at$4 ,! cry/al =m is v simple1 m]ely a hexagonal prism ) a flat face at ! "o end at "r angles to x4 ,!y are inv>iably flaw$1 s mu* s t a flawless em]ald has pass$ into prov]b z unatta9able p]fection4 ,! l>ge/ s+le cry/al :i* is kn[n to exi/ at ! pres5t day is 9 ! possession ( ! ,duke ( ,devon%ire 7,fig4 #ga74 ,9 section x is ne>ly a regul> hexagon1 ab\t #b in*es 7#ea mm47 9 diamet] f side to side1 & ! l5g? is ab\t ! same2 its weight is #bgfgi grams 7#i oz4 ,av41 or #acdg c>ats74 ,x is ( good col\r1 b badly flaw$4 ,x 0 giv5 to ! ,duke ( ,devon%ire by ,dom ,p$ro ( ,brazil1 & 0 exhibit$ at ! ,great ,exhibition ( #ahea4 ,a f9e1 ?\gh mu* small] cry/al1 b ( ev5 bett] col\r1 :i* weighs #cbb grams 7#aef c>ats71 & measures #a in* 7#bh mm47 9 its wide/ cross-diamet]1 & ab\t ! same 9 l5g?1 0 acquir$ ) ! ,allan-,greg collection by ! ,briti% ,museum1 & is exhibit$ 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory74 ,! f9e/ cut em]ald is said to be "o weigh+ #cj c>ats1 :i* belongs to ! ,cz> ( ,russia4 ,a small1 b p]fect & flawless1 facet$ em]ald1 :i* is set 9 a gold hoop1 is also 9 ! ,briti% ,museum 7,natural ,hi/ory74 ,x is %[n1 )\t ! sett+1 ab\t actual size1 on ,plate ,i1 ,fig4 #e4 ,illu/ration3 ,,fig4 #ga4--;,duke ( ,devon%ire's ,em]ald4 7,natural size47 ,! ev] great dem& & ! ess5tially re/rict$ supply h =c$ ! co/ ( em]alds ( good quality to a height t puts l>ge /ones beyond ! rea* ( all b a privileg$ few :o h purses deep en\gh4 ,! rate p] c>at may be any?+ f #ae upw>ds1 dep5d+ ^u ! purity ( ! col\r & ! fre$om f flaws1 b x increases v rapidly ) ! size1 s9ce flawless /ones ( m ?an #d c>ats or s 9 weight are among ! r>e/ ( jewels2 a p]fect em]ald ( #d c>ats may easily fet* #afjj to #bjjj4 ,x seems anomal\s to say t x has nev] be5 easi] to procure f9e /ones ?an dur+ rec5t ye>s1 b ! reason is t ! high prices prevail+ h tempt$ own]s ( old jewell]y to realize _! em]alds4 ,on ! o!r h&1 pale em]alds are wor? only a nom9al sum4 ,! o!r v>ieties ( b]yl are mu* less r>e1 &1 s9ce !y usually atta9 to m consid]able1 & sometimes ev5 colossal1 size1 f> l>g] /ones are obta9able4 ,an aquam>9e1 p>ticul>ly ( good deep blue-gre5 col\r1 is a /one ( great beauty1 & x possesses ! m]it ( pres]v+ its purity ( t9t 9 artificial light4 ,x is a fav\rite /one = p5dants1 broo*es1 & bracelets1 & all purposes = :i* a l>ge blue or gre5 /one is desir$4 ,! v>y+ t9ts are said to be due to ! pres5ce ( iron 9 diff]5t p]c5tages1 & possibly 9 diff]5t /ates ( oxidation4 ,unlike em]ald1 ! o!r v>ieties are by no means s easily recogniz$ by _! col\r4 ,blue aquam>9es may easily be mi/ak5 = topaz1 or vice v]sa1 & ! yell[ b]yl closely resembles o!r yell[ /ones1 su* z qu>tz1 topaz1 or t\rmal9e4 ,/ones :i* are col\rless or only slightly t9t$ comm& little m ?an ! price ( cutt+1 b ! price ( blue-gre5 /ones rapidly advances ) increas+ dep? ( t9t up to #b a c>at4 ,! enorm\s cut aquam>9e :i* is exhibit$ 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory71 af=ds "s idea ( ! great size su* /ones rea*2 a beautiful sea-gre5 9 col\r1 x weighs #agie grams 7#hge c>ats71 & is table-cut ) an oval cont\r4 ,! spl5did six-sid$ columns :i* h be5 discov]$ 9 v>i\s p>ts ( ,sib]ia are among ! mo/ /rik+ specim5s 9 any l>ge m9]al collection4 ,! neighb\rhood ( ,ekat]9burg 9 ! ,urals is prolific 9 v>ieties ( aquam>9e2 especially at ,murs9ka h f9e /ones be5 f\nd1 9 association ) topaz1 ame?y/1 & s*orl1 ! black t\rmal9e4 ,good /ones also occur 9 conjunction ) topaz at ,miask 9 ! ,gov]nm5t ( ,or5burg4 ,x is f\nd 9 ! gold-wa%+s ( ! ,san>ka ,riv]1 9 ! ,s\!rn ,urals1 b ! /ones are n fitt$ = s]vice z gems4 ,magnific5t blue-gre5 & yell[ aquam>9es are associat$ ) topaz & smoky qu>tz 9 ! granite ( ! ,adun-,ts*ilon ,m\nta9s1 ne> ,n]ts*9sk1 ,transbaikal4 ,/ones h also be5 f\nd at ! ,urulga ,riv] 9 ,sib]ia4 ,mo/ ( ! blui%-gre5 aquam>9es :i* come into ! m>ket at ! pres5t "t h orig9at$ 9 ,brazil1 p>ticul>ly 9 ,m9as ,novas1 ,m9as ,g]aes1 :]e cle>1 transp>5t /ones1 ( pleas+ col\r1 9 v>i\s %ades1 are f\nd 9 ! utmo/ pr(usion2 beautiful yell[ /ones also occur at ! ,bahia m9es4 ,aquam>9e 0 obta9$ 9 v e>ly times 9 ,coimbatore ,di/rict1 ,madras1 ,india1 & yell[ b]yl comes f ,ceylon4 ,f9e blue cry/als occur 9 ! granite ( ! ,m\rne ,m\nta9s1 ,irel&1 b !y are n cle> en\gh = cutt+ purposes2 simil> /ones are f\nd also at ,limoges1 ,haute ,vi5ne1 ,france4 ,aquam>9es ( v>i\s hues ab\nd 9 sev]al places 9 ! ,unit$ ,/ates1 among ! pr9cipal localities be+ ,/oneham 9 ,ma9e1 ,haddam 9 ,connecticut1 & ,pala & ,mesa ,gr&e 9 ,san ,diego ,c\nty1 ,cali=nia4 ,! la/-nam$ /ate is rem>kable = ! num]\s /ones ( v>y+ dep? ( salmon-p9k t h be5 f\nd !re4 ,x is1 h[ev]1 surpass$ by ,madagasc>1 :i* has rec5tly produc$ spl5did /ones ( p]fect rose-r$ t9t & ( ! f9e/ gem quality1 "s ( !m be+ ne>ly #ajj c>ats 9 weight4 ,^! /ones1 :i* h be5 assign$ a special "n1 morganite 7cf4 supra71 are associat$ ) t\rmal9e & kunzite4 ,p9k & yell[ b]yls & deep blue-gre5 aquam>9es occur 9 ! isl& 9 quantity4 ,! p9k b]yls f ,cali=nia are g5]ally pale or h a pron\nc$ salmon t9t1 & seldom approa* ! real rose-r$ col\r ( morganite2 "o magnific5t rose-r$ cry/al1 weigh+ ne>ly #i lb4 7#dje kg471 has1 h[ev]1 be5 rec5tly discov]$ 9 ,san ,diego ,c\nty1 ,cali=nia1 & is n[ 9 ! ,briti% ,museum 7,natural ,hi/ory74 ,blue-gre5 b]yl1 v>y+ 9 t9t f almo/ col\rless to an em]ald-gre51 occurs ) t9-/one & topaz ab\t #i miles 7#ad km47 nor?-ea/ ( ,emmaville 9 ,new ,s\? ,wales1 ,au/ralia4 ,probably ! l>ge/ & f9e/ aquam>9e cry/al ev] se5 0 "o f\nd by a m9] on ,m>* #bh1 #aiaj1 at a dep? ( #ae ft4 7#e m47 9 a pegmatite ve9 at ,m>ambaya1 ne> ,arassuahy1 on ! ,jequit9honha ,riv]1 ,m9as ,g]aes1 ,brazil4 ,x 0 gre5i% blue 9 col\r1 & a slightly irregul> hexagonal prism1 ) a flat face at ea* end1 9 =m2 x measur$ #ai 94 7#dhe cm47 9 l5g? & #af 94 7#da cm47 9 diamet]1 & weigh$ #bdc lb4 7#aaje kg472 & its transp>5cy 0 s p]fect t x c\ld be se5 ?r\gh f end to end 7,plate ,,xxvi74 ,! cry/al 0 transport$ to ,bahia1 & sold = #be1jjj 7#eacc74 ,illu/ration3 ,,plate ,,xxvi ,,l>ge ,,aquam>9e ,,cry/al 7"o-six? natural size71 ,,f\nd ,,at ,,m>ambaya1 ,,m9as ,,g]aes1 ,,brazil ,,"p ,,ii--,,section ,b ,,semi-,,preci\s ,,/ones ,,*apt] ,,xxi ,,topaz ,topaz is ! mo/ popul> yell[ /one 9 jewell]y1 & (t5 =ms ! pr9cipal /one 9 broo*es or p5dants1 especially 9 old-fa%ion$ articles4 ,x is a g5]al idea t all yell[ /ones are topazes1 & all topazes are yell[2 b nei!r /atem5t is correct4 ,a v l>ge numb] ( yell[ /ones t masqu]ade z topaz are really ! yell[ qu>tz kn[n z citr9e4 ,! latt] is1 inde$1 almo/ univ]sally call$ by jewell]s topaz1 ! qualification #8,brazilian' be+ us$ by !m to di/+ui% ! true topaz4 ,_m species besides ^? m5tion$ yield yell[ /ones4 ,?us corundum includes ! beautiful #8ori5tal topaz' or yell[ sapphire1 & yell[ t\rmal9es are occasionally met )2 ! yell[ *rysob]yl always has a gre5i% t+e4 ,topaz is g5]ally brilliant-cut 9 front & /ep-cut at ! back1 & ! table facet is sometimes r\nd$1 b ! col\rless /ones are (t5 cut z small brilliants2 x takes an excell5t & dazzl+ poli%4 ,topaz is a silicate ( alum9ium correspond+ to ! =mula ,al7,f1,,oh7#b,si,o#d1 :i* 0 e/abli%$ 9 #ahid by ,p5field & ,m9or z ! result ( c>eful rese>*4 ,contr>y to ! g5]al idea1 topaz is usually col\rless or v pale 9 t9t4 ,yell[ hues ( diff]5t degrees1 f pale to a ri* %]ry t9t 7,plate ,i1 ,fig4 #i71 are common1 & pure pale blue 7,plate ,i1 ,fig4 #g7 & pale gre5 /ones1 :i* (t5 pass z aquam>9e1 are f> f r>e4 ,natural1 r$ & p9k1 /ones are v seldom to be met )4 ,x is1 h[ev]1 a peculi>ity ( ! br[ni%-yell[ /ones f ,brazil t ! col\r is alt]$ by heat+ to a lovely rose-p9k4 ,curi\sly1 ! t9t is n app>5t :5 ! /one is hot1 b develops z x cools to a normal temp]ature2 ! col\r seems to be p]man5t4 ,su* /ones are common 9 mod]n jewell]y4 ,al?\gh ! *ange 9 col\r is accompani$ by "s slight re>rangem5t ( ! con/itu5t molecules1 s9ce su* /ones are inv>iably *>act]iz$ by high refraction & pron\nc$ di*roism1 ! cry/all9e symmetry1 h[ev]1 rema9+ unalt]$1 ! cause mu/ be attribut$ to "s *ange 9 ! t9ctorial ag5t1 probably oxidation4 ,! yell[ /ones f ,ceylon1 if treat$ 9 a simil> mann]1 lose _! col\r entirely4 ,! pale yell[-br[n /ones f ,russia fade on prolong$ exposure to /rong sunlight1 = :i* reason ! sup]b suite ( cry/als f ! ,urulga ,riv]1 :i* came ) ! ,kok%>ov collection to ! ,briti% ,museum1 are kept "u cov]4 ,! "n ( ! species is d]iv$ f topazion 71 to seek71 ! "n giv5 to an isl& 9 ! ,r$ ,sea1 :i* 9 old5 times 0 ) difficulty locat$1 b x 0 appli$ by ,pl9y & 8 contempor>ies to ! yell[i% p]idot f\nd !re4 ,! t]m 0 appli$ 9 ! ,middle ,ages loosely to any yell[ /one1 & 0 gradually appli$ m p>ticul>ly to ! /one t 0 !n m preval5t1 ! topaz ( mod]n sci5ce4 ,z has already be5 po9t$ out 7p4 #aaa71 ! t]m is /ill employ$ 9 jewell]y to signify any yell[ /one4 ,! true topaz 0 probably includ$ by ,pl9y "u ! "n *rysoli?us4 ,illu/ration3 ,,fig4 #gb4--,topaz ,cry/al4 ,! symmetry is or?orhombic1 & ! cry/als are prismatic 9 %ape & t]m9at$ by num]\s incl9$ faces1 & usually by a l>ge face p]p5dicul> to ! prism edge 7,fig4 #gb74 ,topaz cleaves ) great read9ess at "r angles to ! prism edge2 ow+ to its facile cleavage1 flaws are easily />t$1 & caution mu/ be ex]cis$ n to damage a /one by knock+ x aga9/ h>d & unyield+ sub/ances4 ,! di*roism ( a yell[ topaz is always p]ceptible1 "o ( ! tw9 col\rs be+ di/9ctly m r$di% ?an ! o!r1 & ! ph5om5on is v m>k$ 9 ! case ( /ones ! col\r ( :i* has be5 artificially alt]$ to p9k4 ,! values ( ! lea/ & ! greate/ ( ! pr9cipal indices ( refraction v>y f #afae to #afbi1 & f #afbe to #afcg1 respectively1 ! d\ble refraction be+ ab\t #jjaj 9 am\nt1 & positive 9 sign4 ,! high values correspond to ! alt]$ /ones4 ,! specific gravity1 ! mean value ( :i* is #cee ) a v>iation ( #jje on ei!r side1 is high] ?an w\ld be expect$ f ! refractivity4 ,a cleavage flake exhibits 9 conv]g5t pol>iz$ light a wide-angl$ biaxial picture1 ! #8eyes' ly+ outside ! field ( view4 ,! relation ( ! pr9cipal optical directions & ! directions ( s+le refraction to ! cry/al are %[n 9 ,fig4 #bg4 ,! h>dness is #h on ,mohs's scale1 & 9 ?is "* x is surpass$ only by *rysob]yl1 corundum1 & diamond4 ,topaz is pyro-electric1 9 :i* respect t\rmal9e alone exce$s x1 & x may be /rongly electrifi$ by friction4 ,al?\gh ! range ( refraction ov]laps t ( t\rmal9e1 !re is no risk ( confusion1 because ! latt] has ne>ly ?rice ! am\nt ( d\ble refraction 7cf4 p4 #bi74 ,ap>t f ! diff]5ce 9 refraction1 a yell[ topaz ought nev] to be confus$ ) a yell[ qu>tz1 because ! =m] s9ks1 & ! latt] floats 9 me?yl5e iodide4 ,! same te/ di/+ui%es topaz f b]yl1 &1 inde$1 f t\rmal9e also4 ,judg$ by ! crit]ion ( price1 topaz is n 9 ! fir/ rank ( preci\s /ones4 ,/ones ( good col\r & free f flaws are n[1 h[ev]1 sc>ce4 ,pale /ones are wor? v little1 possibly less ?an #ds4 a c>at1 b ! price rapidly advances ) increase 9 col\r1 rea*+ #bjs4 = yell[1 #hjs4 = p9k & blue /ones4 ,s9ce topazes are procurable 9 all sizes cu/om>y 9 jewell]y1 ! rates v>y b slightly1 if at all1 ) ! size4 ,topaz occurs pr9cipally 9 pegmatite dykes & 9 cavities 9 granite1 & is int]e/+ to petrologi/s z a conspicu\s in/ance ( ! result ( ! action ( hot acid vap\rs ^u rocks ri* 9 alum9ium silicates4 ,magnific5t cry/als h come f ! ext5sive m9+ di/rict :i* /ret*es along ! ea/]n flank ( ! ,ural ,m\nta9s1 & f ! important m9+ region surr\nd+ ,n]ts*9sk1 9 ! ,gov]nm5t ( ,transbaikal1 ,sib]ia4 ,f9e gre5 & blue /ones h be5 f\nd at ,alaba%ka1 ne> ,ekat]9burg1 9 ! ,gov]nm5t ( ,p]m1 & at ,miask 9 ! ,ilm5 ,m\nta9s1 9 ! ,gov]nm5t ( ,or5burg4 ,topazes ( ! r>e r$di% hue h be5 pick$ out f ! gold wa%+s ( ! ,san>ka ,riv]1 ,troitsk1 also 9 ! ,gov]nm5t ( ,or5burg4 ,spl5did pale-br[n /ones h issu$ f ! ,urulga ,riv]1 ne> ,n]ts*9sk1 & good cry/als h come f ! ,adun-,ts*ilon ,m\nta9s4 ,kam*atka has produc$ yell[1 blue1 & gre5 /ones4 ,9 ! ,briti% ,isles1 beautiful sky-blue1 wat]worn cry/als h be5 f\nd at ,cairngorm1 ,banff%ire1 9 ,scotl&1 & col\rless /ones 9 ! ,m\rne ,m\nta9s1 ,irel&1 & at ,/4 ,mi*ael's ,m\nt1 ,cornwall4 ,mo/ ( ! topazes us$ 9 jewell]y ( ! pres5t day come f ei!r ,brazil or ,ceylon4 ,ouro ,preto1 ,villa ,rica1 & ,m9as ,novas1 9 ! ,/ate ( ,m9as ,g]aes1 are ! pr9cipal localities 9 ,brazil4 ,num]\s /ones1 (t5 wat]worn1 brilliant & col\rless or t9t$ lovely %ades ( blue & w9e-yell[1 occur !re2 r$di% /ones also h be5 f\nd at ,ouro ,preto4 ,ceylon furni%es a pr(usion ( yell[1 light-gre51 & col\rless1 wat]worn pebbles4 ,! col\rless /ones f\nd !re are incorrectly t]m$ by ! natives #8wat]-sapphire1' & ! light-gre5 /ones are sold ) b]yl z aquam>9es2 ! /ones locally kn[n z #8k+ topaz' are really yell[ corundum 7cf4 p4 #aha74 ,col\rless cry/als1 sometimes ) a fa9t t+e ( col\r1 h be5 discov]$ 9 _m p>ts ( ! _w1 su* z ,ramona1 ,san ,diego ,c\nty1 ,cali=nia1 & ,pike's ,peak1 ,colorado1 9 ! ,unit$ ,/ates1 ,san ,luis ,potosi 9 ,mexico1 & ,omi & ,otami-yama 9 ,japan4 ,,*apt] ,,xxii ,,sp9el 7,balas-,ruby1 ,rubicelle7 ,sp9el lab\rs "u ! s]i\s disadvantage ( be+ ov]%ad[$ at almo/ all po9ts by its opul5t & m fam\s c\s9s1 sapphire & ruby1 & is n s well kn[n z x des]ves to be4 ,! only v>iety :i* is valu$ z a gem is ! rose-t9t$ /one call$ balas-ruby 7,plate ,,xxvii1 ,fig4 #c71 :i* is v simil> to ! true ruby 9 appe>ance2 !y are probably (t5 confus$1 especially s9ce !y are f\nd 9 intimate association 9 nature4 ,sp9els ( o!r col\rs are n v attractive to ! eye1 & are n likely to be 9 mu* dem&4 ,blue sp9el 7,plate ,,xxvii1 ,fig4 #d7 is f> f common1 b ! %ade is incl9$ to /eely-blue1 & is mu* inf]ior to ! sup]b t9t ( ! true sapphire4 ,sp9el is v h>d & em95tly suitable = a r+-/one1 b is seldom l>ge & transp>5t en\gh = l>g] articles ( jewell]y4 ,sp9el is an alum9ate ( magnesium correspond+ to ! =mula ,mg,al#b,o#d1 & !re=e is closely ak9 to corundum1 alum9a1 & *rysob]yl1 alum9ate ( b]yllium4 ,! composition may1 h[ev]1 v>y consid]ably ow+ to ! isomorph\s replacem5t ( "o elem5t by ano!r2 9 p>ticul>1 f]r\s oxide or manganese oxide (t5 takes ! place ( "s magnesia1 & f]ric oxide or *romic oxide is f\nd in/ead ( "p ( ! alum9a4 ,:5 pure1 sp9el is devoid ( col\r1 b su* /ones are exce$+ly r>e4 ,no d\bt *romic oxide is responsible = ! rose-r$ hue ( balas-ruby1 & also1 :5 temp]$ by f]ric oxide1 = ! orange t9t ( rubicelle1 & manganese is probably ! cause ( ! peculi> violet col\r ( alm&9e-sp9el4 ,x is sc>cely possible to def9e all ! %ades betwe5 blue & r$ t may be assum$ by sp9el4 ,/ones :i* are ri* 9 iron are kn[n z pleona/e or ceylonite2 !y are q opaque1 b are sometimes us$ = ornam5tal we>4 ,! "n ( ! species comes f a dim9utive =m ( 1 a sp>k1 & ref]s to ! fi]y r$ col\r ( ! mo/ valu$ k9d ( sp9el4 ,x may be not$ t ! ,lat9 equival5t ( ! ^w1 c>bunculus1 has be5 appli$ to ! crimson g>net :5 cut en cabo*on4 ,balas is d]iv$ f ,balascia1 ! old "n = ,badak%an1 ! di/rict f :i* ! f9e/ /ones 7 br\ght 9 m$ival times4 ,illu/ration3 ,,figs4 #gc1 #gd4--,sp9el ,cry/als4 ,sp9el1 l diamond1 belongs to ! cubic sy/em ( cry/all9e symmetry1 & occurs 9 beautiful octah$ra1 or 9 flat triangul>-%ap$ plates 7,figs4 #gc1 #gd7 ! girdles ( :i* are cleft at ea* corn]1 ^! plates be+ really tw9n$ octah$ra4 ,! refraction is1 ( c\rse1 s+le1 & !re is !re=e no d\ble refraction or di*roism2 ?is te/ furni%es ! simple/ way ( discrim9at+ betwe5 ! balas & ! true ruby4 ,ow+ to isomorph\s replacem5t ! value ( ! refractive index may lie any:]e betwe5 #agaf & #agcf4 ,! l[] values1 ab\t #agbj1 correspond to ! mo/ transp>5t r$ & blue /ones2 ! deep violet /ones h values above #agcj4 ,sp9el possesses little col\r-disp]sion1 or #8fire4' ,9 ! same way ! values ( ! specific gravity1 ev5 ( ! transp>5t /ones1 v>y betwe5 #ce & #cg1 b ! opaque ceylonite has values z high z #da4 ,sp9el is slightly s(t] ?an sapphire & ruby1 & has ! symbol #h on ,mohs's scale1 & x is sc>cely inf]ior 9 lu/re to ^! /ones4 ,sp9el is easily sep>at$ f g>net ( simil> col\r by its l[] refractivity4 ,sp9els run f #ajs4 to #e a c>at1 dep5d+ on _! col\r & quality1 & exceptional /ones comm& a high] rate4 ,sp9el always occurs 9 close association ) corundum4 ,! balas & ! true ruby are mix$ toge!r 9 ! lime/ones ( ,burma & ,siam4 ,curi\sly en\gh1 ! sp9el despite its l[] h>dness is f\nd 9 ! riv] gravels 9 p]fect cry/als1 :]eas ! rubies are g5]ally wat]worn4 ,f9e violet & blue sp9els occur 9 ! prolific gem-gravels ( ,ceylon4 ,a l>ge wat]worn octah$ron & a r\gh mass1 bo? ( a f9e r$ col\r1 are exhibit$ 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory71 & a beautiful facet$ blue /one is %[n close by4 ,! enorm\s r$ /one1 oval 9 %ape1 :i* is set 9 front ( ! ,engli% cr[n1 is n a ruby1 z x 0 =m]ly believ$ to be1 b a sp9el4 ,x 0 giv5 to ! gallant ,black ,pr9ce by ,p$ro ! ,cruel aft] ! battle ( ,naj]a 9 #acfg1 & 0 subsequ5tly worn by ,h5ry ,v ^u 8 helmet at ! battle ( ,ag9c\rt4 ,z usual ) ,indian-fa%ion$ /ones x is pi]c$ ?r\gh ! middle1 b ! hole is n[ hidd5 by a small /one ( simil> col\r4 ,! ,briti% ,regalia also conta9s ! fam\s /one call$ ! ,timur ,ruby or ,khiraj-i-,alam 7,tribute ( ! ,_w71 :i* weighs j ov] #ceb c>ats1 & is ! l>ge/ sp9el-ruby kn[n4 ,x is uncut1 b poli%$4 ,its hi/ory goes back to #acih1 :5 x 0 captur$ by ! ,amir ,timur at ,delhi4 ,on ! wane ( ! ,t>t> empire ! /one became ! prop]ty ( ! ,%ahs ( ,p]sia1 until x 0 giv5 by ,abbas ,i to 8 fri5d & ally1 ! ,mogul ,emp]or1 ,jehangir4 ,x rema9$ at ,delhi until1 on ! sack ( t city by ,nadir ,%ah 9 #agci1 x1 toge!r ) imm5se booty1 includ+ ! ,koh-i-nor1 fell into ! h&s ( ! conqu]or4 ,l ! great diamond1 x ev5tually came into ! possession ( ,runjit ,s+h at ,lahore1 & on ! annexation ( ! ,punjab 9 #ahej pass$ to ! ,ea/ ,india ,company4 ,x 0 %[n at ! ,great ,exhibition ( #ahea1 & aft]w>ds pres5t$ to ,que5 ,victoria4 ,m5tion has be5 made above 7p4 #aba7 ( ! blue sp9el :i* is manufactur$ 9 imitation ( ! true sapphire4 ,! artificial /one is q diff]5t 9 t9t f ! blue sp9el f\nd 9 nature4 ,,*apt] ,,xxiii ,,g>net ,! important gr\p ( m9]als :i* are kn[n "u ! g5]al "n ( g>net provides an apt illu/ration ( ! fact t r>ity is an ess5tial condition if a /one is to be acc\nt$ preci\s4 ,ow+ to ! l>ge quantity ( ,bohemian g>nets1 ( a n v attractive %ade ( yell[i% r$1 t h be5 lit]ally p\r$ ^u ! m>ket dur+ ! pa/ half-c5tury ! species has become associat$ ) *eap & (t5 ineffective jewell]y1 & has acquir$ a /igma :i* completely prev5ts its atta9+ any popul>ity ) ^? pr(ess+ a nice ta/e 9 gem-/ones4 ,x mu/ n1 h[ev]1 be suppos$ t g>net has entirely disappe>$ f high-class jewell]y al?\gh ! "n may n readily be f\nd 9 a jewell]'s catalogue4 ,^? ^: bus9ess x is to sell gem-/ones are fully alive to ! importance ( a "n1 &1 z has already be5 rem>k$ 7p4 #aji71 !y h be5 fa9 to meet ! prejudices ( _! cu/om]s by (f]+ g>nets "u su* mislead+ guises z #8,cape-ruby1' #8,uralian em]ald1' or #8oliv9e4' ,g>nets may1 moreov]1 figure "u ano!r "n q un9t5tionally4 ,probably _m a f9e /one masqu]ades z a true ruby2 ! impossibility ( di/+ui%+ ^! two species 9 c]ta9 cases by eye alone is p]haps n widely recogniz$4 ,an in/ructive in/ance came "u ! writ]'s notice a few ye>s ago4 ,a lady "o day _h ! mis=tune to fracture "o ( ! /ones 9 a ruby r+ t _h be5 9 ! possession ( h] family = upw>ds ( a c5tury1 & 0 orig9ally pur*as$ ( a lead+ firm ( jewell]s 9 ,london4 ,%e took ! r+ to h] jewell]1 & ask$ him to h ! /one replac$ by ano!r ruby4 ,a day or two lat] he s5t ^w t x 0 sc>cely wor? :ile to put a ruby 9 because ! /ones 9 ! r+ 7 pa/e4 ,naturally di/ress$ at su* an op9ion ( a r+ :i* _h always be5 held 9 great e/eem by h] family1 ! lady consult$ a fri5d1 :o sugge/$ %[+ x to ! writ]4 ,a glance 0 suffici5t to prove t if ! r+ _h be5 9 use s long ! /ones c\ld n possibly be pa/e on acc\nt ( ! excell5t /ate ( _! poli%1 b a te/ ) ! refractomet] %[$ t ! /ones 7 really alm&9e-g>nets1 :i* s (t5 closely resemble ! true ruby 9 appe>ance4 ,beautiful z ! /ones 71 ! r+ 0 probably n wor? "o-t5? :at ! value w\ld h be5 _h ! /ones be5 rubies4 ,to ! /ud5t ( m9]alogy g>net is = _m reasons ( peculi> int]e/4 ,x af=ds an excell5t illu/ration ( ! facility :i* c]ta9 elem5ts possess = replac+ "o ano!r )\t any great di/urbance ( ! cry/all9e =m4 ,despite _! app>5t complexity 9 composition all g>nets con=m to ! same type ( =mula3 lime1 magnesia1 & f]r\s & manganese oxides1 & aga9 alum9a & f]ric & *romic oxides may replace ea* o!r 9 any proportion1 iron be+ pres5t 9 two /ates ( oxidation1 & x w\ld be r>e to f9d a /one :i* agrees 9 composition exactly ) any ( ! diff]5t v>ieties ( g>net giv5 bel[4 ,illu/ration3 ,,figs4 #ge1 #gf4--;,g>net ,cry/als4 ,g>net belongs to ! cubic sy/em ( cry/all9e symmetry4 ,its cry/als are commonly ( two k9ds1 bo? ( :i* are v *>act]i/ic1 ! regul> dodecah$ron1 i4e4 twelve-fac$ figure 7,fig4 #ge71 & ! tetrakis-octah$ron or ?ree-fac$ octah$ron 7,fig4 #gf72 ! latt] cry/als are1 especially :5 wea!r- or wat]-worn1 almo/ sph]ical 9 %ape4 ,clos] & m ref9$ obs]vations h %[n t g>net is seldom homog5e\s1 be+ usually compos$ ( sev]al di/9ct individuals ( a l[] ord] ( symmetry4 ,al?\gh s+ly refractive z f> z c be det]m9$ ) ! refractomet] or by deviation ?r\gh a prism1 yet :5 exam9$ "u ! pol>iz+ microscope1 g>nets display inv>iably a small am\nt ( local d\ble refraction4 ,! transition f light to d>kness is1 h[ev]1 n %>p z 9 normal cases1 b is prolong$ into a k9d ( twilight4 ,9 h>dness1 g>net is on ! :ole ab\t ! same z qu>tz1 b v>ies slightly2 hessonite & &radite are a little s(t]1 pyrope1 spess>tite1 & alm&9e are a little h>d]1 :ile uv>ovite is almo/ ! same4 ,all ! v>ieties except uv>ovite are fusible :5 heat$ be=e ! bl[pipe1 & small fragm5ts melt suffici5tly on ! surface 9 ! ord9>y buns5 flame to adh]e to ! plat9um wire hold+ !m4 ,?is te/ is v useful = sep>at+ r\gh r$ g>nets1 pyrope or alm&9e1 f r$ sp9els or zircons ( v simil> appe>ance4 ,f> great] v>iation occurs 9 ! o!r physical *>act]s4 ,! specific gravity may h any value betwe5 #cee & #dbj1 & ! refractive index ranges betwe5 #agdj & #ahij4 ,bo? ! specific gravity & ! refractive index increase on ! :ole ) ! p]c5tage am\nt ( iron4 ,g>net is a prom95t con/itu5t ( _m k9ds ( rocks1 b ! mat]ial mo/ suitable = gem purposes occurs *iefly 9 cry/all9e s*i/s or metamorphic lime/ones4 ,pyrope & demantoid are furni%$ by p]idotites & ! s]p5t9es result+ f !m2 alm&9e & spess>tite come mo/ly f granites4 ,! "n ( ! species is d]iv$ f ! ,lat9 granatus1 se$-l1 & is sugge/$ by ! appe>ance ( ! sph]ical cry/als :5 emb$d$ 9 _! pudd+-l matrix4 ,! v>ieties mo/ adapt$ to jewell]y are ! fi]y-r$ pyrope & ! crimson & columb9e-r$ alm&9e2 ! clos] !y approa* ! ruddy hue ( ruby ! bett] !y are appreciat$4 ,hessonite 0 at "o "t 9 "s dem&1 b x incl9es too mu* to ! yell[i% %ade ( r$ & possesses too little p]fection ( transp>5cy to accord ) ! ta/e ( ! pres5t day4 ,demantoid provides beautiful1 pale & d>k em]ald-gre5 /ones1 ( brilliant lu/re & high disp]sion1 :i* are admirably adapt$ = use 9 p5dants or necklaces2 on acc\nt ( _! comp>ative s(tness x w\ld be unwise to risk !m 9 r+s4 ,9 _m /ones ! col\r takes a yell[i% %ade1 :i* is less 9 dem&4 ,uv>ovite also occurs 9 attractive em]ald-gre5 /ones1 b un=tunately none z yet h be5 f\nd l>ge en\gh = cutt+4 ,a few truly magnific5t spess>tites are kn[n--"o1 a spl5did example1 weigh+ #f c>ats1 be+ 9 ! possession ( ,sir ,ar?ur ,*ur*2 b ! species is f> too seldom transp>5t to come into g5]al use4 ,! price v>ies p] c>at f #bs4 = common g>net to #ajs4 = /ones mo/ ak9 to ruby 9 col\r1 & exceptional demantoids may realize ev5 z mu* z #aj a c>at4 ,! old /yle ( cutt+ 0 almo/ inv>iably r\nd$ or en cabo*on1 b at ! pres5t day ! brilliant-cut front & ! /ep-cut back is mo/ commonly adopt$4 ,! sev]al v>ieties w n[ be consid]$ 9 detail4 7a7 ,,hessonite 7,grossul>1 ,c9namon-,/one1 ,hyac9?1 ,jac9?7 ,?is v>iety1 /rictly a calcium-alum9ium g>net correspond+ to ! =mula ,ca#c;,al#b7,si,o#d7c1 b g5]ally conta9+ "s f]ric oxide & !re=e t5d+ t[>ds &radite1 is call$ by sev]al diff]5t names4 ,9 sci5ce x is usually t]m$ grossul>1 a ^w d]iv$ f grossul>ia1 ! botanical "n = gooseb]ry1 9 allusion to ! col\r & appe>ance ( _m cry/als1 or hessonite1 & less correctly essonite1 words d]iv$ f ! ,greek 9 ref]5ce to ! inf]ior h>dness ( ^! /ones z comp>$ ) zircon ( simil> col\r2 9 jewell]y x is bett] kn[n z c9namon-/one1 if a gold5-yell[ 9 col\r1 or hyac9? or jac9?4 ,! la/ ^w1 :i* is indiscrim9ately us$ = hessonite & yell[ zircon1 b %\ld m prop]ly be appli$ to ! latt]1 is d]iv$ f an old ,indian ^w 7cf4 p4 #bbi72 jewell]s1 h[ev]1 reta9 x = ! g>net4 ,only ! yell[ & orange %ades ( hessonite 7,plate ,,xxix1 ,fig4 #e7 are us$ = jewell]y4 ,nei!r ! br[ni%-gre5 k9d1 to :i* ! t]m grossul> may prop]ly be appli$1 nor ! rose-r$ is transp>5t en\gh to s]ve z a gem-/one4 ,hessonite may mo/ly be recogniz$1 ev5 :5 cut1 by ! curi\sly granul> nature ( its /ructure1 j z if x 7 compos$ ( t9y gra9s imp]fectly fus$ toge!r2 ?is appe>ance1 :i* is v *>act]i/ic1 may readily be p]ceiv$ if ! int]ior ( ! /one be view$ ?r\gh a l5s ( mod]ate p[]4 ,! specific gravity v>ies f #cee to #cff1 & ! refractive index f #agdb to #agdh4 ,! h>dness is on ! :ole slightly bel[ t ( qu>tz4 ,:5 heat$ be=e a bl[pipe x easily fuses to a gre5i% glass4 ,! mo/ suitable mat]ial is f\nd 9 "s pr(usion 9 ! gem-gravels ( ,ceylon1 9 :i* x is mix$ up ) zircon ( an almo/ id5tical appe>ance2 bo? are call$ hyac9?4 ,hessonites f o!r localities1 al?\gh attractive z museum specim5s1 are n l>ge & cle> en\gh = cutt+ purposes4 ,switz]l& at "o "t suppli$ good /ones1 b ! supply has long be5 exhau/$4 7b7 ,,pyrope 7#8,cape-,ruby'7 ,(t5 q ruby-r$ 9 col\r 7,plate ,,xxix1 ,fig4 #f71 ?is v>iety is probably ! mo/ popul> ( ! g>nets4 ,x is /rictly a magnesium-alum9ium g>net correspond+ to ! =mula ,mg#c;,al#b7,si,o#d7c1 b usually conta9s "s f]r\s oxide & ?us approa*es alm&9e4 ,bo? are includ$ among ! preci\s g>nets4 ,its "n is d]iv$ f 1 fire-l1 9 obvi\s allusion to its *>act]i/ic col\r4 ,al?\gh at its be/ pyrope closely resembles ruby1 its appe>ance is (t5 m>r$ by a t+e ( yell[ :i* decid$ly detracts f its value4 ,pyrope g5]ally passes z a v>iety ( ruby1 & "u su* names z #8,cape-ruby1' #8,arizona-ruby1' dep5d+ on ! orig9 ( ! /ones1 comm&s a brisk sale4 ,! specific gravity v>ies upw>ds f #cgj1 dep5d+ ^u ! p]c5tage am\nt ( iron pres5t1 & simil>ly ! refractive index v>ies upw>ds f #agdj2 9 ! high] values pyrope m]ges into alm&9e4 ,its h>dness is slightly great] ?an t ( qu>tz1 & may be express$ on ,mohs's scale by ! symbol #g4 ,an enorm\s quantity ( small r$ /ones1 mo/ly ) a slight t+e ( yell[1 h be5 br\ght to light at ,teplitz1 ,aussig1 & o!r spots 9 ! ,bohemian ,mittelgebirge1 & a consid]able indu/ry 9 cutt+ & m>t+ !m has gr[n up at ,bil94 ,f9e ruby-r$ /ones accompany diamond 9 ! #8blue gr\nd' ( ! m9es at ,kimb]ley & also at ! ,premi] m9e 9 ! ,transvaal4 ,simil> /ones are also f\nd 9 ,arizona & ,colorado 9 ! ,unit$ ,/ates1 & 9 ,au/ralia1 ,rhodesia1 & else:]e4 ,al?\gh commonly q small 9 size1 pyrope has occasionally atta9$ to consid]able size4 ,accord+ to ,de ,boodt ! ,kais] ,rudolph ,,ii _h "o 9 8 possession valu$ at #de1jjj ?al]s 7ab\t #fgej74 ,! ,imp]ial ,treasury at ,vi5na conta9s a /one z l>ge z a h5's egg4 ,ano!r ab\t ! size ( a pigeon's egg is 9 ! fam\s ,gre5 ,vaults at ,dresd51 & ! ,k+ ( ,saxony has "o1 weigh+ #dfh c>ats1 set 9 an ,ord] ( ! ,gold5 ,fleece4 7c7 ,,rhodolite ,?is *>m+ pale-violet v>iety 0 f\nd at ,c[ee ,creek & at ,mason's ,bran*1 ,macon ,c\nty1 ,nor? ,c>ol9a1 ,u4,s4,a41 b 9 too limit$ am\nt to assume ! position 9 jewell]y x might o!rwise h expect$4 ,9 composition x lies betwe5 pyrope & alm&9e1 & may be suppos$ to conta9 a proportion ( two molecules ( ! =m] to "o ( ! latt]4 ,its specific gravity is #chd1 refractive index #agfj1 & h>dness #g4 ,x exhibits 9 ! spectroscope ! absorption-b&s *>act]i/ic ( alm&9e4 7d7 ,,alm&9e 7,c>buncle7 ,?is v>iety is iron-alum9ium g>net correspond+ to ! =mula ,fe#c;,al#b7,si,o#d7c1 b ! composition is v v>iable4 ,9 col\r x is deep crimson & violet or columb9e-r$ 7,plate ,,xxix1 ,fig4 #h71 b ) increas+ p]c5tage am\nt ( f]ric oxide x becomes br[n & black1 & opaque1 & q unsuitable = jewell]y4 ,! "n ( ! v>iety is a corruption ( ,alab&a 9 ,asia ,m9or1 :]e 9 ,pl9y's "t ! be/ r$ /ones 7 cut4 ,alm&9e is sometimes kn[n z ,syriam1 or incorrectly ,syrian g>net1 because at ,syriam1 once ! capital ( ! anci5t k+dom ( ,pegu1 :i* n[ =ms "p ( ,l[] ,burma1 su* /ones 7 cut & sold4 ,crimson /ones1 cut 9 ! famili> en cabo*on =m & kn[n z c>buncles1 7 ext5sively employ$ = enri*+ metalwork1 & a half-c5tury or s ago 7 v popul> = ornam5tal we>1 b _! day has long s9ce gone4 ,su* gl[+ /ones are aptly describ$ by _! "n1 :i* is d]iv$ f ! ,lat9 c>bunculus1 a little sp>k4 ,9 ,pl9y's "t1 h[ev]1 ! t]m 0 us$ indiscrim9ately = all r$ /ones4 ,x has already be5 rem>k$ t ! ^w sp9el has a simil> significance4 ,! specific gravity v>ies f #cij = transp>5t /ones to #dbj = ! d5se/ black /ones1 & ! refractive index may be z high z #ahaj4 ,alm&9e is "o ( ! h>de/ ( ! g>nets1 & is repres5t$ by ! symbol #g on ,mohs's scale4 ,! mo/ int]e/+ & curi\s feature ( alm&9e lies 9 ! rem>kable & *>act]i/ic absorption-spectrum reveal$ :5 ! transmitt$ light is exam9$ ) a spectroscope 7p4 #fa74 ,! ph5om5on is display$ mo/ vividly by ! violet /ones1 & is1 inde$1 ! cause ( _! peculi> col\r4 ,al?\gh a common m9]al1 alm&9e ( a quality fitt$ = jewell]y occurs 9 comp>atively few localities4 ,x is f\nd 9 ,ceylon1 b n s pl5tifully z hessonite4 ,good /ones are m9$ 9 v>i\s p>ts ( ,india1 & are ne>ly all cut at ,delhi or ,jaipur4 ,brazil supplies good mat]ial1 especially 9 ! ,m9as ,novas di/rict ( ,m9as ,g]aes1 :]e x accompanies topaz1 & ,uruguay also furni%es s]viceable /ones4 ,alm&9e is f\nd 9 ,au/ralia1 & 9 _m p>ts ( ! ,unit$ ,/ates4 ,rec5tly small /ones ( good col\r h be5 discov]$ at ,luis5felde 9 ,g]man ,ea/ ,africa4 7e7 ,,spess>tite ,prop]ly a manganese-alum9ium g>net correspond+ to ! =mula ,mn#c;,al#b7,si,o#d7c1 ?is v>iety g5]ally conta9s iron 9 bo? /ates ( oxidation4 ,if only transp>5t & l>ge en\gh its aurora-r$ col\r w\ld r5d] x mo/ acceptable 9 jewell]y4 ,two spl5did /ones h1 inde$1 be5 f\nd 9 ,ceylon 7p4 #baa71 & good /ones r resembl+ hessonites h be5 qu>ri$ at ,amelia ,c\rt ,h\se 9 ,virg9ia1 & o!rs h come f ,nevada2 o!rwise1 spess>tite is unkn[n z a gem-/one4 ,! specific gravity ranges f #dj to #dc1 & ! refractive index is ab\t #aha1 bo? *>act]s be+ high2 ! h>dness is slightly great] ?an t ( qu>tz4 7f7 ,,&radite 7,demantoid1 ,topazolite1 #8,oliv9e'7 ,&radite is /rictly a calcium-iron g>net correspond+ to ! =mula ,ca#c;,fe#b7,si,o#d7c1 b z usual ! composition v>ies consid]ably4 ,x is nam$ aft] d',&rada1 a ,portuguese m9]alogi/1 :o made a /udy ( g>net m ?an a c5tury ago4 ,once contemptu\sly /yl$ common g>net1 &radite sudd5ly sprang into ! rank ( preci\s /ones ^u ! discov]y "s ?irty ye>s ago ( ! brilliant1 gre5 /ones 7,plate ,,xxix1 ,fig4 #g7 9 ! s]p5t9\s rock beside ! ,bobrovka /ream1 a tribut>y ( ! ,ts*uss[aja ,riv]1 9 ! ,siss]sk di/rict on ! we/]n side ( ! ,ural ,m\nta9s4 ,! %ade ( gre5 v>ies f olive ?r\gh pi/a*io to a pale em]ald1 & is probably due to *romic oxide4 ,its brilliant lu/re1 almo/ *all5g+ t ( diamond1 & its enorm\s col\r-disp]sion1 9 :i* respect x actually transc5ds diamond1 raise x to a unique position among col\r$ /ones4 ,un=tunately its comp>ative s(tness limits x to su* articles ( jewell]y z p5dants & necklaces1 :]e x is n likely to be rubb$4 ,:5 fir/ f\nd x 0 suppos$ to be true em]ald1 :i* does actually occur ne> ,ekat]9burg1 & 0 t]m$ #8,uralian em]ald4' ,:5 analysis reveal$ its true nature1 x receiv$ f sci5ce ! slightly inh>moni\s "n ( demantoid 9 complim5t to its adamant9e lu/re4 ,jewell]s1 h[ev]1 pref] to designate x #8oliv9e1' n v happily1 because ! /ones usually cut are n olive-gre5 & ! "n is already 9 ext5sive use 9 sci5ce = a totally di/9ct species 7p4 #bbe72 !y recogniz$ ! hopelessness ( endeav\r+ to f9d a m>ket = !m z g>nets4 ,! yell[ k9d ( &radite kn[n z topazolite w\ld be an excell5t gem-/one if only x 7 f\nd l>ge & transp>5t en\gh4 ,ord9>y &radite is br[n or black1 & opaque2 x has occasionally be5 us$ = m\rn+ jewell]y4 ,! specific gravity v>ies f #ch to #ci1 be+ ab\t #che = demantoid1 :i* has a high refractive index1 v>y+ f #ahhj to #ahij1 & may ) advantage be cut 9 ! brilliant =m4 ,x is ! s(te/ ( ! g>nets1 be+ only #f on ,mohs's scale4 7g7 ,,uv>ovite ,?is v>iety1 :i* is altoge!r unkn[n 9 jewell]y1 is a calcium-iron g>net correspond+ ma9ly to ! =mula ,ca#c;,cr#b7,si,o#d7c1 b ) "s alum9a always pres5t1 & 0 nam$ aft] a ,russian m9i/]4 ,x has an attractive gre5 col\r1 & is1 moreov]1 h>d1 be+ ab\t on ,mohs's scale1 b x has nev] yet come to light ( a size suitable = cutt+4 ,! specific gravity is l[1 v>y+ f #cda to #ceb4 ,unlike ! k9dr$ v>ieties x _c be fus$ by heat+ be=e an ord9>y bl[pipe4 ,,*apt] ,,xxiv ,,t\rmal9e 7,rubellite7 ,t\rmal9e is unsurpass$ ev5 by corundum 9 v>iety ( hue1 & x has dur+ rec5t ye>s rapidly advanc$ 9 public fav\r1 ma9ly ow+ to ! prodigal pr(usion 9 :i* nature has =m$ x 9 t fav\r$ ,/ate1 ,cali=nia1 ! g>d5 ( ! we/4 ,its comp>ative s(tness militates aga9/ its use 9 r+s1 b its gorge\s coloration r5d]s x admirably fitt$ = s]vice 9 any article ( jewell]y1 su* z a broo* or a p5dant1 9 :i* a l>ge c5tral /one is requir$4 ,l all col\r$ /ones x is g5]ally brilliant-cut 9 front & /ep-cut at ! back1 b occasionally x is suffici5tly fibr\s 9 /ructure to display1 :5 cut en cabo*on1 pron\nc$ *atoyancy4 ,! composition ( ?is complex species has long be5 a vex$ "q among m9]alogi/s1 b consid]able light 0 rec5tly ?r[n on ! subject by ,s*all]1 :o %[$ t all v>ieties ( t\rmal9e may be ref]r$ to a =mula ( ! type #ab,si,o#b4c;,b#b,o#c47i-x77,al1,fe7#b,o #c4cx7,fe1,mn1,ca1 ,mg1,k#b1,na#b1,li#b1;,h#b7,o4#c;,h#b,o4 ,! ratios ( boric oxide1 silica1 & wat] are ne>ly con/ant 9 all analyses1 b great v>iation is possible 9 ! proportions ( ! o!r con/itu5ts4 ,hav+ reg>d to ?is complexity1 x is n surpris+ to f9d t ! range 9 col\r is s great4 ,col\rless /ones1 to :i* ! "n a*roite is sometimes giv51 7 at "o "t exce$+ly r>e1 b !y are n[ f\nd 9 great] numb] 9 ,cali=nia4 ,/ones :i* are mo/ suit$ to jewell]y purposes are comp>atively free f iron1 & app>5tly owe _! wond]ful t9ts to ! alkal9e e>?s2 li?ia1 = in/ance1 is responsible = ! beautiful t9t ( ! highly priz$ rubellite1 & magnesia1 no d\bt1 = ! col\r ( ! br[n /ones ( v>i\s t9ts4 ,t\rmal9e ri* 9 iron is black & almo/ opaque4 ,x is a /rik+ peculi>ity ( ! species t ! cry/als are r>ely uni=m 9 col\r ?r\gh\t1 ! b\nd>ies betwe5 ! diff]5tly col\r$ portions be+ %>p & abrupt1 & ! t9ts rem>kably 9 contra/4 ,sometimes ! sections are sep>at$ by planes at "r angles to ! l5g? ( ! cry/al1 & sometimes !y are zonal1 b\nd$ by cyl9drical surfaces runn+ p>allel to ! same l5g?4 ,9 ! latt] case a section p]p5dicul> to ! l5g? %[s zones ( at lea/ ?ree contra/+ t9ts4 ,9 ! ,brazilian /ones ! core is g5]ally r$1 b\nd$ by :ite1 ) gre5 on ! ext]ior1 :ile ! rev]se is ! case 9 ! ,cali=nian /ones1 ! core be+ gre5 or yell[1 b\nd$ by :ite1 ) r$ on ! ext]ior4 ,t\rmal9e may1 inde$1 be f\nd ( almo/ e imag9able t9t1 except1 p]haps1 ! em]ald gre5 & ! royal sapphire-blue4 ,! pr9cipal v>ieties are rose-r$ & p9k 7rubellite7 7,plate ,,xxvii1 ,fig4 #a71 gre5 7,brazilian em]ald71 indigo-blue 7indicolite71 blue 7,brazilian sapphire71 yell[i% gre5 7,brazilian p]idot7 7,plate ,,xxvii1 ,fig4 #b71 honey-yell[ 7,ceylonese p]idot71 violet-r$ 7sib]ite71 & br[n 7,plate ,,xxvii1 ,fig4 #h74 ,! black1 opaque /ones are t]m$ s*orl4 ,! "n ( ! species is d]iv$ f ! ,ceylonese ^w1 turamali1 & 0 fir/ employ$ :5 a p>cel ( gem-/ones 0 br\ght to ,am/]dam f ,ceylon 9 #agjc2 9 ,ceylon1 h[ev]1 ! t]m is appli$ by native jewell]s to ! yell[ zircon commonly f\nd 9 ! isl&4 ,s*orl1 ! d]ivation ( :i* is unkn[n1 is ! anci5t "n = ! species1 & is /ill us$ 9 t s5se by m9]s1 b x has be5 re/rict$ by sci5ce to ! black v>iety4 ,! #8,brazilian em]ald' 0 introduc$ into ,europe 9 ! sev5te5? c5tury & 0 n fav\rably receiv$1 possibly because ! /ones 7 too d>k 9 col\r & 7 n prop]ly cut2 t !y %\ld h be5 confus$ ) ! true em]ald is eloqu5t te/imony to ! extreme ignorance ( ! *>act]s ( gem-/ones preval5t 9 ^? d>k ages4 ,a*roite comes f ! ,greek1 1 )\t col\r4 ,illu/ration3 ,,fig4 #gg4--,t\rmal9e ,cry/al4 ,to ! cry/allograph] t\rmal9e is "o ( ! mo/ int]e/+ ( m9]als4 ,if ! cry/als1 :i* are usually prismatic 9 =m1 are d\bly t]m9at$1 ! developm5t is s obvi\sly diff]5t at ! two ends 7,fig4 #gg7 z to indicate t directional "* 9 ! molecul> arrangem5t1 t]m$ ! pol>ity1 :i* is borne out by o!r physical prop]ties4 ,t\rmal9e is rem>kably di*roic1 ,a br[n /one1 except 9 v ?9 sections1 is practically opaque to ! ord9>y ray1 & consequ5tly a section cut p>allel to ! cry/allographic axis1 i4e4 to ! l5g? ( a cry/al prismatically develop$1 transmits only ! extraord9>y ray4 ,su* sections 7 9 use = yield+ plane-pol>iz$ light be=e ,nicol devis$ ! calcite prism kn[n by 8 "n 7cf4 p4 #dd74 ,x is evid5t t t\rmal9e1 unless v light 9 t9t1 mu/ be cut ) ! table facet p>allel to t axis1 because o!rwise ! /one w appe> d>k & lifeless4 ,! values ( ! extraord9>y & ord9>y refractive indices range betwe5 #afad & #afch1 & #afcc & #affi respectively2 ! d\ble refraction1 !re=e1 is fairly l>ge1 am\nt+ to #jjbe1 &1 s9ce ! ord9>y exce$s ! extraord9>y ray1 its "* is negative4 ,! specific gravity v>ies f #cj to #cb4 ,! l[] values 9 bo? *>act]s correspond to ! light] col\r$ /ones us$ 9 jewell]y2 ! black /ones1 z might be expect$ f _! relative ri*ness 9 iron1 are ! d5se/4 ,! h>dness is only ab\t ! same z t ( qu>tz1 or p]haps a little great]1 v>y+ f #g to #g4 ,x w be notic$ t ! range ( refractivity ov]laps t ( topaz 7q4v47 b ! latt] has a mu* small] d\ble refraction1 & may ?us be di/+ui%$ 7p4 #bi74 ,unm\nt$ /ones are /ill m easily di/+ui%$1 because t\rmal9e floats 9 me?yl5e iodide1 :ile topaz s9ks4 ,! pyro-electric ph5om5on 7cf4 p4 #hb7 = :i* t\rmal9e is rem>kable1 al?\gh ( little value z a te/ 9 ! case ( a cut /one1 is ( great sci5tific int]e/1 because x is /rong evid5ce ( ! peculi> cry/all9e symmetry p]ta9+ to its molecul> arrangem5t4 ,t\rmal9es range 9 price f #es4 to #bjs4 a c>at accord+ to _! col\r & quality1 b exceptional /ones may comm& a high] rate4 ,t\rmal9e is usually f\nd 9 ! pegmatite dykes ( granites1 b x also occurs 9 s*i/s & 9 cry/all9e lime/ones4 ,rubellite is g5]ally associat$ ) ! li?ia mica1 lepidolite2 ! gr\ps ( delicate p9k rubellite bespangl+ a backgr\nd ( greyi% :ite lepidolite are among ! mo/ beautiful ( museum specim5s4 ,magnific5t cry/als ( p9k1 blue1 & gre5 t\rmal9e h be5 f\nd 9 ! neighb\rhood ( ,ekat]9burg1 pr9cipally at ,murs9ka1 9 ! ,urals1 ,russia1 & f9e rubellite has come f ! ,urulga ,riv]1 & o!r spots ne> ,n]ts*9sk1 ,transbaikal1 ,asiatic ,russia4 ,elba produces p9k1 yell[i%1 & gre5 /ones1 frequ5tly p>ticol\r$2 sometimes ! cry/als are black5$ at ! top1 & are !n kn[n locally z #8nigg]-heads4' ,ceylon supplies small yell[ /ones--! orig9al t\rmal9e--:i* are confus$ ) ! zircon ( a simil> col\r1 & rubellite accompanies ! ruby at ,ava1 ,burma4 ,beautiful cry/als1 gre5 & r$1 (t5 div]sely col\r$1 come f v>i\s p>ts1 su* z ,m9as ,novas & ,arassuahy1 ( ! ,/ate ( ,m9as ,g]aes1 ,brazil4 ,suitable gem mat]ial has be5 f\nd 9 num]\s p>ts ( ! ,unit$ ,/ates4 ,p>is & ,hebron 9 ,ma9e h produc$ gorge\s p9k & gre5 cry/als1 & ,auburn 9 ! same /ate has suppli$ deep-blue1 gre51 & lilac /ones4 ,f9e cry/als1 mo/ly gre51 b also p9k & p>ticol\r$1 occur 9 an albite qu>ry ne> ! ,conn ,riv] at ,haddam ,neck1 ,connecticut4 ,all =m] localities h1 h[ev]1 be5 surpass$ by ! extraord9>y abundance ( sup]b gre51 & especially p9k1 cry/als at ,pala & ,mesa ,gr&e 9 ,san ,diego ,c\nty1 ,cali=nia4 ,z else:]e1 _m-hu$ /ones are common4 ,! latt] locality supplies ! m p]fectly transp>5t cry/als4 ,kunz /ates t two rem>kable rubellite cry/als 7 f\nd !re1 "o be+ #de mm4 9 l5g? & #db mm4 9 diamet]1 & ! o!r #ef mm4 9 l5g? & #bd mm4 9 diamet]4 ,madagasc>1 :i* has prov$ ( rec5t ye>s to be ri* 9 gem-/ones1 supplies gre51 yell[1 & r$ /ones1 bo? uni=mly t9t$ & p>ticol\r$1 :i* 9 beauty1 ?\gh p]haps n 9 size1 be> comp>ison ) any f\nd else:]e4 ,,*apt] ,,xxv ,,p]idot ,! beautiful bottle-gre5 /one1 :i* f its delicate t9t has e>n$ f appreciative admir]s ! poetical sobriquet ( ! ev5+ em]ald1 & :i* has dur+ rec5t ye>s crept into popul> fav\r & n[ graces mu* ( ! m arti/ic jewell]y1 is nam$ z a gem-/one p]idot--a ^w long 9 use among ,fr5* jewell]s1 ! orig9 & mean+ ( :i* has be5 =gott5--b is kn[n to sci5ce ei!r z oliv9e1 on acc\nt ( ! olive-gre5 col\r sometimes *>act]iz+ x1 or z *rysolite4 ,x is ( int]e/ to note t ! la/ ^w1 d]iv$ f 1 gold51 & 1 /one1 0 9 use at ! "t ( ,pl9y1 b 0 employ$ = topaz & o!r yell[ /ones1 :ile 8 topaz1 curi\sly en\gh1 designat$ ! mod]n p]idot 7cf4 p4 #aii71 an inv]sion t has occurr$ 9 o!r words4 ,! true oliv9e mu/ n be confus$ ) ! jewell]s' #8oliv9e1' :i* is a gre5 g>net f ! ,ural ,m\nta9s 7p4 #bag74 ,p]idot is comp>atively s(t1 ! h>dness v>y+ f #f to #g on ,mohs's scale1 & is suitable only = articles :i* are n likely to be scrat*$2 ! poli% ( a p]idot worn 9 a r+ w\ld soon det]iorate4 ,! *oice/ /ones are 9 col\r a lovely bottle-gre5 7,plate ,,xxix1 ,fig4 #b7 ( v>i\s dep?s2 ! olive-gre5 /ones 7,plate ,,xxix1 ,fig4 #c7 _c comp>e ) _! si/]s 9 attractiv5ess4 ,! /ep =m ( cutt+ is consid]$ ! be/ = p]idot1 b x is sometimes cut r\nd or oval 9 %ape1 ) brilliant-cut fronts4 ,p]idot is a silicate ( magnesium & iron1 correspond+ to ! =mula 7,mg1,fe7#b,si,o#d1 f]r\s iron1 !re=e1 replac+ magnesia4 ,to ! f]r\s iron x is indebt$ = its col\r1 ! pure magnesium silicate be+ almo/ col\rless1 & ! olive t9t arises f ! oxidation ( ! iron4 ,! latitude 9 ! composition result+ f ?is replacem5t is ev9c$ 9 ! consid]able range t has be5 obs]v$ 9 ! physical *>act]s1 b ! cry/all9e symmetry p]si/s unalt]$2 ! l[] values correspond to ! /ones t are usually met ) z gems4 ,p]idot belongs to ! or?orhombic sy/em ( cry/all9e symmetry1 & ! cry/als1 :i* display a l>ge numb] ( faces1 are prismatic 9 =m & g5]ally some:at flatt5$4 ,! /ones1 h[ev]1 t come into ! m>ket = cutt+ z gems are r>ely unbrok54 ,! di*roism is r fa9t1 "o ( ! tw9 col\rs be+ slightly m yell[i% ?an ! o!r1 b x is m pron\nc$ 9 ! olive-t9t$ /ones4 ,! values ( ! lea/ & greate/ ( ! pr9cipal indices ( refraction v>y greatly1 f #afej & #afhc to #affh & #agja1 b ! d\ble refraction1 am\nt+ to #jjcc1 rema9s unaffect$4 ,p]idot1 ?\gh surpass$ by sph5e 9 ext5t ( d\ble refraction1 easily excels all ! ord9>y gem-/ones 9 ?is respect1 & ?is "* is readily recognizable 9 a cut /one by ! app>5t d\bl+ ( ! opposite edges :5 view$ ?r\gh ! table facet 7cf4 p4 #da74 ,an equally l>ge v>iation occurs 9 ! specific gravity1 namely1 f #cc to #ce4 ,illu/ration3 ,,plate ,,xxvii #a4 ,,rubellite #b4 ,,t\rmal9e #c4 ,,balas-,,ruby #d4 ,,blue ,,sp9el #e4 ,,qu>tz #f4 ,,:ite ,,opal #g4 ,,ame?y/ #h4 ,,t\rmal9e #i4 ,,black ,,opal #aj4 ,,fire ,,opal #aa4 ,,alex&rite 7,by daylight7 #ab4 ,,*rysob]yl #ac4 ,,alex&rite 7,by artificial light7 ,,gem-,,/ones ,p]idots ( deep bottle-gre5 hue comm& mod]ate prices at ! pres5t day1 ab\t #cjs4 a c>at be+ ask$ = l>ge /ones2 ! pal] t9t$ /ones run d[n to a few %ill+s a c>at4 ,! rate p] c>at may be v mu* l>g] = /ones ( exceptional size & quality4 ,oliv9e1 to use ! ord9>y m9]alogical t]m1 is a common & important con/itu5t ( c]ta9 k9ds ( igne\s rocks1 & x is also f\nd 9 ^? /range bodies1 meteorites1 :i* come to u f out] cosmical space4 ,except 9 basaltic lavas1 x occurs 9 gra9s & r>ely 9 well-%ap$ cry/als4 ,/ones t are l>ge & transp>5t en\gh = cutt+ purposes come almo/ entirely f ! isl& ,zebirget or ,/4 ,john situat$ on ! we/ coa/ ( ! ,r$ ,sea1 opposite to ! port ( ,b]5ice4 ,?is isl& belongs to ! ,kh$ive ( ,egypt1 & is at pres5t leas$ to a ,fr5* syndicate4 ,x is believ$ to be ! same z ! my/]i\s isl& :i* produc$ ! #8topaz' ( ,pl9y's "t4 ,magnific5t /ones h be5 discov]$ "h1 ri* gre5 9 col\r1 & #bj to #cj1 & occasionally z mu* z #hj1 c>ats 9 weight :5 cut2 a r\gh mass atta9$ to ! l>ge weight ( #aij c>ats4 ,pretty1 light-gre5 /ones are suppli$ by ,que5sl&1 & p]idots ( a less pleas+ d>k-yell[i% %ade ( gre51 & )\t any sign ( cry/al =m1 h dur+ rec5t ye>s come f ,nor? ,am]ica4 ,/ones r simil> to ^? f ,que5sl& h latt]ly be5 f\nd 9 ! ,b]n>d9o ,valley 9 ,upp] ,burma1 n f> f ! ruby m9es4 ,,*apt] ,,xxvi ,,zircon 7,j>goon1 ,hyac9?1 ,jac9?7 ,zircon1 :i*1 if kn[n at all 9 jewell]y1 is call$ by its v>iety names1 j>goon & hyac9? or jac9?1 is a species t des]ves great] recognition ?an x receives4 ,! col\rless /ones rival ev5 diamond 9 spl5d\r ( brilliance & display ( #8fire'2 ! leaf-gre5 /ones 7,plate ,,xxix1 ,fig4 #ac7 possess a re/ful beauty t comm5ds itself2 ! deep-r$ /ones 7,plate ,,xxix1 ,fig4 #ad71 if some:at sombre1 h a c]ta9 gr&eur2 & no o!r species produces su* magnific5t /ones ( gold5-yell[ hue 7,plate ,,xxix1 ,fig4 #ab74 ,zircon is well kn[n 9 ,ceylon1 :i* supplies ! _w ) ! f9e/ specim5s1 & is highly appreciat$ by ! inhabitants ( t sunny isle1 b x sc>cely f9ds a place 9 jewell]y else:]e4 ,! col\rless /ones are cut z brilliants1 b brilliant-cut fronts ) /ep-cut backs is ! usual /yle adopt$ = ! col\r$ /ones4 ,zircon is a silicate ( zirconium correspond+ to ! =mula ,zr,si,o#d1 b uranium & ! r>e e>?s are g5]ally pres5t 9 small quantities4 ,! aurora-r$ v>iety is kn[n z hyac9? or jac9?1 & ! t]m j>goon is appli$ to ! o!r transp>5t v>ieties1 & especially to ! yell[ /ones4 ,! mo/ attractive col\rs %[n by zircon are leaf-gre51 gold5-yell[1 & deep r$4 ,o!r common col\rs are br[n1 gre5i%1 & sky-blue4 ,col\rless /ones are n f\nd 9 nature1 b result f ! application ( heat to ! yell[ & br[n /ones4 ,! "n ( ! species is anci5t1 & comes f ! ,arabic z>qn1 v]milion1 or ! ,p]sian z>qn1 gold-col\r$4 ,f ! same s\rce 9 all probability is d]iv$ ! ^w j>goon ?r\gh ! ,fr5* j>gon & ! ,italian giacone4 ,hyac9? 7cf4 p4 #baa7 is translit]at$ f ! ,greek 1 itself adapt$ f an old ,indian ^w2 x is 9 no way connect$ ) ! fl[] ( ! same "n4 ,! la/ ^w has se5 "s *anges ( mean+4 ,9 ,pl9y's "t yell[ zircons 7 indiscrim9ately classifi$ ) o!r yell[ /ones z *rysolite4 ,8 hyac9? 0 us$ = ! sapphire ( ! pres5t day1 b 0 subsequ5tly appli$ to any transp>5t corundum4 ,^u ! introduction ( ! t]ms1 sapphire & ruby1 = ! blue & ! r$ corundum hyac9? became re/rict$ to ! o!r v>ieties1 ( :i* ! yell[ 0 ! commone/4 ,9 ! d>kness ( ! ,middle ,ages x 0 loosely employ$ = all yell[ /ones emanat+ f ,india1 & 0 f9ally1 ) increas+ disc]nm5t 9 ! *>act]s ( gem-/ones1 assign$ to ! yell[ zircon1 s9ce x 0 ! commone/ yell[ /one f ,india4 ,illu/ration3 ,,fig4 #gh4--,zircon ,cry/al4 ,consid]$ f ! sci5tific po9t ( view1 zircon is by f> ! mo/ int]e/+ & ! mo/ rem>kable ( ! gem-/ones4 ,! problem pres5t$ by its *>act]s & con/itution is "o t /ill awaits a satisfactory solution4 ,c]ta9 zircons1 :i* are f\nd z roll$ pebbles 9 ,ceylon & nev] %[ any trace ( cry/all9e faces1 h v ne>ly s+le refraction1 & ! values ( ! refractive index v>y f #agij to #ahdj1 & ! specific gravity is ab\t #djj to #dad1 & ! h>dness is slightly great] ?an t ( qu>tz1 be+ ab\t #g4 ,on ! o!r h&1 su* /ones z ! r$ zircons f ,expailly h rem>kably diff]5t prop]ties4 ,!y %[ cry/all9e faces ) tetragonal symmetry1 ! faces pres5t be+ f\r prismatic faces mutually int]sect+ at "r angles & f\r incl9$ faces at ea* end 7,fig4 #gh74 ,!y h l>ge d\ble refraction1 v>y+ f #jjdd to #jjfb1 :i* is readily disc]n$ 9 a cut /one 7cf4 p4 #da71 & ! refractive indices are high1 ! ord9>y index v>y+ f #aibc to #aica & ! extraord9>y f #aifg to #aiic4 ,s9ce ! ord9>y is less ?an ! extraord9>y index ! sign ( ! d\ble refraction is positive4 ,! specific gravity likewise is mu* high]1 v>y+ f #dfg to #dga4 ,! second type1 !re=e1 s9ks 9 molt5 silv]-?allium nitrate1 :]eas ! fir/ type floats4 ,! second type is also slightly h>d]1 be+ ab\t #g on ,mohs's scale4 ,by heat+ ei!r ( ^! types ! physical *>act]s are n mu* alt]$1 except t ! col\r is weak5$ or entirely driv5 (f & "s *ange takes place 9 ! d\ble refraction4 ,b betwe5 ^! two types may be f\nd zircons ^u :i* ! effect ( heat+ is /rik+4 ,!y seem to contract 9 size s t ! specific gravity increases z mu* z ?ree units 9 ! fir/ place ( decimals1 & a correspond+ increase takes place 9 ! refractive indices1 & 9 ! am\nt ( d\ble refraction4 ,! cause ( ^! *anges rema9s a matt] ( speculation4 ,evid5tly a ?ird type ( zircon exi/s :i* is capable ( mo/ intimate association ) ei!r ( ! o!r types1 & :i* is v susceptible to ! effect ( heat4 ,x may be not$ t /ones ( ! int]m$iate type are usually *>act]iz$ by a b&$ or zonal /ructure sugge/+ a want ( homog5eity4 ,! !ory has be5 advanc$ t zircon conta9s an unkn[n elem5t :i* has n yet be5 sep>at$ f zirconium4 ,zircon ( ! fir/ type fav\rs gre51 sky-blue1 & gold5-yell[ col\rs2 honey-yell[1 light gre51 blue1 & r$ col\rs *>act]ize ! second type2 & ! int]m$iate /ones are mo/ly yell[i% gre51 cl\dy blue1 & gre54 ,x is ano!r peculi>ity ( zircon t x sometimes %[s 9 ! spectroscope absorption b&s 7p4 #fa71 :i* 7 obs]v$ 9 #ahff by ,*ur*4 ,_m zircons d n exhibit ! b&s at all1 & o!rs only display ! two prom95t b&s 9 ! r$ end ( ! spectrum4 ,( all ! gem-/ones zircon alone approa*es diamond 9 brilliance ( lu/re1 & x also possesses consid]able #8fire'2 x c1 ( c\rse1 be readily di/+ui%$ by its inf]ior h>dness1 b a judgm5t bas$ m]ely on inspection by eye might easily be errone\s4 ,accord+ to ,*ur*1 :o has made a lifelong /udy ( zircon1 ! gre5 & yell[i% /ones ( ! fir/ v>iety emit a brilliant orange light :5 be+ gr\nd on a copp] :eel *>g$ ) diamond du/1 & ! gold5 /ones ( ! int]m$iate type gl[ ) a f9e orange inc&esc5ce 9 ! flame ( a buns5 burn]2 ! latt] ph5om5on is suppos$ to be due to ! pres5ce ( ?oria4 ,! leaf-gre5 /ones almo/ inv>iably %[ a s]ies ( p>allel b&s 9 ! int]ior4 ,zircons v>y f #es4 to #aes4 a c>at1 b exceptional /ones may be wor? m4 ,by f> ! f9e/ /ones come f ,ceylon4 ,! col\rless /ones are !re kn[n z #8,matura diamonds1' & ! hyac9? includes g>net 7hessonite7 ( simil> col\r1 :i* is f\nd ) x 9 ! same gravels4 ,! /ones are always wat]-worn4 ,small hyac9?s & deep-r$ /ones come f ,expailly1 ,auv]gne1 ,france1 & yell[i%-r$ cry/als are f\nd 9 ! ,ilm5 ,m\nta9s1 ,or5burg1 ,russia4 ,rem>kably f9e r$ /ones h be5 discov]$ at ,mudgee1 ,new ,s\? ,wales1 & yell[i%-br[n /ones accompany diamond at ! ,kimb]ley m9es1 ,s\? ,africa4 ,,*apt] ,,xxvii ,,*rysob]yl 7,*rysolite1 ,cat's-,eye1 ,cymophane1 ,alex&rite7 ,*rysob]yl has at times enjoy$ fleet+ popul>ity on acc\nt ( ! excell5t cat's-eyes cut f ! fibr\s /ones1 & 9 ! =m ( alex&rite x meets ) a /eadi]1 if /ill limit$1 dem&4 ,x is a gem-/one t is seldom met ) 9 ord9>y jewell]y1 al?\gh its consid]able h>dness befits x = all su* purposes4 ,*rysob]yl is 9 composition an alum9ate ( b]yllium correspond+ to ! =mula ,be,al#b,o#d1 & is !re=e closely ak9 to sp9el4 ,x usually conta9s "s f]ric & *romic oxides 9 place ( alum9a1 & f]r\s oxide 9 place ( b]yllia1 & x is to ^! accessory con/itu5ts t its t9ts are due4 ,o!r gem-/ones conta9+ ! uncommon elem5t b]yllium are ph5akite & b]yl4 ,pale yell[i% gre51 ! commone/ col\r1 is suppos$ to be caus$ by f]r\s oxide2 su* /ones are kn[n to jewell]s z *rysolite 7,plate ,,xxvii1 ,fig4 #ab74 ,cat's-eyes 7,plate ,,xxix1 ,fig4 #a7 h (t5 also a br[ni% %ade ( gre54 ,! blui% gre5 & d>k olive-gre5 /ones kn[n z alex&rite 7,plate ,,xxvii1 ,figs4 #aa1 #ac7 diff] 9 appe>ance s m>k$ly f _! fair] si/]s t _! common p>5tage seems almo/ incr$ible4 ,! dull fires t gl[ )9 !m1 & ! curi\s *ange t comes ov] !m at night1 add a t\* ( my/]y to ^! d>k /ones4 ,*romic oxide is held responsible = _! col\r4 ,! cat's-eyes are1 ( c\rse1 always cut en cabo*on1 b o!rwise *rysob]yl is facet$4 ,! "n ( ! species is compos$ ( two ,greek words1 1 gold51 & 1 b]yl1 & etymologically m correctly def9es ! light]-col\r$ /ones1 :i* 71 inde$1 at "o "t ! only k9d kn[n4 ,*rysolite f 1 gold51 & 1 /one1 has mu* ! same significance4 ,?is "n is pref]r$ by jewell]s1 b 9 sci5ce x is appli$ to an entirely diff]5t species1 :i* is kn[n 9 jewell]y z p]idot4 ,cymophane1 f 1 wave1 & 1 appe>1 ref]s to ! peculi> opalesc5ce *>act]i/ic ( cat's-eyes2 x is sometimes us$ to designate ^! /ones1 b does n f9d a place )9 ! vocabul>y ( jewell]y4 ,alex&rite is nam$ aft] ,alex&] ,,ii1 ,cz> ( ,russia1 because x fir/ came to light on 8 bir?day4 ,t circum/ance1 c\pl$ ) its display ( ! national col\rs1 gre5 & r$1 & its at "o "t re/riction to ! m9+ di/rict ne> ,ekat]9burg1 r5d]s x de> to ! he>t ( all loyal ,russians4 ,*rysob]yl cry/allizes 9 ! or?orhombic sy/em1 & occurs 9 r dull1 complex cry/als1 :i* are sometimes s rem>kably tw9n$1 especially 9 ! v>iety call$ alex&rite1 z to simulate hexagonal cry/als4 ,9 keep+ ) ! cry/all9e symmetry x is d\bly refractive & biaxial1 hav+ two directions ( s+le refraction4 ,! lea/ & ! greate/ ( ! pr9cipal indices ( refraction may h any values betwe5 #agdb & #agdi1 & #agej & #ageg1 respectively1 ! maximum am\nt ( d\ble refraction rema9+ always ! same1 namely1 #jjji4 ,! mean pr9cipal refractive index is close to ! lea/2 ! sign ( ! d\ble refraction is !re=e positive1 & ! %ad[-edge correspond+ to ! l[] index1 z se5 9 ! refractomet]1 has little1 if any1 p]ceptible motion :5 ! /one is rotat$4 ,! conv]se is ! case ) corundum2 ! sign is negative1 & x is ! %ad[-edge correspond+ to ! great] refractive index t rema9s unalt]$ 9 position on rotation ( ! /one4 ,?is te/ w\ld suffice to sep>ate *rysob]yl f yell[ corundum1 ev5 if ! refractive indices ( ! =m] 7 n s5sibly l[] ?an ^? ( ! latt]4 ,also1 ! di*roism ( *rysolite is /rong] ?an t ( yell[ sapphires4 ,9 alex&rite ?is ph5om5on is mo/ prom95t2 ! absorptive t9ts1 columb9e-r$1 orange1 & em]ald-gre51 correspond+ to ! ?ree pr9cipal optical directions1 are 9 /rik+ contra/1 & ! fir/ diff]s s mu* f ! intr9sic col\r ( ! /one z to be obvi\s to ! unaid$ eye1 & is ! cause ( ! r$ t9ts visible 9 a cut /one4 ,! curi\s *ange 9 col\r ( alex&rite1 f leaf-gre5 to raspb]ry-r$1 t takes place :5 ! /one is se5 by artificial light1 is due to a diff]5t cause1 z has be5 po9t$ out above 7p4 #ed74 ,! effect is illu/rat$ by ,figs4 #aa1 #ac on ,plate ,,xxvii1 :i* repres5t a f9e ,ceylon /one z se5 by daylight & artificial light2 ! influ5ce ( di*roism may be notic$ 9 ! =m] picture4 ,! specific gravity ( *rysob]yl v>ies f #cfh to #cgh4 ,9 h>dness ?is species ranks above sp9el & comes next to corundum1 be+ giv5 ! symbol #h on ,mohs's scale4 ,c]ta9 /ones conta9 a multitude ( microscopic *annels arrang$ 9 p>allel position4 ,:5 ! /ones are cut ) _! r\nd$ surface p>allel to ! *annels1 a broadi% b& ( light is visible runn+ across ! /one at "r angles to !m1 & sugge/s ! pupil ( a cat's eye1 :5ce ! common "n = ! /ones4 ,! fact t ! *annels are holl[ causes an opalesc5ce1 :i* is abs5t f ! qu>tz cat's-eye4 ,! mo/ important locality = ! yell[i% *rysob]yl is ! ri* di/rict ( ,m9as ,novas1 ,m9as ,g]aes1 ,brazil1 :]e x occurs 9 ! =m ( pebbles1 & excell5t mat]ial is also suppli$ by ,ceylon1 9 bo? cry/als & r\nd$ pebbles4 ,o!r places = *rysolite are ,haddam1 ,connecticut1 & ,gre5field1 ,s>atoga ,c\nty1 ,new ,york1 9 ! ,unit$ ,/ates1 & rec5tly 9 ! gem-gravels ne> ! ,somabula ,=e/1 ,rhodesia4 ,ceylon supplies "s ( ! be/ cat's-eyes4 ,alex&rite 0 fir/ discov]$1 z already /at$1 at ! em]ald m9es ne> ,ekat]9burg1 9 ! ,urals2 b ! supply is n[ ne>ly exhau/$4 ,a poor] quality comes f ,tak[aja1 also 9 ! ,urals4 ,good alex&rite has come to light 9 ,ceylon1 & mo/ ( ! /ones t are plac$ on ! m>ket at ! pres5t day h emanat$ f t isl&4 ,! ,ceylon /ones rea* a consid]able size1 (t5 z mu* z f #aj to #bj c>ats 9 weight2 ! ,russian /ones h a bett] col\r & are m beautiful1 b !y are less transp>5t1 & r>ely exce$ a c>at 9 weight4 ,good *rysolite may be wor? f #ajs4 to #b a c>at1 & cat's-eye runs f #a to #d a c>at1 dep5d+ ^u ! quality4 ,alex&rites meet ) a /eady dem& 9 ,russia1 & f9e /ones are sc>ce2 flawless /ones ab\t a c>at 9 weight are wor? z mu* z #cj a c>at1 & ev5 q ord9>y /ones fet* #d a c>at4 ,f ,ceylon1 t int]e/+ home ( gems1 h orig9at$ "s magnific5t *rysob]yls1 includ+ a sup]b *rysolite1 #hj c>ats 9 weight1 & ano!r1 a spl5did br[ni% yell[ 9 col\r & v ev5 9 t9t1 & two l>ge alex&rites1 gre5 9 daylight & a ri* r$ by night1 weigh+ #fc & #bh-bc_/cb c>ats4 ,! f9e/ cut *rysolite exi/+ is probably ! "o exhibit$ 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory74 ,absolutely flawless & weigh+ #dc c>ats1 x 0 =m]ly conta9$ 9 ! fam\s ,hope collection1 & is describ$ on page #ef & figur$ on ,plate ,,xxi ( ! catalogue prep>$ by ,b4 ,h]tz1 :i* 0 publi%$ 9 #ahci2 ! weight !re giv5 includes ! brilliants & ! r+ 9 :i* x 0 m\nt$4 ,x is %[n1 ab\t actual size1 9 ,plate ,,xxvii1 ,fig4 #ab4 ,a magnific5t cat's-eye1 #cee by #ce mm4 9 size1 :i* also =m$ "p ( ! ,hope collection1 0 includ$ 9 ! cr[n jewels tak5 f ! ,k+ ( ,k&y 9 #ahae4 ,! cry/all9e m>k+s 9 ! cut /one are s arrang$ t ! l[] half %[s an alt> ov]hung by a tor*4 ,! /one has be5 fam\s 9 ,ceylon = _m ages4 ,x 0 set 9 gold ) rubies cut en cabo*on4 ,two f9e ,ceylon alex&rites ( exceptional m]it1 weigh+ #db & #bf c>ats1 are also exhibit$ 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory74 ,! =m] is illu/rat$ 9 ,plate ,,xxvii1 ,figs4 #aa1 #ac1 z se5 9 daylight & 9 artificial light4 ,,*apt] ,,xxviii ,,qu>tz 7,rock-,cry/al1 ,ame?y/1 ,citr9e1 ,cairngorm1 ,cat's-,eye1 ,tig]'s-,eye7 ,al?\gh ! commone/ &1 9 its natural =m1 ! mo/ easily recognizable ( m9]al sub/ances1 qu>tz nev]!less holds a n inconspicu\s position among gem-/ones1 because1 z ame?y/ 7,plate ,,xxvii1 ,fig4 #g71 x provides /ones ( ! f9e/ violet col\r2 moreov]1 ! yell[ qu>tz 7,plate ,,xxvii1 ,fig4 #e7 s ably vies ) ! true topaz t x is univ]sally kn[n to jewell]s by ! "n ( ! latt] species1 & is too (t5 conf\nd$ ) x1 & ! lu/r\s1 limpid rock-cry/al ev5 aspires to ! local title ( #8diamond4' ,= all purposes :]e a violet or yell[ /one is requir$1 qu>tz is admirably suit$2 x is h>d & durable1 & x has ! m]it1 or possibly to "s m9ds ! drawback1 ( be+ mod]ate 9 price4 ,despite its comp>ative lack ( #8fire1' rock-cry/al might replace pa/e 9 r+s & buckles ) consid]able advantage f ! po9t ( view ( durability4 ,! *atoyant qu>tz1 especially 9 ! =m kn[n z tig]'s-eye1 w = beauty be> comp>ison ) ! true cat's-eye1 :i* is a v>iety ( *rysob]yl4 ,except t cat's-eye is cut en cabo*on1 qu>tz is /ep- or sometimes brilliant-cut4 ,rank+ ) corundum next to diamond z ! simple/ 9 composition ( ! gem-/ones1 qu>tz is ! cry/alliz$ =m ( silica1 oxide ( silicon1 correspond+ to ! =mula ,si,o#b4 ,:5 pure1 x is entirely devoid ( ! fa9te/ trace ( col\r & absolutely wat]-cle>4 ,su* /ones are call$ rock-cry/al1 & x is easy to und]/& :y 9 e>ly days x 0 suppos$ to repres5t a =m ( petrifi$ wat]4 ,x is ^! brilliant1 transp>5t /ones t are1 :5 small1 kn[n 9 _m localities z #8diamonds4' ,be=e ! manufacture ( glass 0 discov]$ & br\ght to p]fection1 rock-cry/al 0 9 consid]able use = fa%ion+ into cups1 vases1 & s =?4 ,! beautiful t9ts *>act]iz+ qu>tz are due to ! usual metallic oxides4 ,to manganese is giv5 ! cr$it ( ! sup]b purple or violet col\r ( ame?y/1 :i* v>ies consid]ably 9 dep?4 ,jewell]s are incl9$ to di/+ui% ! deep-col\r$ /ones ) ! prefix #8ori5tal1' b ! practice is to be deprecat$1 s9ce x might lead to confusion ) ! true ori5tal ame?y/1 :i* is a purple sapphire1 "o ( ! r>e/ v>ieties ( corundum4 ,qu>tz ( a yell[ hue is prop]ly call$ citr9e1 b1 z already /at$1 jewell]s habitually pref] ! "n #8topaz' = x1 & di/+ui% ! true topaz by ! prefix ,brazilian--n a v happy t]m1 s9ce bo? ! yell[ topaz & ! yell[ qu>tz occur pl5tifully 9 ,brazil4 ,sometimes ! yell[ qu>tz is t]m$ occid5tal1 ,spani%1 or false topaz4 ,/ones ) a br[ni% or smoky t+e ( yell[ are call$ cairngorm1 or ,scot* topaz4 ,! col\r ( ! yell[ /ones is d\btless due to a trace ( f]ric oxide4 ,/ones ( a smoky br[n col\r are kn[n z smoky-qu>tz4 ,rose-qu>tz1 :i* is rose-r$ or p9k 9 col\r & hazy 9 texture1 is comp>atively r>e2 /range to say1 x has nev] be5 f\nd 9 di/9ct cry/als4 ,! t9t1 :i* may be due to titanium1 is fugitive1 & fades on exposure to /rong sunlight4 ,9 milky qu>tz1 z ! "n sugge/s1 ! int]ior is s hazy z to imp>t to ! /one a milky appe>ance4 ,x has frequ5tly happ5$ t qu>tz has cry/alliz$ aft] ! =mation ( o!r m9]als1 ) ! result t ! latt] are f\nd inside x4 ,prase1 or "m-(-em]ald1 :i* at "o "t 0 suppos$ to be ! "m-rock ( em]ald1 is a qu>tz col\r$ leek-gre5 by act9olite fibres 9 ! int]ior4 ,specim5s conta9+ hair-l fibres ( rutile--! s-call$ fl*es d'am\r--are common 9 m9]al collections1 & are sometimes to be se5 work$4 ,:5 enclos+ a massive1 light-col\r$1 fibr\s m9]al1 ! /ones h a *atoyant effect1 & display1 :5 suitably cut1 a f9e cat's-eye effect2 9 tig]'s-eye ! enclos$ m9]al is crocidolite1 an asbe/os1 ! orig9al blue hue ( :i* has be5 *ang$ to a f9e gold5-br[n by oxidation4 ,qu>tz :i* conta9s scales ( mica1 hematite1 or o!r flaky m9]al has a vivid spangl$ appe>ance1 & is kn[n z av5tur9e2 x has occasionally be5 employ$ = broo*es or simil> articles ( jewell]y4 ,ra9b[-qu>tz1 or iris1 is a qu>tz :i* conta9s cracks1 ! *romatic effect be+ ! result ( ! int]f]5ce ( light reflect$ f !m2 x has be5 artificially produc$ by heat+ ! /one & sudd5ly cool+ x4 ,! "n ( ! species is an old ,g]man m9+ t]m ( unkn[n mean+ :i* has be5 9 g5]al use 9 all languages s9ce ! sixte5? c5tury4 ,ame?y/ is d]iv$ f 1 n drunk51 possibly f a fooli% notion t ! we>] 0 exempt f ! usual consequ5ces ( unre/ra9$ libations4 ,pl9y sugge/s z an alt]native explanation t its col\r approximates to1 b does n q rea*1 t ( w9e4 ,av5tur9e1 f av5tura1 an accid5t1 0 fir/ appli$ to glass spangl$ ) copp]1 ! effect be+ said to h be5 accid5tally discov]$ ow+ to a numb] ( copp] fil+s fall+ into a pot ( molt5 glass 9 a ,v5etian factory4 ,illu/ration3 ,,fig4 #gi4--,qu>tz ,cry/al4 ,qu>tz belongs to ! hexagonal sy/em ( cry/all9e symmetry1 & cry/allizes 9 ! famili> six-sid$ prisms t]m9at$ by six incl9$1 (t5 triangul>1 faces 7,fig4 #gi72 tw9s are common1 ?\gh !y are n always obvi\s f ! outw>d developm5t4 ,9 accordance ) ! symmetry ! refraction is d\ble1 & !re is "o direction ( s+le refraction1 namely1 t p>allel to ! edge ( ! prism4 ,! ord9>y refractive index has ! value #aedd1 & ! extraord9>y #aeec1 & s9ce ! latt] is ! great]1 ! sign ( ! d\ble refraction is positive4 ,! d\ble refraction is small 9 am\nt1 b is l>ge en\gh to enable ! app>5t d\bl+ ( c]ta9 ( ! opposite edges ( a facet$ /one to be p]ceptible :5 view$ ) a l5s ?r\gh ! table-facet4 ,! di*roism ( ! deep-col\r$ /ones is q di/9ct4 ,qu>tz has only ab\t ! same am\nt ( col\r disp]sion z ord9>y glass1 & lacks1 !re=e1 #8fire4' ,! application ( /rong heat t5ds1 z usual1 to weak5 or drive (f ! col\r4 ,?us ! d5se smoky-qu>tz f\nd 9 ,spa91 ,brazil1 & else:]e is conv]t$ into /ones ( a col\r v>y+ f light yell[ to r$di% br[n accord+ to ! am\nt & duration ( ! application4 ,9 ! case ( ame?y/ ! col\r is *ang$ to a deep orange1 or entirely driv5 (f if ! temp]ature be high en\gh4 ,its d5sity is v con/ant1 v>y+ only f #bfed to #bffj2 ! pure/ /ones are ! lighte/4 ,to x has be5 assign$ ! symbol #g on ,mohs's scale ( h>dness4 ,to physici/s qu>tz is "o ( ! mo/ int]e/+ ( m9]als because ( its p[] ( rotat+1 to an ext5t dep5d+ ^u ! ?ickness ( ! section1 ! plane ( pol>ization ( a beam ( light trav]s+ x 9 a direction p>allel to ! prism edge4 ,x appe>s1 moreov]1 f a /udy ( ! pyro-electric & g5]al physical *>act]s1 t its molecul> /ructure has a helical arrangem5t1 :i*1 l all screws1 may h a "r- or left-h&$ "*4 ,ame?y/ is1 9 fact1 inv>iably compos$ ( sep>ate tw9 individuals1 alt]nately "r- & left-h&$2 9 "s rem>kable cry/als ! section at "r angles to ! prism edge is compos$ ( triangul> sectors1 alt]nately ( diff]5t h&s & ( diff]5t t9ts--purple & :ite4 ,to ! tw9n+ is due ! rippl$ fracture & ! fea!ry inclusions s *>act]i/ic ( ame?y/4 ,besides its use = ornam5tal purposes1 qu>tz f9ds a place z ! mat]ial = l5ses int5d$ = delicate photographic "w1 because its transp>5cy to ! ultra-violet light is s mu* great] ?an t ( glass4 ,spectacle l5ses made ( x are 9 dem&1 because !y are n liable to scrat*es1 & reta91 !re=e1 _! poli% indef9itely4 ,:5 fus$ 9 ! oxyhydrog5 flame1 qu>tz becomes a silica glass1 ( specific gravity #bb & h>dness #e on ,mohs's scale1 :i* has prov$ ( great s]vice = laboratory w>e1 because x )/&s sudd5 & unequal heat+ )\t any dang] ( fracture2 x has also 9 f9e ?reads be5 invaluable = delicate torsion "w1 because x acquires n ! smalle/ am\nt ( p]man5t twi/1 9 ?is respect be+ sup]ior to ! f9e/ silk ?reads4 ,cle> rock-cry/al fet*es little m ?an ! co/ ( ! cutt+2 citr9e & ame?y/ are wor? f #as4 to #es4 a c>at1 dep5d+ ^u ! quality & size ( ! /one2 smoky-qu>tz is practically valueless2 rose-qu>tz realizes less ?an #as4 a c>at2 & ! value ( cat's-eye is also small--only #as4 to #bs4 #f;d4 a c>at4 ,tig]'s-eye at "o "t comm&$ z mu* z #bes4 a c>at1 b ! supply exce$$ ! dem&1 ) ! consequ5t collapse 9 ! price4 ,beautiful1 brilliant1 & limpid rock-cry/al is f\nd 9 v>i\s p>ts ( ! _w3 9 ! ,swiss ,alps1 at ,b\rg d',oisans 9 ! ,dauph9 ,alps1 ,france1 9 ! fam\s ,c>r>a m>ble1 9 ! ,m>m>os ,comitat ( ,hung>y1 & 9 ! ,unit$ ,/ates1 ,brazil1 ,madagasc>1 & ,japan4 ,small lu/r\s /ones1 kn[n 9 _! localities z #8,isle ( ,wight1' #8,corni%1' or #8,bri/ol diamonds1' are f\nd 9 our own c\ntry4 ,brazil supplies /ones out ( :i* h be5 cut ! cle> balls us$ 9 cry/al-gaz+4 ,! f9e/ ame?y/s come f ,brazil--especially ! ,/ate ( ,rio ,gr&e d ,sul--& f ,uruguay1 ,india1 & ! gem-gravels ( ,ceylon2 good /ones also occur at ,ekat]9burg1 9 ! ,ural ,m\nta9s4 ,a spl5did ,brazilian ame?y/1 weigh+ #ccd c>ats1 & two ,russian /ones--"o hexagonal 9 cont\r1 weigh+ #hh c>ats1 & ! o!r1 a deep purple 9 col\r ) a circul> table1 weigh+ #gc c>ats--are exhibit$ 9 ! ,briti% ,museum 7,natural ,hi/ory74 ,cairngorm is kn[n f ! place ( t "n 9 ,banff%ire1 ,scotl&1 :5ce f9e specim5s h emanat$2 x is a gem mu* valu$ 9 t c\ntry4 ,f9e cairngorm has also orig9at$ f ,pike's ,peak1 ,colorado4 ,spl5did yell[ /ones h _h _! bir? 9 ! ,/ates ( ,m9as ,g]aes1 ,so ,paulo1 & ,goyz1 ( ,brazil--especially 9 ! la/4 ,! f9e ,spani% smoky-qu>tz1 :i*1 z already /at$1 turns yell[ on heat+1 comes f ,h9ojosa1 9 ! ,prov9ce ( ,cordova4 ,! delicate rose-qu>tz is kn[n at ,bod5mais 9 ,bav>ia1 ,p>is 9 ,ma9e1 ,unit$ ,/ates1 & ,ekat]9burg 9 ! ,ural ,m\nta9s4 ,! f9e/ cat's-eyes are f\nd 9 ,india & ,ceylon1 & are high 9 fav\r ) ! natives4 ,gre5i% /ones ( an inf]ior quality are br\ght f ! ,fi*telgebirge 9 ,bav>ia1 & are sold z #8,hung>ian cat's-eyes1' despite ! fact t no su* /one occurs 9 ,hung>y--ano!r in/ance ( jewell]s' disda9 = accuracy4 ,tig]'s-eye occurs 9 consid]able quantity 9 ! neighb\rhood ( ,griquat[n1 ,griqual& ,we/1 ,s\? ,africa4 ,a silicifi$ crocidolite1 9 :i* ! blue col\r is reta9$1 comes also f ,salzburg1 & is kn[n z sapphire- or azure-qu>tz1 or sid]ite4 ,c]ta9 ( ! pebbles f\nd on ! sea%ore ( our coa/s1 especially (f ! ,isle ( ,wight & ,nor? ,wales1 cut into attractive1 cle> /ones1 m or less yell[ 9 col\r2 b examples suitable = ! purpose are n s num]\s z might be suppos$1 & d n rew>d any casual se>*4 ,les affaires sont les affaires4 ,! local lapid>y1 in/ead ( expla9+ t ! pebbles br\ght to him are n wor? cutt+1 f9ds x m conv5i5t & pr(itable to sub/itute = !m o!r1 inf]ior & badly cut1 /ones1 b\ght by ! gross1 or ev5 pa/e /ones2 ! cu/om]1 on ! o!r h&1 is cont5t$ ) a pretty bauble1 & is n grateful = ! in=mation t x might h be5 obta9$ = a fraction ( ! sum paid4 ,,*apt] ,,xxix ,,*alc$ony1 ,,agate1 ,,etc4 ,*alc$ony & agate1 & _! endless v>ieties1 are compos$ ma9ly ( silica1 b ! sep>ate individual cry/als are s small z to be invisible to ! unaid$ eyesight1 & occasionally are s extremely m9ute t ! /ructure is almo/ amorph\s4 ,! col\r & appe>ance v>y greatly1 dep5d+ ^u ! impurities conta9$ 9 ! /one1 &1 s9ce bo? h be5 made a crit]ion = diff]5tiation ( types1 a ho/ ( names h come into use1 none ( :i* are susceptible ( /rict def9ition4 ,on ! :ole1 ^! /ones may be divid$ into two gr\ps3 *alc$ony1 9 :i* ! /ructure is concretion>y & ! col\r comp>atively uni=m1 & agate1 9 :i* ! arrangem5t takes ! =m ( b&s1 v>y+ greatly 9 t9t & col\r4 ,! refraction1 ?\gh d\ble 9 ! individual1 is irregul> ov] ! /one z a :ole1 & ! indices approximate to #aeej4 ,! specific gravity ranges f #bfb to #bfd1 dep5d+ ^u ! impurities pres5t4 ,! degree ( h>dness is ab\t ! same z t ( qu>tz1 namely1 #g on ,mohs's scale4 ,all k9ds are m or less por\s1 & /ones ( a dull col\r are !re=e artificially t9t$ aft] be+ work$4 ,! t]m *alc$ony1 d]iv$ f ! "n ( a t[n 9 ,asia ,m9or1 is usually conf9$ to /ones ( a greyi% t+e4 ,/ones artificially col\r$ an em]ald gre5 h be5 cut & put ^u ! m>ket z #8em]ald9e4' ,c>nelian is a cle> r$ *alc$ony1 & s>d is some:at simil>1 b br[ni% 9 t9t4 ,*rysoprase is apple-gre5 9 col\r1 nickel oxide be+ suppos$ to be ! ag5t4 ,prase 7cf4 p4 #bdj71 :i* is a dull leek-gre5 9 hue1 may also 9 "p be ref]r$ "h2 ! "n comes f 1 a leek4 ,plasma1 :i* may h ! same d]ivation1 is a bright] leek-gre54 ,jasp] is a *alc$ony col\r$ blood-r$ by iron oxide1 :ile blood/one is a gre5 *alc$ony spott$ ) jasp]2 !y are popul> /ones = signet r+s4 ,fl9t1 an opaque *alc$ony1 breaks ) a %>p cutt+ edge1 & 0 mu* 9 reque/ ) e>ly man z a tool or a weapon2 its prop]ty ( giv+ sp>ks :5 /ruck ) /eel r5d]$ x invaluable be=e ! inv5tion ( mat*es4 ,horn/one is some:at simil>1 b m brittle1 :ile *]t is a fl9ty rock4 ,agate1 nam$ aft] ! riv] ,a*ates 9 ,sicily1 :]e x 0 f\nd at ! "t ( ,!ophra/us1 has a peculi> b&$ /ructure1 ! b&s be+ usually irregul> 9 %ape1 foll[+ ! configuration ( ! cavity 9 :i* x 0 =m$4 ,moss-agate1 or mo*a-/one1 conta9s moss-l inclusions ( "s fibr\s m9]al4 ,onyx is an agate ) regul> b&s1 ! lay]s hav+ %>ply diff]5t col\rs2 :5 black & :ite1 x has1 9 days gone by1 be5 employ$ = cameos4 ,s>donyx is simil> 9 /ructure1 b r$ & :ite 9 col\r4 ,agate is us$ 9 delicate balances = support+ ! /eel knife-edges ( ! balance itself & ( ! panhold]s1 & is l>gely employ$--especially :5 artificially col\r$--= umbrella h&les & simil> articles4 ,*alc$ony & agate are f\nd ! :ole _w ov]1 b ,india1 & p>ticul>ly ,brazil1 are not$ = _! f9e c>nelians & agates4 ,,*apt] ,,xxx ,,opal 7,:ite ,opal1 ,black ,opal1 ,fire-,opal7 ,t opal 9 e>ly times excit$ ke5 admiration is evid5t f ,pl9y's en?usia/ic description ( ^! /ones3 8,= 9 !m y %all see ! burn+ fire ( ! c>buncle1 ! glori\s purple ( ! ame?y/1 ! gre5 sea ( ! em]ald1 all glitt]+ toge!r 9 an incr$ible mixture ( light40 ,dur+ mu* ( la/ c5tury1 ow+ to ! fooli% sup]/ition t ill-luck dogs ! foot/eps ( ! we>]1 ! species lay "u a cl\d1 :i* has ev5 n[ n q disp]s$1 b ex]cises a prejudicial effect ^u ! =tunes ( ! /one4 ,x has1 h[ev]1 rec5tly attract$ consid]able att5tion ow+ to ! discov]y ( ! spl5did black opals 9 ,au/ralia2 at "o mom5t black ) ! d>kness ( night1 at ! next by a *ance movem5t gl[+ ) vivid crimson flame1 su* /ones may ju/ly be consid]$ ! mo/ rem>kable 9 mod]n jewell]y4 ,at ! pres5t day opal is divid$ by jewell]s r\ghly into two ma9 gr\ps3 #8:ite' 7,plate ,,xxvii1 ,fig4 #f7 & #8black' 7,plate ,,xxvii1 ,fig4 #i71 accord+ z ! t9t is light or d>k1 fire-opal 7,plate ,,xxvii1 ,fig4 #aj7 /&+ 9 a sep>ate category4 ,opal diff]s f ! re/ ( ! pr9cipal gem-/ones 9 be+ n a cry/all9e body1 b a solidifi$ jelly1 & x dep5ds = its attractiv5ess ^u ! *>act]i/ic play ( col\r1 kn[n1 9 consequ5ce1 z opalesc5ce 7cf4 p4 #ci71 :i* arises f a peculi>ity 9 ! /ructure4 ,opal is ma9ly silica1 ,si,o#b1 9 composition1 b conta9s 9 addition an am\nt ( wat] v>y+ 9 preci\s opal f #f to #aj p] c5t4 ,z ! orig9al jelly cool$1 x became riddl$ ?r\gh\t ) cracks1 :i* 7 aft]w>ds g5]ally fill$ ) opal matt]1 conta9+ a diff]5t am\nt ( wat]1 & !re=e diff]+ slightly 9 refractivity f ! orig9al sub/ance4 ,! /ructure n be+ q homog5e\s1 ea* crack has ! same action ^u light z a soap-film1 & gives rise to precisely simil> ph5om5a2 ! ?9n] & m uni=m ! cracks1 ! great] ! spl5d\r ( ! *romatic display1 ! p>ticul> t9t dep5d+ ^u ! direction 9 :i* ! /one is view$4 ,! cracks 9 c]ta9 opals 7 n fill$ up1 & !re=e conta9 air4 ,su* /ones appe> opaque & devoid ( opalesc5ce until plung$ into wat]2 !y are consequ5tly kn[n z hydrophane1 f 1 wat]1 & 1 to make appe>4 ,ow+ to ! effect ( total-reflection1 light 0 /opp$ on ! hi!r side ( ! cracks be=e !y 7 fill$ ) wat]1 :i* is n f> inf]ior to opal 9 refractivity2 x is surpris+ h[ mu* wat] ^! /ones w absorb4 ,opal is col\rless :5 pure1 b is ne>ly always m or less milky & opaque1 or t9t$ v>i\s dull %ades by f]ric oxide1 magnesia or1 alum9a4 ,! s-call$ black opal is g5]ally a d>k grey or blue1 & v r>ely q black4 ,t ! coloration is n due to ord9>y absorption1 b to ! action ( cracks 9 ! /one1 is %[n by ! fact t ! transmitt$ light is complem5t>y to ! reflect$ light2 ! blue opal is1 = in/ance1 a yell[ :5 held up s t light has pass$ ?r\gh x4 ,9 _m black opals ! opalesc5t mat]ial occurs 9 f> too t9y pieces to be cut sep>ately1 & ! :ole iron-/a9$ matrix is cut & poli%$ & sold "u ! "n #8opal-matrix4' ,! r$di% & orange-col\r$ /ones kn[n z fire-opal h pron\nc$ col\r & only slight milk9ess2 !y display ! cu/om>y opalesc5ce 9 c]ta9 directions4 ,^! /ones are (t5 facet$1 b o!rwise opals are cut en cabo*on1 ei!r flat or /eep--g5]ally ! =m] 9 broo*es & p5dants1 & ! latt] 9 r+s4 ,opal is some:at s(t1 v>y+ f #e to #f on ,mohs's scale1 & is !re=e easily scrat*$4 ,! specific gravity ranges f #baj to #bbj1 & ! refractive index f #addd to #adfd1 ! refraction1 ( c\rse1 be+ always s+le4 ,x is unwise to imm]se opals 9 liquids on acc\nt ( _! porosity4 ,! "n opal comes to u ?r\gh ! ,lat9 opallus1 :i* 0 us$ = ! same species z und]/ood by ! t]m at ! pres5t day1 b ! ^w has a f> old] orig91 :i* has n be5 trac$4 ,! ,romans also call$ ! m9]al pd]os1 ! ,greek =m ( ,cupid1 a "n appli$ to all rosy /ones4 ,! "n ca*olong1 = ! blui%-:ite porcela9 v>iety1 :i* is v por\s & adh]es to ! tongue1 is ( ,t>t> orig92 ! /one is highly valu$ 9 ! ,ea/4 ,! olde/ m9es1 :i* up to q a rec5t date 7 ! only ext5sive deposit ( opal kn[n1 7 at ,cs]w5itsa1 ne> ,ka%au1 9 ,hung>y4 ,f !m 9 all probability emanat$ ! opals kn[n to ! ,romans4 ,! opals f ?is locality 7 g5]ally q small1 & l>ge pieces 7 r>e & comm&$ high prices4 ,! ,hung>y m9es1 h[ev]1 prov$ q unable to compete ) ! ri* fields at ,:ite ,cliffs1 ,new ,s\? ,wales1 9 spite ( ! ef=ts t 7 made to depreciate & exclude f ! m>ket ! new /ones1 & at ! pres5t "t few ( ! opals on ! m>ket come f !m4 ,z s (t5 happ5s1 ! ,:ite ,cliffs deposit 0 discov]$ by accid5t4 ,9 #ahhi a hunt]1 :5 track+ a w\nd$ kang>oo1 *anc$ to pick up an attractively col\r$ opal4 ,! di/rict is s wat]less & =bidd+ t1 b = su* a *ance1 ! opals might h long la9 hidd54 ,!y occur 9 seams 9 deposits ( ,cretace\s ,age 9 a v>iety ( ways1 fill+ cavities 9 rocks or s&/ones1 or cracks 9 wood1 or replac+ wood1 saurian bones1 & "s spiky m9]al1 :i* may h be5 glaub]ite4 ,9 rec5t ye>s1 ano!r ri* deposit 0 discov]$ f>!r nor?1 on bo? sides ( ! b\nd>y betwe5 ,que5sl& & ,new ,s\? ,wales4 ,! field is rem>kable = ! d>kness ( its opals1 :i* are call$ #8black opal' 9 contradi/9ction to ! light]-col\r$ /ones previ\sly kn[n4 ,f ,lightn+ ,ridge 9 ,new ,s\? ,wales come /ones /a9$ deep black :i* q m]it ! designation black opal4 ,! s&/one 9 :i* !y are f\nd is ri* 9 iron1 & ?is is no d\bt responsible = ! deepness ( _! t9t4 ,mexico is not$ = ! fire-opal1 :i* is f\nd at ,esp]anza1 ,qu]et>o1 & ,zimapan2 b o!r k9ds ( opal also are f\nd at ^! places4 ,illu/ration3 ,,plate ,,xxviii ,,opal ,,m9es1 ,,:ite ,,cliffs1 ,,new ,,s\? ,,wales ,! price ( opal v>ies greatly1 accord+ to ! intr9sic col\r & ! uni=mity & brilliance ( ! opalesc5ce4 ,common opal c be b\ght at z l[ a rate z #as4 a c>at1 :ile black opal ranges f #ajs4 to #h a c>at2 b a good d>k /one display+ a flam+ opalesc5ce comm&s a fancy figure1 f9e /ones ( ?is class be+ exce$+ly r>e4 ,fire-opal enjoys only a limit$ popul>ity n[1 ?\gh a few ye>s ago x 0 9 "s dem&2 ! price runs f #bs4 to #ajs4 a c>at4 ,,*apt] ,,xxxi ,,felsp> 7,moon/one1 ,sun/one1 ,labradorite1 ,amazon-,/one7 ,?\gh second to none among m9]als 9 sci5tific int]e/1 :e!r reg>d$ f ! po9t ( view ( _! cry/all9e *>act]s or ! important "p !y play 9 ! =mation ( rocks1 ! gr\p includ$ "u ! g5]al "n felsp> occupies b a humble place 9 jewell]y4 ,x consi/s ( ?ree di/9ct species1 or?oclase1 albite1 & anor?ite1 :i* are silicates ( alum9ium1 & potassium1 sodium1 or calcium1 correspond+ to ! =mulae ,k,al,si#c,o#h1 ,na,al,si#c,o#h1 & ,ca,al#b,si#b,o#h respectively1 & also ( species int]m$iate 9 composition betwe5 albite & or?oclase1 or albite & anor?ite4 ,:ile diff]+ 9 cry/all9e symmetry1 all are *>act]iz$ by two directions ( cleavage :i* are ne>ly at "r angles to "o ano!r4 ,! d\ble refraction1 :i* is slight 9 am\nt1 is biaxial 9 "* & v>iable 9 sign4 ,! values ( ! lea/ & greate/ ( ! indices ( refraction range betwe5 #aeb & #aec1 & #aec & #aee respectively1 ! d\ble refraction at ! same "t v>y+ f #jjjg to #jjab4 ,! specific gravity lies betwe5 #bdh & #bff1 & ! h>dness ranges betwe5 ! degrees #f & #g on ,mohs's scale4 ,moon/one 7,plate ,,xxix1 ,fig4 #d71 :i* is ma9ly pure or?oclase1 alone is at all common 9 jewell]y4 ,x =ms su* an admirable contra/+ frame = l>ge col\r$ /ones t x des]ves great] popul>ity2 no d\bt ! *eapness ( ! /ones militates aga9/ _! prop] appreciation4 ,! milky1 blui% opalesc5ce f :i* !y take _! "n is caus$ by ! reflection ( light at ! ?9 tw9-lamell ( :i* ! /ructure is compos$4 ,!y are always cut m or less /eeply en cabo*on4 ,! f9e/ /ones 7 at "o "t cut f ! felsp> t came f ! ,/4 ,go?>d di/rict 9 ,switz]l& & 0 9 consequ5ce kn[n z adul>ia f ! neighb\r+ ,adul> ,m\nta9s1 some:at incorrectly1 s9ce none occurs at ! latt] locality4 ,at ! pres5t day practically all ! moon/ones on ! m>ket come f ,ceylon4 ,!y run 9 price f #c to #bj p] oz4 7#bh grams74 ,sun/one is a felsp> conta9+ flakes ( hematite or goe?ite :i* imp>t a spangl$ bronze appe>ance to ! /ones4 ,good mat]ial occurs 9 p>ts ( ,norway4 ,! rem>kable %e5 ( labradorite or blue felsp> has its orig9 9 ! int]f]5ce ( light at lamell> surfaces 9 ! int]ior2 ! uni=mity ( ! col\r ov] comp>atively l>ge areas te/ifies to ! regul>ity ( ! lamell> arrangem5t4 ,! f9e/ specim5s 7 br\ght f ! ,isle ( ,/4 ,paul (f ! coa/ ( ,labrador1 :]e !y 7 fir/ discov]$ 9 #aggj2 l>ge masses also occur on ! coa/ itself4 ,amazon-/one is an opaque gre5 felsp> :i* occurs 9 ! ,ilm5 ,m\nta9s1 ,or5burg1 ,russia1 & at ,pike's ,peak1 ,colorado1 ,unit$ ,/ates4 ,x obta9s its "n f ! ,amazon ,riv]1 :]e1 h[ev]1 none has ev] be5 f\nd2 !re may h be5 "s confusion ) a jade or simil> /one4 ,occasionally cle> col\rless felsp> has be5 facet$1 & !n closely resembles rock-cry/al4 ,a c>eful det]m9ation ( ! refractive indices & ! specific gravity s]ves to discrim9ate betwe5 !m4 ,illu/ration3 ,,plate ,,xxix #a4 ,,cat',s ,,eye #b4 ,,p]idot #c4 ,,p]idot #d4 ,,moon/one #e4 ,,hessonite #f4 ,,pyrope #g4 ,,demantoid #h4 ,,alm&9e #i4 ,,spodum5e #aj4 ,,kunzite #aa4 ,,hidd5ite #ab4 ,,zircon #ac4 ,,zircon #ad4 ,,zircon #ae4 ,,&alusite #af4 ,,nephrite #ag4 ,,turquoise #ah4 ,,jadeite ,,gem-,,/ones ,,*apt] ,,xxxii ,,turquoise1 ,,odontolite1 ,,v>iscite ,( all ! opaque /ones turquoise 7,plate ,,xxix1 ,fig4 #ag7 alone f9ds a prom95t place 9 jewell]y & c aspire to rank ) ! preci\s /ones4 ,! col\r v>ies f a sky-blue or a gre5i% blue to a yell[i% gre5 or apple-gre54 ,only ! =m] t9ts1 :i* are at ! same "t ! r>]1 are 9 g5]al dem&1 & !y possess ! great advantage ( h>moniz+ ) ! t9t ( ! gold sett+4 ,! blue col\rs are1 especially 9 ! case ( ! ,sib]ian /ones1 by no means p]man5t1 & fade 9 c\rse ( "t4 ,turquoise is amorph\s & seldom cry/all9e1 & is !re=e some:at por\s2 x %\ld consequ5tly nev] be imm]s$ 9 liquids or be contam9at$ ) greasy & dirty matt] le/ ! dread$ *ange ( col\r be br\ght ab\t4 ,! /ones are transluc5t 9 ?9 sections1 & a good obs]vation is possible ) ! refractomet] if ! back ( ! /one is flat & poli%$1 s9ce only ! section imm$iately adjac5t to ! in/rum5t is conc]n$2 ! refractive index is ab\t #afa4 ,! specific gravity v>ies f #bge to #bhi4 ,turquoise has a h>dness ( slightly "u #f on ,mohs's scale1 & takes a good poli%1 :i* is fairly durable1 s9ce on acc\nt ( ! comp>ative opacity ( ! /ones scrat*es on ! surface are n v noticeable4 ,9 composition x is a complex phosphate ( alum9ium & copp]1 correspond+ to ! =mula ,cu,o,h4#f;,al7,,oh7#b4;,h#e47,,po#d7d1 ) f]ric oxide replac+ "s alum9a4 ,! blue col\r is due to ! copp] con/itu5t1 & ! pr$om9ance ( iron may cause ! gre5i% %ades2 b ! wat] conta9$ 9 ! /ones plays no mean "p1 s9ce !y turn a dirty gre5 :5 x is driv5 (f4 ,! fad$ col\r c sometimes be re/or$ by imm]sion ( ! /one 9 ammonia & subsequ5t application ( grease1 b ! effect is n la/+4 ,attempts are sometimes made to improve inf]ior /ones by impregnat+ !m ) ,b]l9 blue1 b ) only qualifi$ success4 ,turquoises are said to be affect$ by ! p]spiration f ! sk94 ,! "n ( ! species comes f a ,fr5* ^w mean+ ,turki%1 & arises f ! fact t ! gem-/one fir/ rea*$ ,europe by way ( ,turkey4 ,ano!r1 b less obvi\s1 sugge/ion is t x is d]iv$ f ! ,p]sian "n = ! species1 piruzeh4 ,our turquoise & o!r phosphates ( simil> appe>ance 7 probably kn[n to ,pl9y "u ! ?ree names callais1 calla9a1 & callaica4 ,! f9e/ turquoise /ill comes f ! fam\s m9es ne> ,ni%apur 9 ! ,p]sian prov9ce ( ,khorassan1 :]e x 0 kn[n 9 v anci5t times2 x is f\nd ) limonite fill+ ! cracks & cavities 9 a brecciat$ porphyritic tra*yte4 ,pieces ( ! turquoise & limonite f "h are sometimes cut )\t removal ( ! latt]1 & sold z #8turquoise-matrix1' :5 ! preci\s /ones are too t9y to be wor? sep>ate work+4 ,x also occurs at ,s]bl 9 ! ,s9ai ,p59sula4 ,among ! m rec5t localities may be m5tion$ ,los ,c]illos ,m\nta9s1 ,new ,mexico2 ,si]ra ,nevada1 ,nevada1 :]e pale blue & gre5 /ones are f\nd2 ,san ,b]n>d9o ,c\nty1 ,cali=nia1 :]e aga9 ! /ones are r pale2 & ,arizona1 :]e x occurs 9 pale gre5i%-blue /ones4 ,"s ( ! /ones t h be5 se5 are n ! true turquoise b odontolite1 or bone turquoise1 :i* consi/s ( ! tee? & bones ( ma/odon or o!r ext9ct animals1 phosphate ( iron be+ ! col\r+ mat]ial4 ,^! /ones may easily be recogniz$ by _! organic /ructure1 :i* is cle>ly visible if view$ ) a /rong l5s or "u ! microscope4 ,moreov]1 odontolite inv>iably conta9s "s calcium c>bonate1 & eff]vesc5ce takes place if x be t\*$ ) hydro*loric acid4 ,turquoise dissolves 9 hydro*loric acid1 b )\t eff]vesc5ce1 & s9ce x conta9s copp]1 a f9e blue col\r is imp>t$ to ! solution by ! addition ( ammonia4 ,odontolite has a high] specific gravity1 #cj to #ce1 b l[] h>dness1 #e on ,mohs's scale4 ,v>iscite1 ! hydrat$ phosphate ( alum9ium1 correspond+ to ! =mula ,al,p,o#d #b;,h#b,o1 is f\nd 9 masses resembl+ a gre5i% turquoise1 b x is mu* s(t]1 be+ only #d on ,mohs's scale4 ,! specific gravity is #bee4 ,r\nd nodul> masses ( v>iscite are f\nd 9 ,utah4 ,,*apt] ,,xxxiii ,,jade ,?\gh n usually acc\nt$ preci\s among ,european nations or 9 ,we/]n civilization 9 g5]al1 jade 0 held 9 extraord9>y e/eem by primitive man1 & 0 fa%ion$ by him into ornam5ts & ut5sils1 (t5 ( consid]able beauty1 & ev5 at ! pres5t day x ranks among ! ,*9ese & ,japanese peoples above all preci\s /ones2 inde$1 ! ,*9ese ^w ,yu & ! ,japanese words ,giyuku or ,tama signify bo? jade & preci\s /ones 9 g5]al4 ,accord+ to ! ,*9ese1 jade is ! prototype ( all gems1 & unites 9 itself ! five c>d9al virtues--,j91 *>ity2 ,gi1 mode/y2 ,yu1 c\rage2 ,ketsu1 ju/ice2 & ,*i1 wisdom4 ,:5 p[d]$ & mix$ ) wat]1 x is suppos$ to be a p[]ful rem$y = all k9ds ( int]nal disord]s1 to /r5g!n ! frame & prev5t fatigue1 to prolong life1 &1 if tak5 9 suffici5t quantity j be=e dea?1 to prev5t decomposition4 ,jade is a g5]al t]m t includes prop]ly two di/9ct m9]al species1 nephrite or gre5/one1 & jadeite1 :i* are v simil> 9 appe>ance1 bo? be+ fibr\s & t\gh 9 texture1 & m or less gre5i% 9 col\r2 b x is also appli$ to o!r species su* z saussurite1 cali=nite1 b[5ite1 & plasma1 :i* h some:at simil> *>act]s4 ,! ^w jade is a corruption ( ! ,spani% pietra di hijada1 kidney-/one1 9 allusion to its suppos$ efficacy 9 diseases ( t organ4 ,nephrite or gre5/one 7,plate ,,xxix1 ,fig4 #af7 is ! common] ( ! two jades4 ,x is closely alli$ to ! m9]al hornbl5de1 a silicate ( magnesium1 iron1 & calcium correspond+ to ! =mula ,ca7,mg1,fe7#c7,si,o#c7d1 ! magnesia be+ replaceable by f]r\s oxide4 ,microscopic exam9ation %[s t ! /ructure consi/s ( innum]able indep5d5t fibres foliat$ or matt$ toge!r1 ! =m] "* giv+ rise to a slaty & ! latt] to a horny appe>ance 9 ! /one z se5 by ! unaid$ eye4 ,! col\r v>ies f grey to leaf- & d>k-gre51 ! t9t deep5+ z ! relative am\nt ( iron 9 ! composition increases1 & br[n t9ts result f ! oxidation ( ! iron along cracks 9 ! /one4 ,! h>dness is #f on ,mohs's scale2 nephrite is !re=e ab\t z h>d z ord9>y glass & s(t] ?an qu>tz4 ,:5 poli%$1 x always acquires a greasy lu/re4 ,! specific gravity ranges f #bi to #ca4 ,! lea/ & greate/ ( ! pr9cipal refractive indices are #afjf & #afcb respectively1 ! d\ble refraction be+ biaxial & negative2 ! col\r$ fibres also display di*roism4 ,all ^! diff]5tial effects are1 h[ev]1 mask$ 9 ! /one because ( ! irregul>ity ( ! aggregation4 ,nephrite is fusible be=e ! bl[pipe1 b only ) difficulty4 ,its "n is d]iv$ f ! ,greek ^w 1 kidney1 ! allusion be+ ! same z = jade4 ,_m ( ! prehi/oric implem5ts f\nd 9 ,mexico & 9 ! ,swiss ,lake ,habitations are compos$ ( nephrite1 b x is unc]ta9 :]e ! m9]al 0 obta9$4 ,mu* ( ! mat]ial us$ by ! ,*9ese at ! pres5t "t comes f spots ne> ! s\!rn b\nd>y ( ,ea/]n ,turke/an1 especially 9 ! valleys ( ! riv]s ,k>aka% & ,y>k& 9 ! ,kw5 ,lun range ( m\nta9s2 x is also f\nd f>!r nor? at ! riv] ,ka%g>4 ,x occurs 9 v>i\s prov9ces ( ,*9a1 namely1 ,%5si1 ,kwei ,*au1 ,kwang ,tung1 ,yunnan1 & ,man*uria4 ,gigantic wat]worn b\ld]s h be5 f\nd 9 ! ,gov]nm5t ( ,irkutsk1 ne> ,lake ,baikal1 9 ea/]n ,sib]ia1 ! fir/ discov]y be+ made 9 ! b$ ( ! ,onot /ream by ! explor] & prospector ,j4 ,p4 ,alib]t1 9 #ahej4 ,a l>ge b\ld] ( ?is k9d1 weigh+ ov] half a ton 7#aaef lb41 or #ebde kg471 is exhibit$ 9 ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory74 ,an enorm\s mass1 weigh+ ov] #b tons 7#dgah lb41 or #badj kg471 0 discov]$ at ,jordansmhl1 ,silesia1 by ,dr4 ,g4 ,f4 ,kunz1 & is n[ 9 ! magnific5t collection ( jade =m$ by ,mr4 ,heb] ,r4 ,bi%op4 ,beautiful gre5/one occurs 9 ,new ,zeal&1 p>ticul>ly 9 ! ,middle ,isl&4 ,! ,maoris h long us$ x = v>i\s useful & ornam5tal purposes1 ! mo/ common be+ indicat$ by _! g5]al "n = ! species1 punamu1 axe-/one2 kawakawa is ! ord9>y gre5 v>iety1 a f9e section ( :i* is %[n on ! wall ( ! ,m9]al ,gall]y ( ! ,briti% ,museum 7,natural ,hi/ory71 :ile inanga1 a grey v>iety1 & kahurangi1 a pale-gre5 & transluc5t v>iety1 are r>e & highly priz$4 ,jadeite 7,plate ,,xxix1 ,fig4 #ah7 is by f> ! r>] ( ! two jades1 & is ! *oice/ gem ) ! ,*9ese4 ,9 composition x is a silicate ( sodium & alum9ium ) ! =mula ,na,al7,si,o#c7b1 correspond+ to ! li?ium m9]al spodum5e 7p4 #bfe74 ,x has ! same t\ghness & greasy lu/re z nephrite1 b is h>d]1 be+ repres5t$ by ! symbol #g on ,mohs's scale1 & ?us only slightly1 if at all1 s(t] ?an qu>tz4 ,! o!r *>act]s are also high]2 ! specific gravity is ab\t #ccd1 & ! lea/ & greate/ ( ! pr9cipal refractive indices are #aff & #afh1 ! d\ble refraction be+ biaxial & negative4 ,! col\r v>ies f :ite to almo/ an em]ald gre51 ! latt] be+ especially priz$1 & (t5 ! gre5 col\r runs 9 /reaks ?r\gh ! :ite4 ,jadeite fuses readily be=e ! bl[pipe to blebby glass1 m easily ?an is ! case ) nephrite4 ,! f9e/ jadeite comes f ! ,mogaung di/rict 9 ,upp] ,burma1 :]e x is f\nd 9 b\ld]s & also ) albite 9 dykes 9 a d>k-gre5 s]p5t9e4 ,! export trade to ,*9a1 :i* absorbs practically ! :ole ( ! output1 is exce$+ly valuable1 & realizes ne>ly z mu* z ! produce ( ! ruby m9es4 ,jadeite is also f\nd 9 ! ,%5si & ,yunnan prov9ces ( ,*9a1 & 9 ,tibet4 ,a few words may be said ab\t ! o!r jade-l m9]als4 ,saussurite1 :i* is nam$ aft] ,h4 ,b4 de ,saussure1 has result$ f ! decomposition ( a felsp>1 & is ne>ly ak9 to ! m9]al zoisite4 ,x has ! cu/om>y t\ghness ( /ructure1 & is gre5i% grey to :ite 9 col\r4 ,its specific gravity is ab\t #cb1 & h>dness #f to #g on ,mohs's scale4 ,x occurs ne> ,lake ,g5eva4 ,b[5ite is a gre5 s]p5t9e 7p4 #bhi7 :i* is f\nd at ,smi?field1 ,rhode ,isl&1 ,u4,s4,a41 & 9 ,new ,zeal& & ,afghani/an4 ,cali=nite & plasma are compact v>ieties ( idocrase 7p4 #bge7 & *alc$ony 7p4 #bdg7 respectively4 ,v]dite is a /one ( ri* gre5 col\r :i* is f\nd 9 ! =m ( l>ge b\ld]s 9 ! ,nor? ,kaap ,riv]1 ,s\? ,africa2 x is compos$ ( gre5 mica 7fu*site7 & "s clayey matt]4 ,jade has ( rec5t ye>s be5 imitat$ 9 glass1 b ! latt] is recognizable by its vitre\s lu/re & inf]ior h>dness1 & soon] or lat] by its frangibility4 ,,*apt] ,,xxxiv ,,spodum5e1 ,,iolite1 ,,b5itoite ,,spodum5e 7,kunzite1 ,hidd5ite7 ,till a few ye>s ago sc>cely kn[n outside ! ranks ( m9]alogi/s1 spodum5e sudd5ly leap$ into notice 9 #aijc ^u ! discov]y ( ! lovely lilac-col\r$ /ones 7,plate ,,xxix1 ,fig4 #aj7 at ,pala1 ,san ,diego ,c\nty1 ,cali=nia2 !y %ortly aft]w>ds receiv$ ! "n kunzite aft] ! well-kn[n exp]t 9 gems1 ,dr4 ,g4 ,f4 ,kunz4 ,! /ones 7 f\nd "h 9 a pegmatite dyke1 & 7 ( all %ades1 rang+ f pale p9k to deep lilac1 & at times z mu* z #aej c>ats 9 weight4 ,pal] kunzite occurs ) b]yl & t\rmal9e at ,coahuila ,m\nta9 9 ,riv]side ,c\nty1 ,cali=nia1 & col\rless /ones h rec5tly come to light 9 ,madagasc>4 ,kunzite is rem>kable = its wond]ful di*roism2 ! beautiful violet t9t t spr+s out 9 "o direction comes ) great] surprise because ( ! un9t]e/+ yell[i% t9ts 9 o!r directions4 ,unlike spodum5e 9 g5]al1 kunzite is phosphoresc5t "u ! influ5ce ( radium4 ,! em]ald-gre5 v>iety 7,plate ,,xxix1 ,fig4 #aa71 nam$ hidd5ite aft] ,mr4 ,w4 ,e4 ,hidd51 :o discov]$ 9 #ahha ! only kn[n occurr5ce1 9 ,alex&] ,c\nty1 ,nor? ,c>ol9a1 w\ld no d\bt h become popul> _h ! supply ( mat]ial n be5 s v limit$2 few /ones 7 f\nd1 & ! v>iety has nev] come to light else:]e4 ,! col\r is suppos$ to be due to *romic acid4 ,hidd5ite be+ also di*roic1 ! t9t v>ies ) ! direction4 ,spodum5e is ord9>ily r a pale yell[i% 9 hue1 &1 z its "n 7:i* is d]iv$ f 1 a%-col\r$7 sugge/s1 is n v attractive4 ,cle>1 lemon-yell[ /ones 7,plate ,,xxix1 ,fig4 #i7 are f\nd 9 ,brazil & ,madagasc>4 ,! species is int]e/+ sci5tifically because x conta9s ! r>e elem5t li?ium2 x is a silicate ( alum9ium & li?ium1 correspond+ to ! =mula ,li,al7,si,o#c7b4 ,! d\ble refraction is biaxial 9 "* & positive 9 sign1 ! lea/ & greate/ ( ! refractive indices be+ #affj & #afge2 ! specific gravity is #cahe1 & h>dness #f to #g on ,mohs's scale4 ,spodum5e has an easy cleavage1 & ! cut /ones call !re=e = c>eful h&l+1 le/ !y be flaw$ or fractur$4 ,two facet$ /ones1 a beautiful kunzite & a f9e hidd5ite1 weigh+ #fj & #b c>ats respectively1 are exhibit$ 9 ! ,briti% ,museum 7,natural ,hi/ory74 ,,iolite ,kn[n also by v>i\s o!r names--cordi]ite1 di*roite1 & wat]-sapphire 7saphire d'eau7--?is species owes its int]e/ to ! rem>kable di*roism *>act]iz+ x1 ! pr9cipal col\rs--smoky-blue & yell[i% :ite--be+ 9 su* contra/ z to be obvi\s to ! unaid$ eye4 ,! /ones t are usually work$ h intr9sically a smoky-blue col\r1 & are f\nd 9 wat]worn masses 9 ! riv]-gravels ( ,ceylon1 :5ce is ! orig9 ( ! "n wat]-sapphire4 ,iolite1 f 1 violet1 & 1 /one1 ref]s to ! col\r2 cordi]ite is nam$ aft] ,cordi]1 a ,fr5* geologi/1 :o fir/ /udi$ ! cry/allography ( ! species2 & di*roite1 ( c\rse1 alludes to ! mo/ prom95t "* ( ! species4 ,iolite is a silicate ( alum9ium & ( magnesium & iron correspond+ to ! =mula ,h#b7,mg1,fe7#d;,al#h,si#aj,o#cg4 ,! d\ble refraction is small 9 am\nt1 biaxial 9 "*1 & negative 9 sign1 ! lea/ & greate/ ( ! refractive indices be+ #aedc & #aeea2 ! specific gravity is #bfc1 & h>dness #g on ,mohs's scale4 ,iolite1 if us$1 is work$ & poli%$2 x is seldom facet$4 ,a l>ge work$ piece1 weigh+ #agg grams1 :i* 0 =m]ly 9 ! ,hawk9s ,collection1 is exhibit$ 9 ! ,briti% ,museum 7,natural ,hi/ory74 ,,b5itoite ,! babe among gem-/ones1 b5itoite fir/ saw ! light ( day a few ye>s ago1 e>ly 9 #aijg4 ,x occurs ) ! r>e m9]al neptunite1 :i* 0 previ\sly kn[n only f ,gre5l&1 9 n>r[ ve9s ( natrolite 9 ,diablo ,range ne> ! head-wat]s ( ! ,san ,b5ito ,riv]1 ,san ,b5ito ,c\nty1 ,cali=nia4 ,despite c>eful se>* ! species has n be5 f\nd except )9 ! orig9al re/rict$ area4 ,to sci5ce x is int]e/+ bo? because ( its composition1 a silico-titanate ( b>ium1 correspond+ to ! =mula ,ba,ti,si#c,o#i1 & because its cry/als belong to a class ( cry/all9e symmetry :i* has hi!rto n be5 repres5t$ among m9]als4 ,! d\ble refraction is uniaxial1 & s9ce ! ord9>y index ( refraction is #ageg & ! extraord9>y #ahjd1 x is positive 9 sign & l>ge 9 am\nt1 namely1 #jjdg4 ,! /ones are *>act]iz$ by /rong di*roism1 ! col\r correspond+ to ! ord9>y ray be+ :ite1 & to ! extraord9>y gre5i% blue to indigo dep5d+ ^u ! t9t ( ! /one4 ,to obta9 ! be/ effect ! /one mu/ !re=e be cut ) ! table-facet p>allel to ! cry/allographic axis4 ,! specific gravity is #cfe1 & h>dness #f on ,mohs's scale4 ,:5 fir/ discov]$ ! species 0 suppos$ to be sapphire1 & _m /ones 7 cut & sold z su*4 ,x is1 h[ev]1 mu* s(t] ?an sapphire1 & is readily di/+ui%$ by its optical *>act]s1 s9ce x possesses great] d\ble refraction & ( diff]+ sign1 s t1 :5 te/$ ) ! refractomet]1 ! %ad[-edge correspond+ to ! l[] index ( refraction rema9s fix$ 9 ! case ( b5itoite1 :]eas ! contr>y happ5s ) sapphire4 ,b5itoite also1 unlike sapphire1 fuses easily to a transp>5t glass4 ,its blue col\r1 :i* is suppos$ to be due to a small am\nt ( free titanic acid pres5t1 appe>s to be /able4 ,sev]al /ones z l>ge z #a to #b c>ats 9 weight h be5 f\nd4 ,! l>ge/ ( all1 p]fectly flawless1 weighs j ov] #g c>ats1 & is rem>kable because x is ab\t ?ree times ! next l>ge/ 9 po9t ( weight2 x is ! prop]ty ( ,mr4 ,g4 ,eacret1 ( ,san ,francisco4 ,,*apt] ,,xxxv ,,euclase1 ,,ph5akite1 ,,b]yllonite ,,euclase ,?is species comes ne> b]yl 9 *emical composition1 be+ a silicate ( alum9ium & b]yllium correspond+ to ! =mula ,be7,al,o,h7,si,o#d1 & closely resembles aquam>9e 9 col\r & appe>ance :5 cut4 ,ow+ to ! r>ity ( ! m9]al good specim5s comm& high prices = museum collections1 & x is seldom wor? :ile cutt+ x = jewell]y4 ,x d]ives its "n f its easy cleavage1 easily1 & fracture4 ,! d\ble refraction is biaxial 9 "* & positive 9 sign1 ! lea/ & greate/ ( ! refractive indices be+ #afea & #afgj respectively2 ! specific gravity is #cjg1 & ! h>dness #g on ,mohs's scale4 ,! col\r is usually a sea-gre51 b sometimes blue4 ,euclase occurs ) topaz at ! ri* m9]al di/rict ( ,m9as ,novas1 ,m9as ,g]aes1 ,brazil1 & has also be5 f\nd 9 ! ,ural di/rict1 ,russia4 ,,ph5akite ,ano!r b]yllium m9]al1 ph5akite owes its "n to ! frequ5cy ) :i* x has be5 mi/ak5 = qu>tz1 be+ d]iv$ f 1 deceiv]4 ,! cle>1 col\rless cry/als1 some:at complex 9 =m1 h at times be5 cut1 b !y lack #8fire1' & despite _! brilliant lu/re meet ) little dem&4 ,! composition is a silicate ( b]yllium correspond+ to ! =mula ,be#b,si,o#d4 ,! d\ble refraction is uniaxial1 & s9ce ! ord9>y1 #afeb1 is less ?an ! extraord9>y index1 #affg1 x is positive 9 sign2 ! specific gravity is #bii1 & ! h>dness is almo/ equal to t ( topaz1 be+ ab\t #g to #h on ,mohs's scale4 ,f9e /ones h long be5 kn[n ne> ,ekat]9burg 9 ! ,ural ,m\nta9s1 & h rec5tly be5 discov]$ 9 ,brazil4 ,,b]yllonite ,z its "n sugge/s1 ?is m9]al also conta9s b]yllium1 be+ a soda phosphate correspond+ to ! =mula ,na,be,p,o#d4 ,cle>1 col\rless /ones1 :i* occur at ,/oneham1 ,ma9e1 ,u4,s4,a41 h be5 cut1 b ! lack ( #8fire1' ! easy cleavage1 & comp>ative s(tness1 ! symbol be+ #e on ,mohs's scale1 unfit x = use 9 jewell]y4 ,! d\ble refraction is biaxial 9 "* & negative 9 sign1 ! lea/ & ! greate/ ( ! refractive indices be+ #aeec & #aefe respectively4 ,,*apt] ,,xxxvi ,,en/atite1 ,,diopside1 ,,kyanite1 ,,&alusite1 ,,idocrase1 ,,epidote1 ,,sph5e1 ,,ax9ite1 ,,prehnite1 ,,apatite1 ,,dioptase ,,en/atite 7#8,gre5 ,g>net'7 ,! small gre5 /ones :i* accompany ! diamond 9 ,s\? ,africa h be5 cut & put on ! m>ket z #8gre5 g>net4' ,!y are1 h[ev]1 9 no way connect$ ) g>net1 b belong to a m9]al species call$ en/atite1 :i* is a silicate ( magnesium correspond+ to ! =mula ,mg,si,o#c2 ! gre5 col\r is due to a small am\nt ( f]r\s oxide :i* replaces magnesia4 ,! d\ble refraction is biaxial 9 "* & positive 9 sign1 ! lea/ & greate/ ( ! refractive indices be+ #affe & #afgd respectively2 ! specific gravity ranges f #caj to #cac1 & ! h>dness is only ab\t #e on ,mohs's scale4 ,! di*roism is p]ceptible1 ! tw9-col\rs be+ yell[i% & gre51 &1 z usual1 is m pron\nc$ ! deep] ! col\r ( ! /one4 ,!re is also a good cleavage 9 two diff]5t directions4 ,) increas+ p]c5tage am\nt ( iron en/atite passes into hyp]/h5e4 ,! col\r becomes a d>k br[ni% gre51 & an increase takes place 9 ! physical con/ants1 ! lea/ & greate/ ( ! refractive indices atta9+ to #afib & #agje respectively1 & ! specific gravity rang+ f #cd to #ce4 ,hyp]/h5e is nev] suffici5tly transp>5t = facet+1 b :5 spangl$ ) small scales ( brookite x is sometimes cut en cabo*on4 ,! "n en/atite is d]iv$ f 1 an oppon5t1 ref]r+ to ! infusibility ( ! m9]al be=e ! bl[pipe1 & hyp]/h5e comes f 1 v t\gh4 ,an alt]$ en/atite1 leek-gre5 9 col\r & ) ne>ly ! composition ( s]p5t9e 7p4 #bhi71 has be5 cut en cabo*on4 ,x has mu* l[] specific gravity1 only #bf1 & l[] h>dness1 #c to #d on ,mohs's scale4 ,x is nam$ ba/ite f ,ba/e 9 ! ,h>z ,m\nta9s1 :]e x 0 fir/ discov]$4 ,,diopside ,?is species1 :i* is also kn[n z malacolite & alalite1 provides /ones ( a leaf-gre5 col\r :i* h occasionally be5 cut4 ,x is a silicate ( calcium & magnesium correspond+ to ! =mula ,mg,ca7,si,o#c7b1 b usually conta9s 9 place ( magnesia "s f]r\s oxide1 to :i* x owes its col\r2 ) increase 9 ! p]c5tage am\nt ( iron ! col\r deep5s & ! physical con/ants *ange4 ,! d\ble refraction is l>ge 9 am\nt1 #jjbh1 biaxial 9 "*1 & positive 9 sign4 ,! lea/ & greate/ ( ! refractive indices correspond+ to ! /ones suitable = jewell]y range ab\t #afga & #afii respectively1 b !y may be z high z #agcb & #agej 9 ! two cases4 ,! specific gravity v>ies f #cbj to #cch1 & ! h>dness f #e to #f on ,mohs's scale4 ,di*roism is noticeable 9 deep-col\r$ /ones1 b is n v m>k$4 ,! "n diopside comes f 1 d\ble1 & 1 appe>ance1 9 allusion to ! effect result+ f ! d\ble refraction2 malacolite is d]iv$ f 1 s(t1 because ! m9]al is s(t] ?an ! felsp> associat$ ) x2 & alalite is nam$ aft] ! pr9cipal locality1 ,ala ,valley1 ,pi$mont1 ,italy4 ,,kyanite ,kyanite1 also kn[n z di/h5e1 is int]e/+ = two reasons4 ,its /ructure is s gra9$ 9 "* t ! h>dness v>ies 9 ! same /one f #e to #g on ,mohs's scale2 x c !re=e be scrat*$ by a knife 9 "s directions1 b n 9 o!rs 7p4 #gi74 ,x has ! same *emical composition z &alusite1 bo? be+ silicates ( alum9ium correspond+ to ! =mula ,al#b,si,o#e1 b possesses v diff]5t physical *>act]s1 a fact :i* %[s h[ l>ge a %>e ! molecul> gr\p+ has 9 det]m9+ ! aspect ( cry/alliz$ sub/ances4 ,x is biaxial ) small negative d\ble refraction1 ! lea/ & greate/ ( ! refractive indices be+ #agb & #agc respectively2 ! specific gravity is #cfa4 ,x occurs 9 sky-blue prismatic cry/als1 :iti% at ! edges1 9 s*i/ ne> ,/4 ,go?>d1 ,switz]l&4 ,x is seldom cut4 ,kyanite is d]iv$ f its col\r1 blue1 & di/h5e1 f its v>iable h>dness1 1 twice1 & 1 /rong4 ,,&alusite ,&alusite be>s no resemblance :atev] to kyanite1 al?\gh1 z has be5 /at$ above1 ! composition ( ! two species is ess5tially ! same4 ,x is usually light bottle-gre5 9 col\r1 & m r>ely br[n & r$di%4 ,its extreme di*roism is its mo/ rem>kable "*1 ! tw9 col\rs be+ olive-gre5 & r$4 ,! r$di% gleams t are reflect$ f ! int]ior are 9 %>p contra/ ) ! g5]al col\r ( ! /one1 & imp>t to x a weird effect 7,plate ,,xxix1 ,fig4 #ae74 ,cut /ones are (t5 confus$ ) t\rmal9es1 & c1 inde$1 only be di/+ui%$ f ! latt] ) c]ta9ty by not+ on ! refractomet] ! small] am\nt ( d\ble refraction & ! diff]5ce 9 its "*4 ,! lea/ & greate/ ( ! refractive indices are #afb & #afdc respectively1 & ! d\ble refraction1 #jjaa1 ab\t half t ( t\rmal9e1 is biaxial & negative2 ! specific gravity is #cah1 & h>dness #g on ,mohs's scale4 ,good /ones are f\nd at ,m9as ,novas1 ,m9as ,g]aes1 ,brazil1 & 9 ! gem-gravels ( ,ceylon4 ,x 0 fir/ kn[n f ! prov9ce ( ,&alusia1 ,spa91 :5ce is ! orig9 ( its "n4 ,,idocrase 7,vesuvianite1 ,cali=nite7 ,idocrase1 also kn[n z vesuvianite1 is occasionally f\nd 9 ! =m ( transp>5t1 leaf-gre51 & yell[i%-br[n /ones :i*1 :5 cut1 may be mi/ak5 = diopside & epidote respectively1 b are di/+ui%able f bo? by ! extreme smallness ( _! d\ble refraction4 ,cali=nite is a compact v>iety :i* has all ! appe>ances ( a jade2 its col\r is gre51 or ne>ly col\rless ) gre5 /reaks4 ,9 composition idocrase is a silicate ( alum9ium & calcium1 ! precise =mula ( :i* is unc]ta91 b may be-- 7,ca1,mn1,mg1,fe7#b7;,al1,fe77,,oh1,f7,s i#b,o#g4 ,! d\ble refraction1 :i* is uniaxial 9 "* & negative 9 sign1 may be less ?an #jjja1 & nev] exce$s #jjjf1 s t x is n easily detect$ ) ! refractomet]1 ev5 9 sodium light4 ,! refractive indices v>y enorm\sly 9 value1 f #agjb to #agbf = ! ord9>y1 & f #agjf to #agcb = ! extraord9>y ray4 ,! specific gravity v>ies f #cce to #cde1 & ! h>dness is ab\t #f on ,mohs's scale4 ,! "n idocrase1 f 1 =m1 & 1 mixture1 0 assign$ to ! species by ,hay1 b 8 reasons h little mean+ at ! pres5t day4 ,! o!r names are tak5 f ! localities :]e ! species & ! v>iety 7 fir/ discov]$4 ,bright1 gre5 cry/als come f ,russia1 & also f ,ala ,valley1 ,pi$mont1 & ,m\nt ,vesuvius1 ,italy4 ,cali=nite is f\nd 9 l>ge masses 9 ,siskiyon & ,fresno ,c\nties1 ,cali=nia4 ,,epidote 7,pi/acite7 ,epidote (t5 possesses a peculi> %ade ( yell[i% gre51 simil> to t ( ! pi/a*io-nut--h5ce ! orig9 ( its alt]native "n--:i* is unique among m9]als1 ?\gh sc>cely pleas+ en\gh to recomm5d x to g5]al ta/e4 ,its ready cleavage r5d]s x liable to flaws2 nev]!less1 x is occasionally facet$4 ,! "n epidote1 f 1 increase1 0 giv5 to x by ,hay1 b n on v precise cry/allographical gr\nds4 ,9 composition ?is species is a silicate ( calcium & alum9ium1 ) "s f]ric oxide 9 place ( alum9a1 correspond+ to ! complex =mula1 ,ca#b7;,al1,fe7#b7;,al1,fe7,,oh7,si,o#d7 c4 ,x occurs 9 monocl9ic1 prismatic cry/als ri*ly end[$ ) natural faces4 ,! col\r deep5s ) increase 9 ! p]c5tage am\nt ( iron1 & ! /ones become almo/ opaque4 ,! d\ble refraction is l>ge 9 am\nt1 #jjca1 biaxial 9 "*1 & negative 9 sign4 ,! di*roism is conspicu\s 9 transp>5t /ones1 ! tw9-t9ts correspond+ to ! pr9cipal optical directions be+ gre51 br[n1 & yell[4 ,! values ( ! lea/ & greate/ ( ! refractive indices giv5 by transp>5t /ones are #agce & #agff respectively2 ! specific gravity v>ies f #cbe to #cej1 & ! h>dness f #f to #g on ,mohs's scale4 ,transp>5t cry/als h come f ,knapp5w&1 ,unt]sulzba*tal1 ,salzburg1 ,au/ria2 ,trav]sella1 ,pi$mont1 ,italy2 & ,ar5dal1 ,n$5s1 ,norway4 ,magnific5t1 b v d>k1 cry/als 7 discov]$ ab\t t5 ye>s ago on ,pr9ce ( ,wales ,isl&1 ,alaska4 ,,sph5e 7,titanite7 ,! cle>1 gre51 yell[1 or br[ni% /ones provid$ by ?is species w\ld be welcom$ 9 jewell]y because ( _! brilliant & almo/ adamant9e lu/re1 b1 un=tunately1 !y are too s(t to )/& mu* we>1 ! h>dness be+ only #e on ,mohs's scale4 ,9 composition sph5e is a silico-titanate ( calcium correspond+ to ! =mula ,ca,ti,si,o#e1 & 9 ?is respect comes ne> ! rec5tly discov]$ gem-/one1 b5itoite4 ,! refractive indices lie outside ! range ( ! refractomet]1 ! values ( ! lea/ & ! greate/ ( ! refractive indices v>y+ f #ahhh & #aiag to #aiad & #bjec respectively4 ,x is to ?is high refraction t x owes its brilliant lu/re4 ,! d\ble refraction1 :i* is biaxial 9 "* & positive 9 sign1 is s l>ge t ! app>5t d\bl+ ( ! opposite edges ( a cut /one :5 view$ ?r\gh "o ( ! faces is obvi\s to ! unaid$ eye 7cf4 p4 #da74 ,cut /ones h additional int]e/ on acc\nt ( ! vivid di*roism display$1 ! tw9-t9ts1 col\rless1 yell[1 & r$di% yell[1 correspond+ to ! ?ree pr9cipal optical directions1 be+ 9 /rong contra/4 ,! specific gravity ranges f #cce to #cde4 ,! negative te/ ) ! refractomet] 7cf p4 #bf71 ! s(tness1 & ! l>ge am\nt ( d\ble refraction suffice to di/+ui% ?is species f gem-/ones ( simil> appe>ance4 ,! "n sph5e1 f 1 w$ge1 alludes to ! %ape ( ! natural cry/als4 ,! alt]native "n is obvi\sly due to ! fact t ! species conta9s titanium4 ,good /ones h come f ! ,/4 ,go?>d di/rict1 ,switz]l&4 ,,ax9ite ,call$ ax9ite f ! %ape ( its cry/als--1 axe--?is species supplies small1 cle>1 clove-br[n1 honey-yell[1 & violet /ones :i* c be cut = ^? :o c>e = a /one out ( ! ord9>y4 ,! composition is a boro-silicate ( alum9ium & calcium1 ) v>y+ am\nts ( iron & manganese1 correspond+ to ! =mula 7,ca1,fe7#c;,al#b7;,b4,,oh7,si#d,o#ae4 ,ax9ite is int]e/+ on acc\nt ( its /rong di*roism1 ! tw9-t9ts correspond+ to ! pr9cipal optical directions be+ violet1 br[n1 & gre54 ,! d\ble refraction is biaxial 9 "* & negative 9 sign1 ! lea/ & greate/ ( ! refractive indices be+ #afgd & #afhd2 ! specific gravity is #cbh1 & h>dness ab\t #f to #g1 or r "u t ( qu>tz4 ,! be/ examples h be5 f\nd at ,/4 ,cri/ophe1 ,b\rg d',oisans1 9 ! ,dauph91 ,france4 ,violet ax9ite is a novelty t has come )9 rec5t ye>s f ,roseb]y1 ,montagu ,c\nty1 ,tasmania4 ,,prehnite ,?is species1 :i* is nam$ aft] its discov]]1 ,colonel ,prehn1 is f\nd 9 nodul>1 yell[ & oil-gre5 /ones1 ( :i* ! latt] h v occasionally be5 cut4 ,x is a little s(t1 ! h>dness be+ only #f on ,mohs's scale4 ,! d\ble refraction is l>ge 9 am\nt1 #jjcc1 biaxial 9 "*1 & positive 9 sign1 ! lea/ & ! greate/ ( ! refractive indices be+ #afaf & #afdi respectively2 ! specific gravity v>ies f #bha to #bie4 ,9 composition prehnite is a silicate ( alum9ium & calcium correspond+ to ! =mula ,h#b;,ca#b;,al#b7,si,o#d7c4 ,! be/ mat]ial has be5 f\nd at ,/4 ,cri/ophe1 ,b\rg d',oisans1 ,dauph91 ,france4 ,,apatite ,?is int]e/+ m9]al is f\nd occasionally 9 attractive gre51 blue1 or violet /ones1 b is un=tunately too s(t = ext5sive use 9 jewell]y1 ! h>dness be+ only #e on ,mohs's scale4 ,9 composition x is a fluo-*loro-phosphate ( calcium1 correspond+ to ! =mula ,ca#d;,ca7,f1,cl77,,po#d7c4 ,:5 pure1 x is devoid ( col\r1 ! t9ts be+ due to ! pres5ce ( small am\nts ( t9ctorial ag5ts4 ,! d\ble refraction is uniaxial 9 "* & negative 9 sign1 ! ord9>y index be+ #afdb & ! extraord9>y #afdf2 ! specific gravity v>ies f #cag to #cbc4 ,! di*roism is usually feeble1 b sometimes is /rong2 = in/ance1 9 ! /ones f ! ,burma ruby m9es 7yell[1 blue-gre574 ,a cut /one might be mi/ak5 = t\rmal9e1 b is di/+ui%$ by its s(tness1 or1 :5 te/$ on ! refractomet]1 by its inf]ior d\ble refraction4 ,x receiv$ its "n f 1 deceive1 because x 0 wrongly assign$ to at lea/ half a doz5 diff]5t species 9 e>ly days4 ,moroxite is a "n sometimes giv5 to blue-gre5 apatite4 ,beautiful violet /ones are f\nd at ,ehr5fri$]sdorf1 ,saxony2 ,s*lagg5wald1 ,bohemia2 & ,m\nt ,apatite1 ,auburn1 ,&roscogg9 ,c\nty1 ,ma9e1 ,u4,s4,a42 & blue /ones come f ,ceylon4 ,,dioptase ,?\gh ( a pretty1 em]ald-gre5 col\r1 dioptase has nev] be5 f\nd 9 l>ge en\gh cry/als = gem purposes1 & x is1 moreov]1 r s(t1 ! h>dness be+ only #e on ,mohs's scale1 & has an easy cleavage4 ,9 composition x is a hydr\s silicate ( copp] correspond+ to ! =mula ,cu,h#b,si,o#d4 ,! d\ble refraction1 :i* is l>ge 9 am\nt1 is uniaxial 9 "*1 & positive 9 sign1 ! ord9>y refractive index be+ #affg & ! extraord9>y #agbc4 ,its col\r & s(tness di/+ui% x f p]idot or diopside1 :i* h ab\t ! same refractivity4 ,! "n 0 assign$ to ! species by ,hay1 f 1 ?r\gh1 & 1 see1 because ! cleavage directions 7 di/+ui%able by look+ ?r\gh ! /one4 ,dioptase has be5 f\nd ne> ,altyn-,tbe 9 ! ,kirghese ,/eppes1 at ,rezbnya 9 ,hung>y1 & ,copiapo 9 ,*ili1 & at ! m9e ,m9d\li1 ne> ,comba1 9 ! ,fr5* ,congo4 ,,*apt] ,,xxxvii ,,cassit]ite1 ,,anatase1 ,,pyrites1 ,,hematite ,,cassit]ite ,?\gh usually opaque1 ?is oxide ( t91 correspond+ to ! =mula ,sn,o#b1 has occasionally1 b v r>ely1 be5 f\nd 9 small1 transp>5t1 yell[ & r$di% /ones suitable = cutt+4 ,! lu/re is adamant9e4 ,! refraction is uniaxial 9 "* & positive 9 sign1 ! ord9>y index be+ #aiig & extraord9>y #bjic4 ,! specific gravity is high1 rang+ f #fh to #ga4 ,! h>dness is on ! :ole less ?an t ( qu>tz1 be+ ab\t #f to #g on ,mohs's scale4 ,,anatase ,?is m9]al1 :i* is "o ( ! ?ree cry/alliz$ =ms ( titanium oxide1 ,ti,o#b1 occurs (t5 9 small1 br[n1 transp>5t /ones :i* occasionally f9d _! way into ! m>ket4 ,! lu/re is adamant9e4 ,! refraction is uniaxial 9 "* & negative 9 sign1 ! extraord9>y index be+ #bdic & ord9>y #beed4 ,! specific gravity v>ies f #chb to #cie1 & ! h>dness is ab\t #e to #f on ,mohs's scale4 ,,pyrites1 ,,hematite ,^! two metallic m9]als 7 employ$ 9 anci5t jewell]y4 ,! =m]1 sulphide ( iron1 ,fe,s#b1 is brass-yell[ 9 col\r1 & has a specific gravity #eb1 & h>dness #f on ,mohs's scale4 ,x is f\nd1 :5 fre%1 9 brilliant cubes4 ,! latt]1 oxide ( iron1 ,fe#b,o#c1 has a black metallic lu/re1 b1 :5 p[d]$1 is r$ 9 col\r--a mode ( di/+ui%+ x f o!r m9]als ( simil> appe>ance4 ,its specific gravity is #ec1 & h>dness #f on ,mohs's scale4 ,9 mod]n times x has be5 cut 9 sph]ical =m to imitate black pe>ls1 b c easily be recogniz$ by its great] d5sity & h>dness4 ,hematite is us$ = signet /ones1 (t5 ) an intaglio engrav+4 ,,*apt] ,,xxxviii ,,obsidian1 ,,moldavite ,two =ms ( natural glass h be5 employ$ = ornam5tal purposes4 ,obsidian results f ! solidification )\t cry/allization ( lava1 & corresponds 9 composition to a granite4 ,! /ructure is seldom cle> & transp>5t1 & usually conta9s inclusions or /reaks4 ,! col\r is 9 ! mass jet-black1 b smoky 9 ?9 fragm5ts1 & occasionally gre5i%4 ,its prop]ty ( break+ ) a ke5 cutt+ edge1 9 ! same way z ord9>y glass1 r5d]$ x ( extreme utility to primitive man1 :o 0 ignorant ( ! artificial sub/ance4 ,! refraction is1 ( c\rse1 s+le1 & ! refractive index approximates to #aej4 ,! specific gravity v>ies f #bc to #be4 ,! h>dness is #e on ,mohs's scale1 ! same z ord9>y glass4 ,obsidian is obta9$ :]ev] !re has be5 volcanic activity4 ,va/ m9es ( great antiquity exi/ 9 ! ,/ate ( ,hidalgo1 ,mexico4 ,moldavite1 :i* diff]s 9 no respect f ord9>y gre5 bottle-glass1 is ( int]e/ on acc\nt ( its problematical orig94 ,its occurr5ce 9 v>i\s p>ts ( ,bohemia & ,moravia _c be expla9$ z ! result ( volcanic ag5cy4 ,x may possibly be ! product ( old & =gott5 glass factories :i* at "o "t exi/$ on ! site4 ,ev5 meteorites h be5 sugge/$ z ! s\rce4 ,! physical *>act]s are ! same z ^? ( ord9>y glass3 refraction s+le1 index #aea2 specific gravity #bej & h>dness #e on ,mohs's scale4 ,moldavite also passes "u ! names ( bottle-/one1 or wat]-*rysolite4 ,a natural glass ( ! same "* has be5 f\nd 9 wat]-worn fragm5ts 9 ,ceylon1 & has be5 sold z p]idot1 :i* x resembles 9 col\r1 b is readily di/+ui%$ f x by its v diff]5t physical prop]ties4 ,,"p ,,ii--,,section ,c ,,ornam5tal ,,/ones ,,*apt] ,,xxxix ,,fluor1 ,,lapis ,,lazuli1 ,,sodalite1 ,,violane1 ,,rhodonite1 ,,azurite1 ,,mala*ite1 ,,?ulite1 ,,m>ble1 ,,apophyllite1 ,,*rysocolla1 ,,/eatite ,,or ,,soap/one1 ,,me]s*aum1 ,,s]p5t9e ,space w n p]mit ( m ?an a few words conc]n+ ! m prom95t ( ! num]\s m9]al species :i* are employ$ = ornam5tal purposes 9 articles ( virtu or 9 ar*itecture1 b :i* = v>i\s reasons _c take rank z gem-/ones4 ,fluor1 a beautiful m9]al :i* is f\nd 9 its greate/ p]fection 9 ,engl&1 has enjoy$ well-des]v$ popul>ity :5 work$ into vases or o!r articles4 ,! f9e/ mat]ial1 deep purple 9 col\r1 kn[n z #8,blue ,john1' came f ,d]by%ire1 b ! supply is n[ exhau/$4 ,! cry/alliz$ examples1 f ,durham1 ,devon%ire1 & ,cornwall1 =m "s ( ! mo/ attractive ( museum specim5s4 ,! cry/als take ! %ape ( cubes1 (t5 tw9n$1 & h an easy octah$ral cleavage4 ,! refraction is s+le1 ! index be+ #adcc4 ,fluor is not$ = its prop]ty ( appe>+ ( diff]+ col\r by reflect$ & transmitt$ light1 & ! ph5om5on is 9 consequ5ce kn[n z fluoresc5ce4 ,! specific gravity is #cah1 & ! h>dness #d on ,mohs's scale4 ,ow+ to its l[ refraction & s(tness1 fluor is n suitable = jewell]y4 ,cle> col\rless mat]ial is 9 dem& = p>ticul> l5ses ( microscope objectives4 ,! lovely blue /one kn[n z lapis lazuli has s9ce ! e>lie/ times be5 appli$ to all k9ds ( decorative purposes1 = mosaic & inlaid "w & z ! mat]ial = vases1 boxes1 & s on1 & 0 ! orig9al sapphire ( ! anci5ts4 ,:5 gr\nd to p[d] x furni%es a f9e blue pa9t1 b x has n[ be5 entirely sup]s$$ = ?is purpose by an artificial product4 ,al?\gh to ! eye s homog5e\s & uni=m 9 /ructure1 lapis lazuli has be5 %[n by microscopic exam9ation to be compos$ ( calcite col\r$ by ?ree blue m9]als 9 v>y+ proportions4 ,all ?ree belong to ! cubic class ( symmetry1 & are ma9ly soda alum9ium silicates 9 composition2 _! h>dness v>ies f #e to #f on ,mohs's scale4 ,lazurite1 ,na#d7,na,s#c4;,al7,al#b,si#c,o#ab1 has specific gravity v>y+ f #bch to #bde1 & h>dness ab\t #e to #e2 haynite1 7,na#b1;,ca7#b7,na,s,o#d1;,al7,al#b,si#c ,o#ab1 is ab\t ! same 9 specific gravity1 #bd to #be1 b slightly h>d]1 #e to #f2 :ile sodalite1 ,na#d7;,al,cl7,al#b,si#c,o#ab1 is ! lighte/ 9 d5sity1 #bad to #bcj1 ) h>dness #e to #f1 & has a refractive index #adhc4 ,by f> ! olde/ m9es are 9 ! ,badak%an di/rict ( ,afghani/an1 a few miles above ,firgamu 9 ! valley ( ! ,kok*a1 a bran* ( ! ,oxus1 :]e ruby & sp9el are f\nd4 ,x is also f\nd at ! s\!rn end ( ,lake ,baikal1 ,sib]ia1 & 9 ! ,*ilian ,&es4 ,sodalite occurs 9 beautiful blue masses at ,dungannon1 ,ha/+s ,c\nty1 ,ont>io1 ,canada1 & at ,lit*field1 ,ma9e1 ,u4,s4,a4 ,!y make excell5t poli%$ /ones4 ,violane1 a massive1 d>k violet-blue diopside f ,san ,m>cel1 ,pi$mont1 ,italy1 also makes a h&some poli%$ /one4 ,rhodonite1 silicate ( manganese1 ,mn,si,o#c1 possesses a f9e r$ col\r1 & makes an attractive /one :5 cut & poli%$4 ,x has v slight biaxial d\ble refraction1 ! refractivity be+ ab\t #agc2 ! specific gravity is #cf1 & h>dness #f4 ,x is f\nd 9 l>ge masses ne> ,ekat]9burg 9 ! ,ural ,m\nta9s1 & is qu>ri$ z an ornam5tal /one4 ,bo? ! copp] c>bonates1 azurite or *essylite1 & mala*ite1 make effective poli%$ /ones4 ,! latt] is also work$ into v>i\s ornam5tal objects2 x occurs 9 fibr\s masses1 ! gra9$ "* ( :i* look well 9 ! poli%$ section4 ,its col\r is a bright gre51 to :i* x owes its "n1 f 1 mall[s4 ,its composition is repres5t$ by ! =mula ,cu,c,o#c4;,cu7,,oh7#b1 & x is ! m /able =m1 s9ce azurite is frequ5tly f\nd alt]$ to x4 ,x has biaxial d\ble refraction1 & ! indices are ab\t #ahh2 ! specific gravity is #dja1 & h>dness ab\t #c to #d on ,mohs's scale4 ,x is f\nd 9 l>ge masses at ! copp] m9es ( ,nizhni ,tagilsk 9 ! ,ural ,m\nta9s1 :]e x is m9$ z an ornam5tal /one2 x also accompanies ! copp] ores 9 _m p>ts ( ! _w1 = in/ance ,cuba1 ,*ili1 & ,au/ralia4 ,azurite1 s call$ on acc\nt ( its beautiful blue col\r1 is r>]1 b1 unlike mala*ite1 is g5]ally 9 ! =m ( cry/als4 ,beautiful specim5s h come f ,*essy1 ne> ,lyons1 ,france1 & ,bisbee1 ,arizona1 ,u4,s4,a4 ,! composition corresponds to ! =mula #b;,cu,c,o#c1 ,cu7,,oh7#b4 ,! specific gravity is #chj1 & h>dness ab\t #c to #d4 ,*rysocolla occurs 9 blue & blui%-gre5 e>?y masses1 ) an enamel-l texture1 :i* 9 "s in/ances c be work$ & poli%$4 ,be+ ! result ( ! decomposition ( copp] ores1 x v>ies consid]ably 9 h>dness1 rang+ f #b to #d on ,mohs's scale4 ,its composition approa*es to ! =mula ,cu,si,o#c4b;,h#b,o1 b x inv>iably conta9s impurities4 ,x is v light1 ! d5sity be+ only ab\t #bb4 ,/eatite1 or soap/one1 is a massive foliat$ silicate ( magnesium correspond+ to ! =mula ,h#b,mg#c,si#d,o#ab1 :i* is "o ( ! s(te/ ( m9]al sub/ances1 repres5t+ ! degree #a on ,mohs's scale1 b 9 massive pieces is h>d] ow+ to ! int]mixture ( o!r sub/ances ) x4 ,x has a peculi> greasy feel+ to ! t\*1 due to its s(tness4 ,! specific gravity is ab\t #bge4 ,! ,*9ese c>ve images out ( ! yell[i% & br[ni% pieces4 ,me]s*aum1 a silicate ( magnesium correspond+ to ! =mula ,h#d,mg#b,si#c,o#aj1 is famili> to e smok] z a mat]ial = pipe-b[ls4 ,x is v light1 ! specific gravity be+ only #bj1 & s(t1 ! h>dness be+ ab\t #b to #b on ,mohs's scale4 ,:5 f\nd1 x is pure :ite 9 col\r1 & answ]s to its "n1 a ,g]man ^w signify+ sea-foam4 ,x comes f ,asia ,m9or4 ,s]p5t9e has be5 l>gely us$ = decorative purposes1 z well z = cameos & intaglios1 & =m$ mo/ ( ! fam\s #8v]de antique4' ,be+ ! result ( ! decomposition ( o!r silicates x v>ies enorm\sly 9 appe>ance & *>act]s1 b ! mo/ attractive /ones are a ri* oil-gre5 9 col\r & resemble jade4 ,! composition approximates to ! =mula ,h#d,mg#c,si#b,o#i1 b x inv>iably conta9s o!r elem5ts4 ,! h>dness v>ies f #b to #d on ,mohs's scale1 accord+ to ! m9]als conta9$ 9 ! /one2 ! specific gravity is ab\t #bfj & ! refractivity #aegj4 ,! beautiful rose-r$ /one1 ?ulite1 makes a h&some decorative /one4 ,x has ne>ly ! same composition z epidote 7p4 #bge71 & l x has /rong di*roism1 ! pr9cipal col\rs be+ yell[1 light rose1 & deep rose4 ,! col\r is due to manganese4 ,its refractive index is ab\t #agj1 specific gravity #cab1 & h>dness #f to #f on ,mohs's scale2 x possesses an easy cleavage4 ,f9e specim5s come f ,telem>k1 ,norway1 & x is !re=e call$ aft] ! old "n = ,norway1 ,?ule4 ,m>ble is a massive calcite1 c>bonate ( lime1 ) ! =mula ,ca,c,o#c4 ,:5 pure x is :ite1 b x is usually /reak$ ) o!r sub/ances :i* imp>t a pleas+ v>iety to its appe>ance4 ,x is always readily recogniz$ by ! imm$iate eff]vesc5ce set up :5 t\*$ ) a drop ( acid4 ,calcite is highly d\bly refractive 7cf4 p4 #dj71 ! extraord9>y index be+ #adhf1 & ord9>y #afeh1 a diff]5ce ( #jagb2 ! specific gravity is #bga1 & h>dness #c on ,mohs's scale4 ,luma*elle1 or fire-m>ble1 is a lime/one conta9+ %ells f :i* a brilliant1 fire-l *atoyancy is emitt$ :5 light is reflect$ at ! prop] angle4 ,x sometimes resembles opal-matrix1 b is easily di/+ui%$ by its l[] h>dness & by its eff]vesc5t action ) acid4 ,*oice specim5s come f ,bleib]g 9 ,c>9?ia1 & f ,a/rakhan4 ,apophyllite has n _m *>act]s to comm5d x1 be+ at ! be/ fa9tly p9ki% 9 col\r1 & always imp]fectly transp>5t4 ,x is a hydr\s silicate ( potassium & calcium ) ! complex =mula 7,h1,k7#b;,ca7,si,o#c7b4;,h#b,o4 ,its refractivity is ab\t #aece1 specific gravity #be1 & h>dness #d on ,mohs's scale2 x possesses an easy cleavage4 ,x occurs 9 ! =m ( tetragonal cry/als at ,&reasb]g 9 ! ,h>z ,m\nta9s1 & 9 ! ,syhadree ,m\nta9s1 ,bombay1 ,india4 ,,"p ,,ii--,,section ,d ,,organic ,,products ,,*apt] ,,xl ,,pe>l1 ,,coral1 ,,amb] ,al?\gh none ( ! sub/ances consid]$ 9 ?is *apt] come )9 ! /rict def9ition ( a /one1 s9ce !y are directly ! result ( liv+ ag5cy1 yet pe>l at lea/ _c be d5i$ ! title ( a gem4 ,bo? pe>l & coral conta9 calcium c>bonate 9 "o or o!r ( its cry/alliz$ =ms1 & bo? are ga!r$ f ! sea2 b o!rwise !y h no?+ 9 common4 ,amb] is ( vegetable orig91 & is a v diff]5t sub/ance4 ,,pe>l ,f t unrecord$ day :5 "s scantily clo!d savage seek+ = succul5t food op5$ an oy/] & f\nd to 8 a/oni%m5t )9 its %ell a delicate silv]y pellet t %imm]$ 9 ! light ( a tropical sun1 d[n to ! pres5t day1 )\t int]mission1 pe>l has held a place all its own 9 ! rank ( jewels4 ,?\gh x be lack+ 9 durability1 its beauty _c be disput$1 & l>ge examples1 p]fect 9 =m & lu/re1 are suffici5tly r>e to tax ! deepe/ purse4 ,! sub/ance compos+ ! pe>l is id5tical ) ! iridesc5t l9+--"m-o'-pe>l or nacre1 z x is t]m$--( ! %ell4 ,tortur$ by ! intrusion ( "s liv+ ?+1 a bor+ p>asite1 a worm1 or a small fi%1 or ( a gra9 ( s& or o!r inorganic sub/ance1 & )\t means to free itself1 ! mollusc p]=ce neutralizes ! irritant matt] by conv]t+ x into an object ( beauty t ev5tually f9ds its way into "s jewell]y cab9et4 ,built up 9 a haphaz>d mann] & n conf9$ by ! inexorable laws ( int]molecul> action1 a pe>l may assume any & e v>iety ( %ape f ! regul> to ! fanta/ic4 ,x may be truly sph]ical1 egg- or pe>-%ap$--pe>-drops or pe>-eyes1 z !y are t]m$--or x may be q irregul>--! s-call$ b>oque or b>rok pe>ls4 ,! fir/ is ! mo/ priz$1 b a well-%ap$ drop-pe>l is 9 great dem& = p5dants or e>-r+s4 ,! col\r is ord9>ily :ite1 or fa9tly t+$ yell[i% or blui%1 & some:at r>ely1 salmon-p9k1 r$di%1 or blacki% grey4 ,p]fect black pe>ls are valuable1 b n z co/ly z ! f9e/ ( ! :ite4 ,?\gh n transp>5t1 pe>l is to a v>y+ ext5t transluc5t1 & its *>act]i/ic lu/re--#8ori5t' 9 ! language ( jewell]y--is due to ! same k9d ( int]action ( light reflect$ f diff]5t lay]s t has be5 rem>k$ ^u 9 ! case ( opal & c]ta9 o!r /ones4 ,! transluc5cy v>ies 9 degree1 & "s jewell]s speak ( ! #8wat]' ( pe>ls j z 9 ! case ( diamonds4 ,if a pe>l be slic$ across ! middle & ! section be exam9$ "u ! microscope1 x w be se5 t ! /ructure consi/s ( conc5tric %ells & resembles t ( an onion4 ,^! %ells are alt]nately compos$ ( calcium c>bonate 9 its cry/alliz$ =m1 aragonite1 & ( a horny organic matt] kn[n z con*iol91 & !y evid5tly repres5t ! result ( int]mitt5t gr[?4 ,because ( _! composite "*1 pe>ls h a specific gravity rang+ f #bfe to #bfi-bhd-bhi 9 ! case ( p9k pe>ls--:i* is appreciably less ?an t ( aragonite1 #bid3 ! h>dness is ab\t ! same1 namely1 #c to #d on ,mohs's scale4 ,t ! arrangem5t ( ! m9]al lay]s is approximately p>allel is ev9c$ by ! di/9ctness ( ! %ad[-edges %[n on exam9ation ) ! refractomet]4 ,pe>ls require v c>eful h&l+1 bo? because !y are comp>atively s(t & !re=e apt to be scrat*$1 & because !y are *emically affect$ by acids1 & ev5 by ! p]spiration f ! sk94 ,acids attack only ! calcium c>bonate1 n ! organic matt]2 ! well-kn[n /ory !re=e ( ,cleopatra dissolv+ a valuable pe>l 9 v9eg>1 :i* is moreov]1 too weak an acid to effect ! solution quickly1 mu/ n be accept$ too lit]ally4 ,pe>ls are n cut l /ones1 & !re=e z soon z ! preci\s bloom has once gone1 no?+ c be done to revive x4 ,attempts are sometimes made 9 ! case ( valuable pe>ls to remove ! dull sk9 & lay b>e ano!r iridesc5t lay] und]nea?1 b ! op]ation is exce$+ly delicate4 ,ev5 ) ! be/ ( c>e pe>ls mu/ 9 process ( "t p]i% ow+ to ! decay ( ! organic con/itu5t4 ,pe>ls t h be5 discov]$ 9 anci5t tombs crumbl$ to du/ at a t\*1 & ^? =m]ly 9 anci5t r+s h vani%$ or only rema9 z a br[n p[d]1 :ile ! g>nets or o!r /ones set ) !m are little ! worse = ! c5turies t h pass$ by4 ,! l>ge/ kn[n pe>l 0 at "o "t 9 ! fam\s collection belong+ to ! bank]1 ,h5ry ,philip ,hope4 ,cyl9drical 9 =m1 ) a slight swell+ at "o end1 x measures #ej mm4 7#b in*es7 9 l5g?1 & #aae mm4 7#d in*es7 9 circumf]5ce ab\t ! ?ick]1 & #hc mm4 7#c in*es7 ab\t ! ?9n] end1 & weighs #ded c>ats4 ,ab\t ?ree-qu>t]s ( x is :ite 9 col\r ) a f9e #8ori5t1' & ! rema9d] is bronze 9 t9t4 ,x is valu$ at upw>ds ( #ab1jjj4 ,a l>ge pe>l1 #cjj c>ats 9 weight1 is 9 ! imp]ial cr[n ( ! ,emp]or ( ,au/ria1 & ano!r1 pe>-%ap$1 is 9 ! possession ( ! ,%ah ( ,p]sia4 ,a beautiful :ite ,india pe>l1 a p]fect sph]e 9 %ape1 & #bh c>ats 9 weight1 is 9 ! ,museum ( ,zosima 9 ,mosc[2 x is kn[n z #8,la ,pellegr9a4' ,! #8,great ,s\!rn ,cross1' :i* consi/s ( n9e l>ge pe>ls naturally jo9$ toge!r 9 ! %ape ( a cross1 0 discov]$ 9 an oy/] fi%$ up 9 #ahhf (f ! b$s ( ,we/]n ,au/ralia4 ,! collection ( jewels 9 ! fam\s ,gre5 ,vaults at ,dresd5 conta9s a numb] ( pe>ls ( curi\s %apes4 ,l>ge pe>ls are sold sep>ately1 :ile ! small pe>ls kn[n z #8se$' pe>ls come into ! m>ket bor$ & /rung on silk 9 #8bun*es4' ,! unit ( weight is ! pe>l gra91 :i* is a qu>t] ( a c>at1 & ! rate ( price dep5ds on ! squ>e ( ! weight 9 gra9s4 ,! rate p] unit or base v>ies f #f;d4 to #ejs4 accord+ to ! %ape & quality ( ! pe>l4 ,sph]ical pe>ls comm& ! be/ prices1 next ! pe>l-drops1 & la/ly ! buttons2 b :atev] ! %ape1 x is imp]ative t ! pe>l h #8ori5t1' )\t :i* x is valueless4 ,! *eap] grades ( pe>ls are sold by ! c>at4 ,illu/ration3 ,,plate ,,xxx ,,natives ,,drill+ ,,pe>ls ,= use 9 necklaces & p5dants pe>ls are bor$ ) a /eel drill1 & ?read$ ) silk1 an easy op]ation on acc\nt ( _! s(tness4 ,!y h>monize well ) diamonds4 ,small pe>ls are (t5 set z a frame to l>ge col\r$ /ones1 to :i* !y =m an admirable foil4 ,pe>ls set 9 r+s or any:]e :]e ! upp] half alone w\ld %[ are g5]ally sawn 9 halves2 #8button' pe>ls f9d an ext5sive use 9 mod]n r+s4 ,any mollusc1 :e!r ( ! bi-valve or ! uni-valve type1 :i* possesses a nacre\s %ell1 has ! p[] ( produc+ pe>ls1 b only two1 ! pe>l-oy/]1 ,meleagr9a m>g>itif]a1 & ! pe>l-mussel1 ,unio m>g>if]1 repay ! co/ ( sy/ematic fi%+4 ,! outside ( ! %ell is =m$ ( ! horny matt] call$ con*iol92 :ile ! inside is compos$ ( two coats1 ( :i* ! out] consi/s ( alt]nate lay]s ( con*iol9 & calcium c>bonate 9 its cry/alliz$ =m1 calcite1 & ! inn] ( ! same organic matt]1 b ) calcium c>bonate 9 its o!r cry/alliz$ =m1 aragonite4 ,! latt] coat =ms ! nacre\s l9+ kn[n z "m-o'-pe>l1 :i* is id5tical 9 consi/5cy ) pe>l1 b some:at m transp>5t4 ,! iridesc5ce ( "m-o'-pe>l is due n only to ! fact t x is compos$ ( a succession ( ?9 transluc5t lay]s1 b also to ! fact t ^! lay]s ov]lap l slates on a h\se1 & =m a s]ies ( f9e p>allel l9es on ! surface2 diffraction !re=e z well z int]f]5ce ( light takes place1 & a simil> diffraction ph5om5on is display$ ev5 by a ca/ ( ! inside ( ! %ell4 ,! animal has ! prop]ty ( secret+ calcium c>bonate1 :i* x absorbs f ! sea-wat]1 9 bo? its cry/alliz$ conditions z well z con*iol94 ,at ! out] rim x secretes con*iol91 fur!r 9 calcite1 & at ! v inside aragonite4 ,! %ape & appe>ance ( a pe>l !re=e dep5d on ! position 9 :i* ! intrud+ sub/ance is situat$ )9 ! %ell4 ,! mo/ p]fect pe>l has be5 9 int]mitt5t motion 9 ! int]ior ( ! mollusc1 & has receiv$ successive coats accord+ to ! position 9 :i* x happ5$ to be4 ,a p>asite t bores into ! %ell is wall$ up at ! po9t ( entrance1 & a w>t- or bli/]-pe>l results4 ,! ?9n] ! successive coats ! f9] ! lu/re4 ,pe>ls h ev5 be5 discov]$ emb$d$ 9 ! animal itself4 ,! numb] ( pe>ls f\nd 9 a %ell dep5ds on ! numb] ( times ! liv+ ho/ 0 compell$ to seal up "s irritant object1 & may v>y f "o up to ! eighty-sev5 :i* are said to h be5 f\nd 9 an ,indian oy/]4 ,t an oy/] ?us di/+ui%$ has n l$ a happy exi/5ce is te/ifi$ by ! di/ort$ %ape ( its %ell1 a clue t guides ! pe>l-fi%]s 9 _! se>*4 ,moreov]1 pe>l-oy/]s nev] h ?ick nacre\s %ells1 & on ! o!r h& molluscs ) f9e "m-o'-pe>l seldom conta9 pe>ls4 ,beautiful :ite & silv]y pe>ls are f\nd 9 a small oy/] t lives at a dep? ( #f to #ac fa?oms 7#aa-bd m47 9 ! ,gulf ( ,mana>1 (f ! coa/ ( ,ceylon4 ,ab\t sev5-eigh?s1 h[ev]1 ( ! pe>ls t come into ! m>ket are obta9$ f a l>g] oy/] :i* has its home on ! ,arabian coa/ ( ! ,p]sian ,gulf4 ,^! fam\s fi%]ies h be5 kn[n s9ce v e>ly times4 ,! pe>ls f\nd "h are m yell[i% ?an ^? f ,ceylon1 b are nev]!less ( excell5t quality4 ,! pe>l fi%]ies (f ! nor?-we/ coa/ ( ,we/]n ,au/ralia & (f ,v5ezuela are also n unimportant1 & f9e black pe>ls h be5 suppli$ by molluscs f ! ,gulf ( ,mexico4 ,illu/ration3 ,,plate ,,xxxi ,,metal ,,figures ,,( ,,buddha ,,ins]t$ ,,9 ,a ,,pe>l-,,oy/] ,illu/ration3 ,,plate ,,xxxii ,,fig4 #a ,,fig4 #b ,,sections ,,( ,,culture ,,pe>l ,,fig4 #a4 ,,9 ,,! ,,oy/]4 ,,fig4 #b4 ,,:5 ,,f9i%$4 ,a4 ,,pe>ly ,,deposit4 ,b4 ,,piece ,,( ,,"m-,o'-,,pe>l ,,ins]t$ ,,9 ,,! ,,oy/]4 ,c4 ,,out] ,,%ell ,,( ,,! ,,oy/]4 ,d4 ,,"m-,o'-,,pe>l ,,back ,,add$4 ,! ,*9ese h long made a practice ( introduc+ into ! %ell ( a pe>l-oy/] little t9 images ( ,buddha 9 ord] t !y may be coat$ ) ! nacre\s secretion4 ,! ,japanese h dur+ rec5t ye>s made q an indu/ry ( /imulat+ ! ef=ts ( ! mollusc by cem5t+ small pieces ( "m-o'-pe>l to ! int]ior surface ( ! %ell 7,plate ,,xxxii1 ,fig4 #a72 ^! #8culture' pe>ls1 z !y are t]m$1 are recognizable by exam9ation ( ! back4 ,ab\t a ye> has to elapse be=e a coat+ ( a t5? ( a millimetre is =m$1 & ano!r two ye>s mu/ pass be=e ! ?ickness is d\bl$4 ,aft] removal ! piece ( "m-o'-pe>l1 :i* is n[ coat$ ) sev]al nacre\s lay]s1 is cem5t$ to a piece ( ord9>y "m-o'-pe>l1 & ! l[] portion is gr\nd to ! usual symmetrical %ape 7,plate ,,xxxii1 ,fig4 #b74 ,bli/] pe>ls are (t5 simil>ly treat$4 ,9 bo? cases1 h[ev]1 ! #8ori5t' is defici5t 9 quality4 ,! f9e/ "m-o'-pe>l is suppli$ by a mollusc f\nd 9 ! sea ne> ! isl&s ly+ betwe5 ,borneo & ! ,philipp9es1 & f9e mat]ial is f\nd at ,%>k ,bay & (f ,?ursday ,isl&4 ,,coral ,coral ranks f> bel[ pe>l & meets ) b limit$ appreciation4 ,x is common en\gh 9 w>m seas1 b ! only k9d :i* f9ds its way into jewell]y is ! rose or r$-col\r$ coral--! noble coral1 ,corallium nobile or rubrum4 ,x consi/s ( ! axial skeleton ( ! coral polyp1 & is built up ( holl[ tubes fitt+ "o )9 ! o!r4 ,! composition is ma9ly calcium c>bonate ) a little magnesium c>bonate & a small am\nt ( organic matt]4 ,! =m] ( ! m9]al sub/ances is 9 ! =m ( calcite1 & ! cry/als are arrang$ 9 fibr\s =m radiat+ at "r angles to ! axis ( ! coral4 ,! specific gravity v>ies f #bf to #bg1 be+ slightly "u t ( calcite1 & ! h>dness is some:at great]1 be+ ab\t #c on ,mohs's scale4 ,! be/ r$ coral is f\nd 9 ! ,m$it]ranean ,sea (f ,algi]s & ,tunis 9 ,africa1 & ,sicily & ! ,calabrian ,coa/ ( ,italy4 ,! indu/ry ( %ap+ & fa%ion+ ! coral is c>ri$ on almo/ entirely 9 ,italy4 ,coral is usually cut into beads1 ei!r r\nd or egg-%ap$1 & us$ = necklaces1 ros>ies1 & bracelets4 ,! be/ quality fet*es f #bjs4 to #cjs4 p] c>at4 ,,amb] ,?is fossil res91 yell[ & br[ni%-yell[ 9 t9t1 f9ds an ext5sive use z ! mat]ial = m\?pieces ( pipes1 cig> & cig>ette-hold]s1 umbrella-h&les1 & s on1 & is ev5 locally cut = jewell]y1 al?\gh its extreme s(tness1 its h>dness be+ only #b on ,mohs's scale1 q unfits x = su* a purpose4 ,x is only slightly d5s] ?an wat]1 ! specific gravity be+ ab\t #aaj4 ,s9ce ! /ructure is amorph\s ! refraction is s+le1 ! index be+ ab\t #aedj4 ,amb]1 be+ a v bad conductor ( heat1 is p]ceptibly w>m to ! t\*4 ,its prop]ty ( becom+ electrifi$ by friction attract$ e>ly att5tion1 & f ! ,greek "n = x1 1 is d]iv$ our ^w electricity4 ,amb] is wa%$ up by ! sea (f ! coa/s ( ,sicily & ,prussia1 & ( ,norfolk & ,suffolk 9 ,engl&4 ,! f9e/ examples1 :i* are pick$ up (f ! %ore ( ,catania 9 ,sicily1 are di/+ui%$ by a f9e blui% fluoresc5ce1 resembl+ t se5 9 lubricat+ oil2 su* pieces comm& good prices4 ,a rec5t res91 pale yell[ 9 col\r1 kn[n z kauri-gum1 is f\nd 9 ,new ,zeal&1 :]e x is highly valu$4 ,,tables ,,table ,i ,*emical ,composition ( ,gem-,/ones 7a7 ,,elem5ts-- ,diamond ,c 7b7 ,,oxides-- ,corundum ,al#b,o#c ,qu>tz ,si,o#b ,*alc$ony ,si,o#b ,opal ,si,o#b4n,h#b,o 7c7 ,,alum9ates-- ,sp9el ,mg,al#b,o#d ,*rysob]yl ,be,al#b,o#d 7d7 ,,silicates-- ,ph5akite ,be#b,si,o#d ,dioptase ,h#b;,cu,si,o#d ,p]idot ,mg#b,si,o#d ,zircon ,zr,si,o#d ,en/atite ,mg,si,o#c ,diopside ,ca,mg7,si,o#c7b ,nephrite ,ca,mg#c7,si,o#c7d ,sph5e ,ca,ti,si,o#e ,b5itoite ,ba,ti,si#c,o#i ,&alusite ,al7,al,o7,si,o#d ,kyanite 7,al,o7#b,si,o#c ,topaz ,al7,f1,,oh7#b,si,o#d ,epidote ,ca#b7;,al1,fe7#b7;,al,o,h77,si,o#d7c ,euclase ,be7,al,o,h7,si,o#d ,prehnite ,h#b;,ca#b;,al#b7,si,o#d7c ,iolite ,h#b7,mg1,fe7#d;,al#h,si#aj,o#cg ,hessonite ,ca#c;,al#b7,si,o#d7c ,g>net ,pyrope ,mg#c;,al#b7,si,o#d7c ,alm&9e ,fe#c;,al#b7,si,o#d7c ,&radite ,ca#c;,fe#b7,si,o#d7c ,b]yl ,be#c;,al#b7,si,o#c7f ,spodum5e ,li,al7,si,o#c7b ,jadeite ,na,al7,si,o#c7b ,moon/one ,k,al,si#c,o#h ,t\rmal9e#ab,si,o#b4c;,b#b,o#c47i-x77,al 1,fe7#b,o#c4cx 7,fe1,mn1,ca1,mg1,k#b1,na#b1,li#b1;,h#b7 ,o4#c;,h#b,o ,ax9ite ,h,ca#c;,al#b;,b7,si,o#d7d ,idocrase 7,ca1,mn1,mg1,fe7#b7;,al1,fe77,,oh1,f7,s i#b,o#g 7e7 ,,phosphates-- ,b]yllonite ,na,be,p,o#d ,apatite ,ca#e7;,f1,cl77,,po#d7c ,turquoise ,cu,o,h4#f;,al7,,oh7#b4;,h#e47,,po#d7d ,,table ,,ii ,col\r ( ,gem-,/ones ,col\rless & ,:ite4--,diamond1 corundum 7:ite sapphire71 topaz1 qu>tz 7rock-cry/al71 zircon 7:5 #8fir$'71 moon/one2 r>ely b]yl1 t\rmal9e2 among ! less common species1 ph5akite1 spodum5e 7col\rless kunzite71 b]yllonite4 ,yell[4--,diamond1 topaz1 corundum 7yell[ sapphire71 qu>tz 7citr9e1 ,scot* or occid5tal topaz71 t\rmal9e1 zircon1 sph5e1 spodum5e1 b]yl4 ,p9k & ,lilac4--,corundum 7p9k sapphire71 sp9el 7balas-ruby71 t\rmal9e 7rubellite71 topaz 7usually :5 #8fir$'71 spodum5e 7kunzite71 b]yl 7morganite71 qu>tz 7rose-qu>tz74 ,r$4--,corundum 7ruby71 g>net 7pyrope1 alm&9e71 sp9el 7balas-ruby71 t\rmal9e 7rubellite71 zircon1 opal 7fire-opal74 ,gre54--,b]yl 7em]ald1 aquam>9e71 p]idot1 corundum1 t\rmal9e1 *rysob]yl 7includ+ alex&rite71 zircon1 g>net 7demantoid72 among less common species1 spodum5e 7hidd5ite71 euclase1 diopside1 idocrase1 epidote1 apatite1 obsidian2 r>ely diamond2 also semi-opaque1 turquoise1 jade4 ,blue4--,corundum 7sapphire71 sp9el1 topaz1 t\rmal9e1 zircon2 among ! less common species1 kyanite1 iolite1 b5itoite1 apatite2 r>ely diamond2 also semi-opaque1 turquoise1 lapis lazuli1 sodalite4 ,violet & ,purple4--,qu>tz 7ame?y/71 corundum 7ori5tal ame?y/71 sp9el 7alm&9e-sp9el71 g>net 7alm&9e71 spodum5e 7kunzite71 apatite4 ,br[n4--,diamond1 t\rmal9e1 qu>tz 7smoky-qu>tz72 among ! less common species1 &alusite1 ax9ite1 sph5e4 ,,table ,,iii ,refractive ,indices ( ,gem-,/ones#h ,opal #aded ,moon/one #aec #aed ,iolite #aedc #aeea ,qu>tz #aedd #aeec ,b]yllonite #aeec #aefe ,b]yl #aegh #aehe ,turquoise #afa #afe ,topaz #afah #afbg ,&alusite #afcb #afdc ,t\rmal9e #afbf #afea ,apatite #afdb #afdf ,ph5akite #afeb #affg ,euclase #afea #afgj ,spodum5e #affj #afge ,en/atite #affe #afgd ,p]idot #afei #afig ,ax9ite #afgd #afhd ,diopside #afhe #agje ,idocrase #agad #agai ,sp9el #agbf ,kyanite #agb #agc ,epidote #agce #agff ,g>net 7,hessonite7 #agde ,*rysob]yl #agdf #agec ,g>net 7,pyrope7 #agee ,b5itoite #ageg #ahjd ,corundum #agfa #aggj ,g>net 7,alm&9e7 #agij ,zircon 7a7 #ahae ,g>net 7,demantoid7 #ahhe ,sph5e #aija #aihe ,zircon 7b7 #aibg #aihj ,diamond #bdag ,,table ,,iv ,col\r-,disp]sion ( ,gem-,/ones#i ,moon/one #jab ,qu>tz #jac ,b]yl #jad ,topaz #jad ,*rysob]yl #jae ,t\rmal9e #jag ,spodum5e #jag ,corundum #jah ,p]idot #jbj ,sp9el #jbj ,g>net 7,alm&9e7 #jbd ,g>net 7,pyrope7 #jbg ,g>net 7,hessonite7 #jbh ,zircon #jch ,diamond #jdd ,sph5e #jea ,g>net 7,demantoid7 #jeg ,,table ,v ,"* ( ! ,refraction ( ,gem-,/ones 7a7 ,,s+le-- ,diamond1 sp9el1 g>net1 opal4 ,diamond & g>net frequ5tly display local d\ble refraction4 7b7 ,,uniaxial1 ,,positive-- ,qu>tz #jji ,ph5akite #jae ,b5itoite #jdg ,zircon 7b7 #jec ,qu>tz exhibits circul> pol>ization4 7c7 ,,uniaxial1 ,,negative-- ,apatite #jjd ,idocrase #jje ,b]yl #jjg ,corundum #jji ,t\rmal9e #jbe 7d7 ,,biaxial1 ,,positive-- ,*rysob]yl #jjg ,topaz #jji ,en/atite #jji ,spodum5e #jae ,euclase #jai ,diopside #jbj ,p]idot #jch ,sph5e #jhd 7e7 ,,biaxial1 ,,negative-- ,moon/one #jjf ,iolite #jjh ,ax9ite #jaj ,&alusite #jaa ,b]yllonite #jab ,kyanite #jaf ,epidote #jca ,,table ,,vi ,di*roism ( ,gem-,/ones 7a7 ,,/rong ,corundum1 t\rmal9e1 alex&rite1 spodum5e1 &alusite1 iolite1 epidote1 ax9ite4 7b7 ,,di/9ct ,em]ald1 topaz1 qu>tz1 p]idot1 *rysob]yl1 en/atite1 euclase1 idocrase1 kyanite1 sph5e1 apatite4 7c7 ,,weak ,b]yl1 diopside4 ,,table ,,vii ,specific ,gravities ( ,gem-,/ones ,opal #bae ,moon/one #beg ,iolite #bfc ,qu>tz #bff ,b]yl #bgd ,turquoise #bhb ,b]yllonite #bhd ,ph5akite #bii ,euclase #cjg ,t\rmal9e #caj ,en/atite #caj ,&alusite #cah ,spodum5e #cah ,apatite #cbj ,ax9ite #cbh ,diopside #cbi ,epidote #ccg ,p]idot #cdj ,idocrase #cdj ,sph5e #cdj ,diamond #ceb ,topaz #cec ,sp9el #cfj ,kyanite #cfa ,g>net 7,hessonite7 #cfa ,b5itoite #cfd ,*rysob]yl #cgc ,g>net 7,pyrope7 #cgh ,g>net 7,demantoid7 #chd ,corundum #djc ,g>net 7,alm&9e7 #dje ,zircon 7a7 #dbj ,zircon 7b7 #dfi ,,table ,,viii ,degrees ( ,h>dness ( ,gem-,/ones #e4 ,kyanite 7#e-g71 apatite1 lapis lazuli #e4 ,en/atite1 b]yllonite1 sph5e #f4 ,opal1 moon/one1 turquoise1 diopside #f4 ,spodum5e1 p]idot1 g>net 7demantoid71 b5itoite1 idocrase1 epidote1 ax9ite1 jade 7nephrite7 #g4 ,iolite1 qu>tz1 t\rmal9e1 jade 7jadeite7 #g4 ,g>net 7hessonite1 pyrope7 #g4 ,b]yl1 g>net 7alm&9e71 zircon1 ph5akite1 euclase1 &alusite #h4 ,topaz1 sp9el #h4 ,*rysob]yl #i4 ,corundum #aj4 ,diamond ,,table ,,ix4--,,data ,d5sities ( ,wat] & ,toluol at ,ord9>y ,temp]atures ---------------------------------------- --------- ,,temp]ature ,,wat] ,,toluol ---------------------------------------- --------- ,c5tigrade ,fahr5heit #ad #egb #jiiid #jhfig #ae #eij #jiiib #jhfhg #af #fjh #jiiij #jhfgg #ag #fbf #jiihh #jhffg #ah #fdd #jiihf #jhfeg #ai #ffb #jiihe #jhfdg #bj #fhj #jiihc #jhfcg #ba #fij #jiiha #jhfbg #bb #gaf #jiigi #jhfag #bc #gcd #jiigg #jhfjg ---------------------------------------- --------- #a ,engli% c>at #jbjec gram #a ,metric c>at #jbjjj 7"o-fif?7 gram #a oz4 ,av4 #bhce grams #a lb4 ,av4 #jdecf kilogram #a in* #bed millimetres #a foot #jcjdh metre #a y>d #jiadd metre #a mile #afjic kilometre ,,index ,absorption1 #ec1 #ei ,absorption spectra1 #ei ,a*roite1 #bbj1 #bba ,adul>ia1 #bee ,agate1 #bdg ,akb> ,%ah diamond1 #afc ,alalite1 #bgb ,albite1 #bed ,alex&rite1 #ed1 #fj1 #bcc ,sci5tific1 #abb ,alm&9e1 #fj1 #bad ,ori5tal1 #aab1 #agb sp9el1 #aab1 #bjd ,amazon-/one1 #bee ,amb]1 #hc1 #bih ,ame?y/1 #bci1 #bdb ,ori5tal1 #aaa1 #agb1 #bci ,anatase1 #bha ,&alusite1 #bgd ,&radite1 #baf ,anomal\s refraction1 #dg ,anor?ite1 #bed ,apatite1 #bgi ,apophyllite1 #bij ,aquam>9e1 #ahd1 #aic ,arizona-ruby1 #bac ,artificial /ones1 #abd ,a/]ia1 #ch1 #agg ,a/]ism1 #ch ,au/ralia /ones1 #aed1 #agd1 #ahb1 #aie1 #bac1 #baf1 #bbg1 #bcb1 #beb1 #bhh ,au/rian ,yell[ diamond1 #afe ,av5tur9e1 #bdj1 #bda ,axes1 ,cry/allographic1 #i ,optic1 #di ,ax9ite1 #bgh ,azure-qu>tz1 #bdd ,azurite1 #bhg ,balas-ruby1 #bjc ,b>nato1 ,b>nett1 #ade ,b>oque1 ,b>rok1 pe>ls1 #bib ,ba/ite1 #bgb ,b5itoite1 #bfg ,b]quem1 ,l\is de1 #ij1 #afa ,b]yl1 #ahd ,b]yllonite1 #bgj ,bezel facet1 #ib ,biaxial d\ble refraction1 #de1 #di1 #eg ,bisectrix1 #de1 #di ,black diamond1 #abi ,black lead1 #abi ,black opal1 #bdi1 #bej ,black ,pr9ce's ruby1 #bjf ,bli/]-pe>l1 #bif ,blood/one1 #bdg ,blue felsp>1 #bee ,blue gr\nd1 #adc1 #adg ,blue ,john1 #bhe ,bo>t1 #ajc1 #abi1 #acc ,bohemian g>net 7pyrope71 #bjg1 #bab ,bone turquoise1 #bei ,boodt1 ,a4 ,b4 de1 #acb1 #bac ,borgis1 ,hort5sio1 #afa ,borneo /ones1 #aed1 #agj ,bort1 v4 ,bo>t1 #ajc1 #abi1 #acc ,bottle-/one1 #bhd ,b\le1 #aah ,b[5ite1 #bfc ,braganza diamond1 #agj ,brazil /ones1 #ach1 #afe1 #aff1 #afi1 #aid et seq41 #bja1 #bae1 #bbc1 #bcf1 #bdc1 #bdd1 #bdh1 #bff1 #bfi1 #bgj1 #bgd ,brazilian em]ald1 #aaa1 #bbj1 #bba p]idot1 #bba sapphire1 #aaa1 #bba topaz1 #aaa1 #aig ,brilliant =m ( cutt+1 #ib ,brilliant1 ,sci5tific1 #abb ,bri/ol diamonds1 #bdc ,brut+1 #ajj ,burma /ones1 #agh1 #bje1 #bbc1 #bbg1 #bfc ,button-pe>l1 #bie ,byes1 ,bywat]s1 #acf1 #aej ,cabo*on =m ( cutt+1 #hh ,ca*olong1 #bea ,cairngorm1 #bci ,callaica1 calla9a1 callais1 #beh ,calcite1 #dj1 #bhi ,cali=nia /ones1 #aef1 #aie1 #bjb1 #bbd1 #bei1 #bfe1 #bfg1 #bge ,cali=nite1 #bfd1 #bge ,cape-ruby1 #bac ,c>at weight1 #gb1 #hd ,c>bon1 #abi ,c>bonado1 #abi ,c>borundum1 #aje ,c>buncle1 #hi1 #bae ,c>nelian1 #bdg ,cascalho1 #aci ,cassit]ite1 #bha ,cat's-eye 7*rysob]yl71 #ch1 #ij1 #bcc 7qu>tz71 #ci1 #ij1 #bdj 7t\rmal9e71 #ci1 #bai ,hung>ian1 #bdd ,ceylon /ones1 #aha1 #aie1 #bja1 #bje1 #bab1 #bae1 #baf1 #bbc1 #bcb1 #bcf1 #bcg1 #bdc1 #bdd1 #bee1 #bfg1 #bgd1 #bgi1 #bhd ,ceylonese p]idot 7t\rmal9e71 #bba ,ceylonite1 #bjd ,*alc$ony1 #bdf ,*atoyancy1 #ch ,*]t1 #bdg ,*essylite1 #bhg ,*rysob]yl1 #bcc ,*rysocolla1 #bhh ,*rysolite 7*rysob]yl71 #bcc 7p]idot71 #bbe ,*rysoprase1 #bdg ,*ur*1 ,sir ,ar?ur1 #fa1 #baa1 #bca ,c9namon-/one1 #baa ,citr9e1 #bci ,cleavage1 #hj1 #ajj1 #adi ,close goods1 #adi ,col5so diamond1 #aca ,col\r1 #ec ,col\r disp]sion1 #bj1 #ig ,con*iol91 #bic ,coral1 #bih ,cordi]ite1 #bff ,corni% diamonds1 #bdc ,corundum1 #agb ,crocidolite1 #ci1 #bdj ,crookes1 ,sir ,william1 #acb1 #aec ,cross facet1 #ic ,cry/al1 #f1 #g1 #h ,rock-1 #ig ,cubic sy/em1 #h ,culet facet1 #ic ,cull9an diamond1 #id1 #ajj1 #afh ,culture pe>ls1 #big ,cumb]l& diamond1 #afd ,cyanite 7,kyanite71 #gi1 #bgc ,cymophane1 #bcd ,d>ya-i-nor diamond1 #afb ,de ,be]s diamonds1 #afg ,demantoid1 #baf ,d5sity1 #fc ,deviation1 ,m9imum1 #cj ,diamond1 ,*>act]s (1 #abh cutt+1 #ij gauges1 #hf ,glazi]s'1 #ace m9+1 #adf ,occurr5ce (1 9-- ,borneo1 #aed ,brazil1 #aci ,g]man ,s\?-,we/ ,africa1 #aee ,india1 #ach ,new ,s\? ,wales1 #aed ,rhodesia1 #aee ,s\? ,africa1 #aci ,orig9 (1 #aea -po9t1 #ia -rose1 #ib -table1 #ia ,diamonds1 ,classification (1 #acf1 #adi ,hi/orical1 #aeg ,prices (1 #ace ,di*roism1 #ee ,di*roite1 #bff ,di*roscope1 #ee ,diffusion column1 #fe ,diopside1 #bgb ,dioptase1 #bhj ,disp]sion1 ,col\r1 #bj1 #bd1 #ig ,di/h5e1 #bgc ,dop1 #ajb ,d\ble refraction1 #bh1 #dj ,d\blet1 #abe ,dresd5 diamond1 #aga ,drop-/one1 #id ,duke ( ,devon%ire's em]ald1 #aia ,edw>des ruby1 #age ,electrical *>act]s1 #hb ,em]ald1 #hi1 #ahd ,brazilian1 #bbj1 #bba ,ev5+1 #bbe ,ori5tal1 #aaa1 #agb ,sci5tific1 #abb ,uralian1 #baf ,em]ald9e1 #bdg ,em]y1 #age ,engli% ,dresd5 diamond1 #aff ,en/atite1 #bga ,epidote1 #bge ,ess5ce d',ori5t1 #abf ,essonite 7,hessonite71 #baa ,euclase1 #bfi ,eugnie diamond1 #afd ,ev5+ em]ald1 #bbe ,excelsior diamond1 #afg ,ext9ction1 #de ,facet+ ma*9e1 #aje ,false topaz1 #bci ,felsp>1 #bed ,fire1 #bj1 #if ,fire-m>ble1 #bhi ,fire-opal1 #bea ,flats1 #aej ,fl*es d'am\r1 #bdj ,fl9t1 #bdg ,floors1 #adg ,fluor1 #bhe ,frmy1 ,e41 #aae ,g>net1 #bjg ,gre51 #bga ,gaud91 ,m4 ,a4 ,a41 #aae ,gauges1 ,diamond1 #hf ,girdle1 #ib ,glass1 #g1 #abd ,gnaga ,boh ruby1 #ahj ,goniomet]1 #cj ,gra91 ,pe>l1 #hf ,graphite1 #abi ,greas]1 #adi ,great ,mogul diamond1 #afa ,great ,s\!rn ,cross gr\p ( pe>ls1 #bid ,great ,table diamond1 #afb ,great ,:ite diamond1 #afg ,gre5 g>net1 #bga ,gre5/one1 #bfa ,grossul>1 #baa ,habit1 #ab ,h>dness1 #gh ,haynite1 #bhf ,heavy liquids1 #fd ,hematite1 #bhb ,hessonite1 #baa ,hexagonal sy/em1 #aj ,hidd5ite1 #bff ,hope cat's-eye1 #bcg *rysolite1 #bcg diamond1 #agj pe>l1 #bid sapphire1 #aba ,horn/one1 #bdg ,hung>ian cat's-eye1 #bdd ,hyac9?1 #baa1 #bbh ,hydrophane1 #bej ,hydro/atic weigh+1 #gb ,hyp]/h5e1 #bga ,icel&-sp>1 #dj1 #dd ,idocrase1 #bgd ,imitation /ones1 #abd ,imp]ial diamond1 #afg ,index ( refraction1 #af ,india /ones1 #acg1 #aha1 #aid1 #bae1 #bdc1 #bdd1 #bdh1 #bij ,indicators1 #fe ,indicolite1 #bba ,int]f]5ce ( light1 #ci1 #dh ,iolite1 #bff ,iris1 #bdj ,isle ( ,wight diamonds1 #bdc ,isomorph\s replacem5t1 #ac1 #ai ,jac9?1 #baa1 #bbh ,jade1 #bfj ,jadeite1 #bfb ,j>goon1 #bbh ,jasp]1 #bdg ,jehan ,ghir ,%ah diamond1 #afc ,jigg]1 #adi ,jubilee diamond1 #afg ,kauri-gum1 #bii ,khiraj-i-,alam ruby1 #bjf ,kimb]lite1 #aeb ,k+ topaz1 #aha1 #bja ,kle9's solution1 #fg ,koh-i-nor diamond1 #acg1 #aeh ,kunz1 ,dr4 ,g4 ,f41 #ahf1 #bbd1 #bfb1 #bfe ,kunzite1 #bfe ,kyanite1 #gi1 #bgc ,labradorite1 #bee ,la ,pellegr9a pe>l1 #bid ,lapis lazuli1 #bhf ,lazurite1 #bhf ,loz5ge facet1 #ic ,luma*elle1 #bhi ,lu/re1 #cg ,maacles1 ,macles1 #ab1 #aej ,madagasc> /ones1 #aie1 #bbd1 #bdc1 #bfe1 #bff ,mala*ite1 #bhg ,malacolite1 #bgb ,manufactur$ /ones1 #aac ,m>ble1 #bhi ,mattan diamond1 #aee1 #agj ,matura diamonds1 #bcb ,maz>91 ,c>d9al1 #ib ,me]s*aum1 #bhh ,mle1 #acf ,me?yl5e iodide1 #bf1 #ff ,metric c>at1 #he1 #hg ,milky-qu>tz1 #bdj ,m9imum deviation1 #cj ,mo*a-/one1 #bdg ,moe's gauge1 #hg ,mohs's scale ( h>dness1 #gh ,moissan1 ,h5ri1 #aec ,moldavite1 #bhc ,monocl9ic sy/em1 #aa ,moon ( ! ,m\nta9s diamond1 #afb ,moon/one1 #ci1 #bee ,morganite1 #ahf1 #aie ,moroxite1 #bgi ,moss-agate1 #bdg ,"m-(-em]ald1 #bdj ,"m-o'-pe>l1 #bib ,nacre1 #bib ,napoleon diamond1 #afd ,nassak diamond1 #afc ,negative d\ble refraction1 #de ,nephrite1 #bfa ,nicol's prism1 #dd ,nizam diamond1 #afb ,obsidian1 #bhc ,occid5tal topaz1 #aaa1 #bci ,odontolite1 #bei ,(f-col\r$ diamonds1 #acj ,oliv9e 7demantoid71 #baf 7p]idot71 #bbe ,onyx1 #bdg ,opal1 #ci1 #bdi ,fire1 #bea -matrix1 #bea ,opalesc5ce1 #ci ,optical anomalies1 #dg ,optic axes1 #di ,ori5tal alm&9e1 #aab1 #agb ame?y/1 #aaa1 #agb em]ald1 #aaa1 #agb topaz1 #aaa1 #agb ,ori5t ( pe>ls1 #bib ,orl(f diamond1 #afj ,or?oclase1 #bed ,or?orhombic sy/em1 #aa ,pa*a ( ,egypt diamond1 #afe ,pa/e1 #dg1 #abd ,paul ,i diamond1 #aga ,pavilion1 #ic ,pavilion facet1 #ic ,pe>-drop pe>ls1 #bib ,pe>-eye pe>ls1 #bib ,pe>l1 #bia gra91 #hf imitations1 #abf ,p5deloque1 #id ,p]idot1 #bbe ,brazilian1 #bba ,ceylonese1 #bba ,p]uzzi1 ,v9c5zio1 #ib ,ph5akite1 #bfi ,pigott diamond1 #afd ,pipes1 #aeb ,pi/acite1 #bge ,pitt diamond1 #ajj1 #aei ,plasma1 #bdg1 #bfd ,pleo*roism1 #eg ,pleona/e1 #bjd ,pl9y1 #f1 #hh1 #ach1 #ahd1 #aia1 #bda1 #bdi ,pol> ,/> diamond1 #afc ,pol>ization1 #db ,port]-,rhodes diamond1 #aff ,positive d\ble refraction1 #de ,prase1 #bdj1 #bdg ,prehnite1 #bgh ,pycnomet]1 #ge ,pyrites1 #bhb ,pyrope1 #bab ,qu>tz1 #ej1 #bch ,quo9 facet1 #ic ,ra9b[-qu>tz1 #bdj ,recon/ruct$ /ones1 #aaf ,reef1 #add ,reflection ( light1 #ad ,refraction ( light1 #ae ,refractive index1 #af ,refractomet]1 #bb1 #ej ,reg5t diamond1 #ajj1 #aei ,retg]s's salt1 #fi ,rhodes1 ,cecil ,j41 #ade ,rhodesia /ones1 #aee1 #ahc1 #bac1 #bcf ,rhodolite1 #fb1 #bad ,rhodonite1 #bhg ,rock-cry/al1 #ig1 #bci ,rock-drill1 #acd ,rntg5 rays1 #hc ,rose =m ( cutt+1 #ia ,rose-qu>tz1 #bdj ,rospoli sapphire1 #ahb ,rotation ( plane ( pol>ization1 #ej ,rubellite1 #bbj1 #bbc ,rubicelle1 #bjc ,ruby1 #ih1 #aaj1 #agb ,balas-1 #bjc ,cape-1 #bac ,sancy diamond1 #afa ,sapphire1 #ih1 #aaj1 #agb ,brazilian 7t\rmal9e71 #bba -qu>tz1 #bdd ,wat]- 7iolite71 #bff ,wat]- 7topaz71 #bja ,s>d1 #bdg ,s>donyx1 #bdg ,saussurite1 #bfc ,s*orl1 #bba ,sci5tific alex&rite1 #abb brilliant1 #abb em]ald1 #abb topaz1 #aba ,scot* topaz1 #bci ,se$ pe>ls1 #bid ,s]p5t9e1 #bhi ,sett+ ( gem-/ones1 #ajg ,%ah diamond1 #afc ,%e51 #ci ,%eph]d's ,/one diamond1 #afc ,siam /ones1 #ahj ,sib]ia & ,asiatic ,russia /ones1 #ahb1 #ahh1 #aid1 #bja1 #bag1 #bbc1 #bcf1 #bdd1 #bef1 #bfb1 #bfi1 #bgj1 #bhg ,sib]ite1 #bba ,sid]ite1 #bdd ,silv]-?allium nitrate1 #fi ,skew facet1 #ic ,skill facet1 #ic ,smoky qu>tz1 #bdj ,snell's laws1 #af ,soap/one1 #bhh ,sodalite1 #bhf1 #bhg ,son/adt's solution1 #fg ,s\? ,africa /ones1 #aci et seq41 #aff1 #afg et seq41 #bac1 #bcb1 #bdd1 #bfd1 #bga ,spani% topaz1 #bci ,specific gravity1 #fc ,specific-gravity bottle1 #ge ,spectroscope1 #ei ,spectrum1 #bj1 #be ,spectrum1 ,absorption1 #ei ,spess>tite1 #baf ,sph5e1 #bgf ,sp9el1 #bjc ,spodum5e1 #bfe ,spott$ /ones1 #adi ,/>-facet1 #ib ,/> ( ,africa diamond1 #afh ,/> ( ,e/e diamond1 #afe ,/> ( ,m9as diamond1 #afi ,/> ( ,s\? ,africa diamond1 #ada1 #aff ,/> ( ! ,s\? diamond1 #aci1 #afe ,/>/ones1 #ch1 #agg ,/eatite1 #bhh ,/ep =m ( cutt+1 #ih ,/ew>t diamond1 #aff ,/rass1 #abd ,sun/one1 #bee ,syn!tical /ones1 #aac ,syriam1 ,syrian1 g>net1 #bae ,table facet1 #ib ,table =m ( cutt+1 #ia ,tav]ni]1 ,j4 ,b41 #ia1 #abi1 #acg1 #afa1 #afb1 #agj ,templet facet1 #ib ,tetragonal sy/em1 #i ,?ulite1 #bhi ,tiffany diamond1 #aga ,tig]'s-eye1 #ci1 #bdj ,timur ruby1 #bjf ,titanite1 #bgf ,topaz1 #aig ,brazilian1 #aig ,false1 #bci ,occid5tal1 #aaa1 #bci ,ori5tal1 #aaa1 #agc ,sci5tific1 #aba ,scot*1 #bci ,spani%1 #bci ,topazolite1 #baf ,total-reflection1 #ah1 #ba ,t\rmal9e1 #dc1 #bai ,trap =m ( cutt+1 #ih ,tri*roism1 #eg ,tricl9ic sy/em1 #ab ,triplet1 #abf ,turquoise1 #beg ,turquoise-matrix1 #beh ,tuscany diamond1 #afe ,tw9n+1 #ab1 #dg ,uniaxial d\ble refraction1 #de1 #dh #eg ,uralian em]ald1 #bag ,uv>ovite1 #bah ,v>iscite1 #bei ,v]dite1 #bfd ,v]neuil1 ,a4 ,v4 ,l41 #aaf ,vesuvianite1 #bgd ,victoria diamond1 #afg ,violane1 #bhg ,w>t-pe>l1 #bif ,wat] 7( diamonds71 #abi 7( pe>ls71 #bib ,wat]-*rysolite1 #bhd -sapphire 7iolite71 #bff -sapphire 7topaz71 #bja ,:ite opal1 #bdi ,:ite ,saxon diamond1 #afe ,wolla/on1 ,w4 ,h41 #acc ,x-rays1 #hc ,yell[ gr\nd1 #adc ,zircon1 #bbh ,pr9t$ by ,,morrison ,,gibb ,,limit$1 ,ed9burgh ---------------------------------------- ---------------------------- ,,footnotes3 #a ,! ^w m$ium is employ$ by physici/s to express any sub/ance ?r\gh :i* light passes1 & includes solids su* z glass1 liquids su* z wat]1 & gases su* z air2 ! nature ( ! sub/ance is n po/ulat$4 #b ,me?yl5e 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