file :i* includes ! orig9al illu/rations4 ,see #bhjeh-;h4htm or #bhjeh-;h4zip3 7https3_/_/www4gut5b]g4org_/dirs_/#b_/h_ /j_/e_/bhjeh_/bhjeh-;h_/#bhjeh-;h4htm7 or 7https3_/_/www4gut5b]g4org_/dirs_/#b_/h_ /j_/e_/bhjeh_/bhjeh-;h4zip7 ,by ,frank ,b4 ,wade ,diamonds ,a ,text-,book ( ,preci\s ,/ones ,a ,,text-,,book ,,( ,,preci\s ,,/ones ,,= ,,jewel]s ,,& ,,! ,,gem-,,lov+ ,,public by ,,frank ,b4 ,,wade1 ,b4,s4 ,head ( ! ,dep>tm5t ( ,*emi/ry1 ,%ortridge ,high ,s*ool1 ,indianapolis1 ,ind4 ,au?or ( ,diamonds3 ,a ,/udy ( ! ,factors ,t ,gov]n ,_! ,value ,illu/rat$ ,g4 ,p4 ,putnam's ,sons ,new ,york & ,london ,! ,knick]bock] ,press ,copyright1 #aiah by ,frank ,b4 ,wade ,fir/ pr9t+1 ,janu>y1 #aiah ,second ,m>*1 #aibd ,device ,made 9 ! ,unit$ ,/ates ( ,am]ica ,,preface ,9 ?is little text-book ! au?or has tri$ to comb9e ! trade in=mation :i* he has ga9$ 9 8 avocation1 ! /udy ( preci\s /ones1 ) ! sci5tific k be>+ !reon1 :i* 8 vocation1 ! tea*+ ( *emi/ry1 has compell$ him to ma/]4 ,9 plann+ & 9 writ+ ! book1 e ef=t has be5 made to tea* ! fundam5tal pr9ciples & me?ods 9 use = id5tify+ preci\s /ones1 9 z natural an ord] z possible4 ,?is has be5 done 9 ! belief t ! necess>y in=mation w ?us be mu* m readily acquir$ by ! busy gem m]*ant or jewel] ?an w\ld h be5 ! case _h ! mat]ial be5 arrang$ 9 ! usual sy/ematic ord]4 ,! latt] is ( advantage = quick ref]5ce aft] ! fundam5tals ( ! subject h be5 ma/]$4 ,x is hop$1 h[ev]1 t ! me?od ( pres5tation us$ 9 ?is book w make easy ! acquisition ( a k ( gemology & t _m :o h be5 det]r$ f /udy+ ! subject by a feel+ t ! difficulties due to _! lack ( sci5tific tra9+ 7 insurm\ntable1 w f9d t !y c le>n all ! sci5ce t is really necess>y1 z !y proce$4 ,to t end ! discussions h be5 giv5 9 z unte*nical language z possible & homely illu/rations h 9 _m cases be5 provid$4 ,ne>ly e portion ( ! subject t a gem m]*ant ne$s to "k has be5 consid]$ & !re is provid$ = ! int]e/$ public mu* mat]ial :i* w enable !m to be m intellig5t pur*as]s ( gem-set jewelry1 z well z m appreciative lov]s ( ,nature's wond]ful m9]al ma/]pieces4 ,f4 ,b4 ,w4 ,,indianapolis1 ,decemb] #bf1 #aiaf ,,introduction ,because ( ! rapid increase 9 k ab\t preci\s /ones on ! "p ( ! buy+ public1 x has become necess>y = ! gem m]*ant & 8 cl]ks & salesm5 to "k at lea/ z mu* ab\t ! subject ( gemology z _! bett] in=m$ cu/om]s are likely to "k4 ,9 _m rec5t articles 9 trade pap]s1 att5tion has be5 call$ to ?is ne$1 & to ! provision :i* ,columbia ,univ]sity has made = a c\rse 9 ! /udy ( gems4 ,! action ( ! ,national ,association ( ,goldsmi?s ( ,great ,brita9 9 provid+ annual exam9ations 9 gemology1 & 9 grant+ c]tificates & diplomas to ^? :o successfully pass ! exam9ations1 has also be5 report$1 & x has be5 sugge/$ t "s su* c\rse %\ld be pursu$ by jewel]s' associations 9 ?is c\ntry4 ,! greate/ difficulty 9 ! way ( su* =mal /udy among our jewel]s & gem m]*ants is ! lack ( "t = att5dance on =mal c\rses1 :i* mu/ necess>ily be giv5 at def9ite times & 9 def9ite places4 ,z a diamond salesman 0 he>d to say rec5tly3 ,! boss said he want$ me to take 9 t c\rse at ,columbia1 b he didn't tell me h[ ,i 0 go+ to d x4 ,"h ,i am a ?\s& miles f ,columbia1 & x 0 only six weeks ago t he 0 tell+ me ,i ought to take t c\rse4 ,i c't /ay ar\nd ,new ,york all ! "t4 ,simil>ly ^? ^: "w keeps !m 9 ,new ,york might object t _! h\rs ( employm5t prev5t$ att5dance on day c\rses1 & t di/ance f ! univ]sity & fatigue prev5t att5dance on night c\rses4 ,! great mass ( gem deal]s 9 o!r cities mu/ also be consid]$4 ,x w !re=e be ! endeavor ( ?is book to provide guidance = ^? :o really want to make !mselves m effici5t 9 ! gem bus9ess1 b :o h felt t !y ne$$ some?+ 9 ! way ( sugge/ion reg>d+ :at to attempt1 & h[ to g ab\t x4 ,/udy ( ! sort t w be sugge/$ c be pursu$ 9 sp>e mom5ts1 on /reet c>s or elevat$ tra9s1 9 wait+ rooms1 or 9 "o's room at night4 ,x w a/oni% _m to f9d h[ mu* c be accompli%$ by consi/5tly utiliz+ sp>e mom5ts4 ,book] ,t4 ,wa%+ton is said to h writt5 9 su* sp>e "t practically all t he has publi%$4 ,= ! practical /udy ( ! gems !mselves1 :i* is an absolutely ess5tial "p ( ! "w1 ^? actually engag$ 9 ! trade h bett] opportunities ?an any s*ool c\ld give &1 except dur+ ru% seasons1 !re is pl5ty ( "t dur+ bus9ess h\rs = su* /udy4 ,no intellig5t employ] w begrudge su* use ( "t = :i* he is pay+1 if ! ?+ be done 9 reason & ) a s]i\s view to improvem5t4 ,! frequ5t application ( :at is acquir$1 z opportunity (f]s1 9 connection ) ord9>y salesman%ip1 w help fix ! subject & at ! same "t increase sales4 ,_m gem deal]s h be5 det]r$ f beg9n+ a /udy ( gems because ( ! seem+ difficulties 9 connection ) ! sci5tific det]m9ation ( ! diff]5t v>ieties ( /ones4 ,n[ sci5ce is no?+ b boil$-d[n common s5se1 & a bold front w soon conv9ce "o t mo/ ( ! difficulties are m app>5t ?an real4 ,su* m9or difficulties z exi/ w be approa*$ 9 su* a mann] t a little ef=t w ov]come !m4 ,= ^? :o are will+ to d m "w1 ?is book w sugge/ def9ite portions ( p>ticul> books1 :i* are easily available1 = ref]5ce read+ & /udy--b ! lessons !mselves w attempt to tea* ! ess5tial ?+s 9 z simple a mann] z is possible4 ,p]haps ! fir/ ess5tial = ! gem m]*ant is to be able surely to di/+ui% ! v>i\s /ones f "o ano!r & f syn!tic & imitation /ones4 ,t su* ability is mu* ne$$ w be cle> to anyone :o 9 ca/+ a backw>d glance ov] 8 exp]i5ce recalls ! _m s]i\s mi/akes t h come to 8 k4 ,_m m h d\btless occurr$ )\t detection4 ,sev]al times rec5tly ! au?or has come across cases :]e l>ge deal]s h be5 mi/ak5 9 _! det]m9ation ( color$ /ones1 p>ticul>ly em]alds4 ,only ! o!r day a r+ 0 br\ght to me t _h be5 b\ght = a g5u9e em]ald r+ aft] ! buy] _h tak5 x to "o ( ! deal]s 9 8 city & _h paid = an exam9ation ( x1 :i* _h result$ 9 its be+ decl>$ g5u9e4 ,on exam9+ ! /one ) a l5s ( only mod]ate p[]1 sev]al r\nd air bubbles 7 not$ 9 x1 & on b>ely t\*+ x ) a file x 0 easily scrat*$4 ,! mat]ial 0 gre5 glass4 ,n[1 :at 0 said ab\t ! deal] :o sold x & ! "o :o apprais$ x may be imag9$4 ,! long *a9 ( adv]se influ5ce :i* w be put 9 action aga9/ ^? deal]s1 ev5 ?\gh ! "o :o sold ! /one makes good ! loss1 is some?+ t c be ill af=d$ by any deal]1 & all ?is might h be5 avoid$ by ev5 a rudim5t>y k ( ! means ( di/+ui%+ preci\s /ones4 ,! deal] 0 d\btless hone/1 b1 ?r\gh c>elessness or ignorance1 0 himself deceiv$4 ,our fir/ few lessons w !re=e be conc]n$ *iefly ) le>n+ ! be/ means ( tell+ ! diff]5t /ones f "o ano!r4 ,,cont5ts ,,page ,,preface iii ,,lesson ,i4--,,h[ ,,/ones ,,are ,,di/+ui%$ ,,f ,,"o ,,ano!r #a ,,ii4--,,refraction #d ,,iii4--,,d\ble ,,refraction #h ,,iv4--,,absorption ,,& ,,di*roism #ae ,v4--,,specific ,,gravity #bc ,,vi4--,,specific ,,gravity ,,det]m9ations #ca ,,vii4--,,lu/] ,,& ,,o!r ,,reflection ,,effects #ch ,,viii4--,,h>dness #dg ,,ix4--,,h>dness 7,cont9u$7 #ee ,x4--,,disp]sion #fj ,,xi4--,,color #ff ,,xii4--,,color 7,cont9u$7 #ge ,,xiii4--,,color 7,cont9u$7 #hg ,,xiv4--,,color 7,conclud$7 #ic ,,xv4--,,h[ ,,to ,,tell ,,sci5tific ,,/ones ,,f ,,natural ,,gems #ii ,,xvi4--,,h[ ,,to ,,te/ ,,an ,,unkn[n ,,gem #aji ,,xvii4--,,suitability ,,( ,,/ones ,,= ,,v>i\s ,,types ,,( ,,jewels1 ,,z ,,det]m9$ ,,by ,,h>dness1 ,,brittl5ess1 ,,& ,,cleavability #aai ,,xviii4--,,m9]al ,,species ,,to ,,:i* ,,! ,,v>i\s ,,gems ,,belong ,,& ,,! ,,*emical ,,composition ,,!re( #acc ,,xix4--,,! ,,nam+ ,,( ,,preci\s ,,/ones #adi ,,xx4--,,! ,,nam+ ,,( ,,preci\s ,,/ones 7,conclud$7 #afd ,,xxi4--,,:]e ,,preci\s ,,/ones ,,are ,,f\nd #agi ,,xxii4--,,h[ ,,r\gh ,,preci\s ,,/ones ,,are ,,cut #bja ,,xxiii4--,,h[ ,,r\gh ,,preci\s ,,/ones ,,are ,,cut ,,& ,,:at ,,con/itutes ,,good ,,make 7,conclud$7 #bac ,,xxiv4--,,=ms ,,giv5 ,,to ,,preci\s ,,/ones #bbg ,,xxv4--,,imitations ,,( ,,preci\s ,,/ones #bcg ,,xxvi4--,,alt]ation ,,( ,,! ,,color ,,( ,,preci\s ,,/ones #bej ,,xxvii4--,,pe>ls #beh ,,xxviii4--,,cultur$ ,,pe>ls ,,& ,,imitations ,,( ,,pe>ls #bgg ,,xxix4--,,! ,,use ,,( ,,balances ,,& ,,! ,,unit ,,( ,,weight ,,9 ,,use ,,= ,,preci\s ,,/ones #bhc ,,xxx4--,,t>iff ,,laws ,,on ,,preci\s ,,& ,,imitation ,,/ones #bid ,,bibliography #cja ,,index #cac ,a ,text-,book ( ,preci\s ,/ones ,,lesson ,i ,,h[ ,,/ones ,,are ,,di/+ui%$ ,,f ,,"o ,,ano!r ,,preci\s ,,/ones ,,di/+ui%$ ,,by ,,_! ,,prop]ties4 ,"o preci\s /one is be/ di/+ui%$ f ano!r j z sub/ances ( o!r types are di/+ui%$1 t is to say1 by _! prop]ties4 ,= example1 salt & sug> are bo? :ite1 bo? are soluble 9 wat]1 & bo? are odorless4 ,s f> ! italiciz$ prop]ties w\ld n s]ve to di/+ui% ! two sub/ances4 ,b sug> is sweet :ile salt is salty 9 ta/e4 ,"h we h a di/+ui%+ prop]ty4 ,n[1 j z salt & sug> h prop]ties1 s h all preci\s /ones1 & :ile1 z 0 ! case ) salt & sug>1 _m preci\s /ones h prop]ties 9 common1 yet ea* has also "s prop]ties :i* are di/9ctive1 & :i* c be reli$ ^u z diff]5tiat+ ! p>ticul> /one f o!r /ones4 ,9 select+ prop]ties = use 9 di/+ui%+ preci\s /ones1 su* prop]ties z c be det]m9$ by quantity1 & set d[n 9 numb]s1 are probably m tru/wor?y ?an ^? t c be obs]v$ by m]e inspection4 ,^? also :i* h to d ) ! behavior ( light 9 pass+ ?r\gh ! /one are extremely valuable4 ,,importance ,,( ,,num]ical ,,prop]ties4 ,x is because gem deal]s s (t5 rely ^u ! m obvi\s sort ( prop]ty1 su* z color1 t !y s frequ5tly make mi/akes4 ,!re may be sev]al diff]5t types ( /ones ( a giv5 color1 b ea* w be f\nd to h its own num]ical prop]ties su* z d5sity1 h>dness1 refractive p[]1 disp]sive p[]1 etc41 & x is only by an accurate det]m9ation ( two or ?ree ( ^! t "o c be sure :at /one he has 9 h&4 ,x mu/ next be our task to f9d exactly :at is meant by ea* ( ^! num]ical prop]ties1 & h[ "o may det]m9e ea* ) ease & exactness4 ,,lesson ,,ii ,,refraction ,,explanation ,,( ,,refraction4 ,p]haps ! sure/ s+le me?od ( di/+ui%+ preci\s /ones is to f9d out ! refractive index ( ! mat]ial4 ,to "o n acqua9t$ ) ! sci5ce ( physics ?is calls = "s explanation4 ,! t]m refraction is us$ to describe ! b5d+ :i* light und]goes :5 x passes 7at any angle b a "r angle7 f "o transp>5t m$ium to ano!r4 ,= example1 :5 light passes f air into wat]1 its pa? is b5t at ! surface ( ! wat] & x takes a new direction )9 ! wat]4 7,see ,fig4 #a47 ,illu/ration3 ,,fig4 #a4 ,,ab repres5ts ! pa? ( light 9 ! air & ,,bc its pa? 9 ! wat]4 ,:ile e gem /one refracts light :i* ent]s x f ! air1 ea* /one has its own def9ite ability to d ?is1 & ea* diff]s f e o!r 9 ! am\nt ( b5d+ :i* x c br+ ab\t "u giv5 conditions4 ,! accurate det]m9ation ( ! am\nt ( b5d+ 9 a giv5 case requires v f9ely con/ruct$ optical in/rum5ts & also a k ( h[ to apply a c]ta9 am\nt ( ma!matics4 ,h[ev]1 all ?is "p ( ! "w has already be5 done by compet5t sci5ti/s1 & tables h be5 prep>$ by !m1 9 :i* ! values = ea* mat]ial are put d[n4 ,,! ,,h]b]t-,,smi? ,,refractomet]4 ,!re is on ! m>ket an in/rum5t call$ ! ,h]b]t-,smi? refractomet]1 by means ( :i* anyone ) a little practice c read at once on ! scale )9 ! in/rum5t ! refractive index1 z x is call$1 ( any preci\s /one t is n too highly refractive4 7,its upp] limit is #a4hj4 ,?is w\ld exclude v few /ones ( importance1 i4 e41 zircon1 diamond1 sph5e1 & demantoid g>net47 ,^? read]s :o wi% to make a m int5sive /udy ( ! con/ruction & use ( ! refractomet] w f9d a v full & complete acc\nt ( ! subject 9 ,gem-,/ones & _! ,di/9ctive ,*>act]s1 by ,g4 ,f4 ,h]b]t-,smi?1 ,new ,york2 ,james ,pott ,co41 #aiab4 ,*apt] ,,iv41 pp4 #ba-cf4 ,! ,h]b]t-,smi? refractomet] is !re describ$ fully1 its pr9ciple is expla9$ & directions = us+ x are giv54 ,! price ( ! refractomet] is necess>ily s high 7duty includ$7 t its pur*ase might n be ju/ifi$ 9 ! case ( ! small] retail]4 ,e l>ge deal] 9 color$ /ones1 :e!r import]1 :olesal]1 or retail]1 %\ld h "o1 z by its use v rapid & v accurate det]m9ations ( /ones may be made1 & its use is n conf9$ to unm\nt$ /ones1 = any /one ^: table facet c be appli$ to ! surface ( ! l5s 9 ! in/rum5t c be det]m9$4 ,,lesson ,,iii ,,d\ble ,,refraction ,,explanation ,,( ,,d\ble ,,refraction4 ,9 ,lesson ,,ii4 we le>n$ :at is meant by refraction ( light4 ,:ile glass & a small numb] ( preci\s /ones 7diamond1 g>net1 & sp9el7 b5d light z 0 illu/rat$ 9 ,fig4 #a1 practically all ! o!r /ones cause a beam ( light on ent]+ !m to sep>ate1 & ! pa? ( ! light 9 ! /one becomes d\ble1 z %[n 9 ,fig4 #b4 ,?is behavior is call$ d\ble refraction4 ,x may be us$ to di/+ui% ^? /ones :i* are d\bly refract+ f ^? :i* are n4 ,= example1 9 ! case ( a /one :i* is d\bly refract+ to a /rong degree1 su* z a p]idot 7! light] yell[i%-gre5 *rysolite is ! same mat]ial & behaves simil>ly t[>d light71 ! sep>ation ( ! light is s m>k$ t ! edges ( ! re> facets1 z se5 ?r\gh ! table1 appe> d\ble :5 view$ ?r\gh a l5s4 ,a zircon w also simil>ly sep>ate light & its re> facets also appe> d\ble-l9$ z se5 ) a l5s f ! table ( ! /one4 ,! r>] /ones1 sph5e & epidote1 likewise exhibit ?is prop]ty m>k$ly4 ,"s colorless zircons1 :5 well cut1 s closely resemble diamonds t ev5 an exp]t might be deceiv$1 if caught (f 8 gu>d1 b ?is simple te/ ( look+ = ! d\bl$ l9es at ! back ( ! /one w\ld alone s]ve to di/+ui% ! two /ones4 ,illu/ration3 ,,fig4 #b4 ,a ,,simple ,,b ,,v ,,valuable ,,te/ ,,= ,,! ,,k9d ,,( ,,refraction ,,( ,a ,,cut ,,/one4 ,9 ! case ( mo/ ( ! o!r d\bly refract+ /ones ! degree ( sep>ation is mu* less ?an 9 p]idot & zircon1 & x takes a well-tra9$ & c>eful eye to detect ! d\bl+ ( ! l9es4 ,"h a v simple device w s]ve to assi/ ! eye 9 det]m9+ :e!r a cut /one is s+ly or d\bly refract+4 ,expose ! /one to direct sunlight & hold an opaque :ite c>d a few in*es f ! /one1 9 ! direction ( ! sun1 s z to get ! bright reflections f )9 ! /one reflect$ onto ! c>d4 ,if ! mat]ial is s+ly refractive 7z 9 ! case ( diamond1 g>net1 sp9el1 & glass71 s+le images ( ea* ( ! reflect+ facets w appe> on ! c>d1 b if d\bly refract+--ev5 if slightly s--d\ble images w appe>4 ,:5 ! /one is slightly mov$1 ^! pairs ( reflections w travel toge!r z pairs & n t5d to sep>ate4 ,! space betwe5 ! two memb]s ( ea* pair ( reflections s]ves to give a r\gh idea ( ! degree ( ! d\ble refraction ( ! mat]ial if comp>$ ) ! space betwe5 memb]s 9 ! case ( "s o!r k9d ( /one held at ! same di/ance f ! c>d4 ,?us zircon sep>ates ! reflections widely4 ,aquam>9e1 :i* is feebly d\bly refract+1 sep>ates !m b slightly4 ,x w be se5 at once t we h "h a v easily appli$ te/ & "o t requires no co/ly app>atus4 ,x is1 fur!rmore1 a sure te/1 aft] a little practice4 ,= example1 if "o has some?+ t looks l a f9e em]ald1 b t may be glass1 all "o ne$ to d is to expose x 9 ! sun1 z above indicat$4 ,if real em]ald1 d\ble images w be _h 7v close toge!r1 because em]ald is b feebly d\bly refract+74 ,if glass1 ! images on ! c>d w be s+le4 ,simil>ly1 ruby c at once be di/+ui%$ f ev5 ! f9e/ g>net or ruby sp9el1 z ! la/ two are s+ly refract+4 ,s1 too1 are glass imitations ( ruby & ruby d\blets 7:i* consi/ ( glass & g>net74 ,?is te/ _c injure ! /one1 x may be appli$ to m\nt$ /ones1 & x is reliable4 ,= /ones ( v deep color ?is te/ may fail = lack ( suffici5tly brilliant reflections4 ,9 su* a case hold ! c>d beyond ! /one & let ! sunlight %9e ?r\gh ! /one onto ! c>d1 obs]v+ :e!r ! spots ( light are s+le or d\ble4 ,! table bel[ gives ! necess>y in=mation z to :i* /ones %[ d\ble & :i* s+le refraction4 ,,table ,,giv+ ,,"* ,,( ,,refraction ,,9 ,,! ,,pr9cipal ,,gems ,refraction ,s+le3 ,diamond ,g>net 7all types7 ,sp9el ,opal ,glass ,diff]5ce betwe5 highe/ & l[e/ refractive indices ,refraction ,d\ble3 ,sph5e 4#jhd ,zircon 4#jec ,b5itoite 4#jdg ,p]idot or *rysolite 4#jch ,epidote 4#jca ,t\rmal9e 4#jbj ,kunzite 4#jae ,ruby & sapphire 4#jji ,topaz 7preci\s7 4#jji ,ame?y/ & qu>tz topaz 4#jji ,em]ald & aquam>9e 4#jjg ,*rysob]yl 4#jjg ,! /ud5t %\ld n[ put into practice ! me?ods sugge/$ 9 ?is lesson4 ,look fir/ = ! visible d\bl+ ( ! l9es ( ! back facets 9 p]idot 7or *rysolite72 !n 9 zircon2 !n 9 "s ( ! less /rongly d\bly refract+ /ones2 !n try ! sunlight-c>d me?od ) g5u9e /ones & ) d\blets & imitations until y c tell e "t :e!r y are deal+ ) s+ly or d\bly refract+ mat]ial4 ,:5 a /one ( unkn[n id5tity comes along1 try ! me?od on x & ?us assign x z a fir/ /ep to "o or ! o!r class4 ,o!r te/s w !n be necess>y to def9itely place x4 ,,diff]5ces ,,9 ,,refraction ,,due ,,to ,,cry/al ,,=m4 ,! diff]5ce 9 behavior t[>d light ( ! s+ly & d\bly refract+ m9]als dep5ds ^u ! cry/al /ructure ( ! m9]al4 ,all gems ^: cry/als belong 9 ! cubic sy/em are s+ly refract+ 9 all directions3 ,9 ! case ( "s o!r sy/ems ( cry/als ! mat]ial may be s+ly refract+ 9 "o or 9 two directions1 b d\bly refract+ 9 o!r directions4 ,no att5tion ne$ be paid to ^! complications1 h[ev]1 :5 us+ ! sunlight-c>d me?od ) a cut /one1 = 9 su* a case ! light 9 its c\rse )9 ! /one w h cross$ ! mat]ial 9 two or m directions1 & ! sep>ation & consequ5t d\bl+ ( image w be sure to result4 ,= ^? :o wi% to /udy d\ble refraction m 9 detail1 ,*apt] ,,vi41 pages #dj-eb1 ( ,g4 ,f4 ,h]b]t-,smi?'s ,gem-,/ones w s]ve admirably z a text4 ,z an alt]native any text-book on physics w answ]4 ,,lesson ,,iv ,,absorption ,,& ,,di*roism ,,cause ,,( ,,color ,,9 ,,m9]als4 ,9 ,lesson ,,iii4 we saw t _m gem mat]ials cause light t ent]s !m to divide & take two pa?s )9 ! mat]ial4 ,n[ all transp>5t mat]ials absorb light m or less2 t is1 !y /op "p ( x1 p]haps conv]t+ x into heat1 & less light em]ges ?an ent]$ ! /one4 ,if light ( all ! ra9b[ colors 7r$1 orange1 yell[1 gre51 blue1 violet7 is equally absorb$1 s t !re is ! same relative am\nt ( ea* 9 ! light t comes out z 9 ! light t w5t into a /one1 we say t ! /one is a :ite /one2 t is1 x is n a color$ /one4 ,if1 h[ev]1 only blue light succe$s 9 gett+ ?r\gh1 ! re/ ( ! :ite light t ent]$ be+ absorb$ )91 we say t we h a blue /one4 ,simil>ly1 ! color ( any transp>5t mat]ial dep5ds ^u its relative degree ( absorption ( ea* ( ! colors 9 :ite light4 ,t color :i* em]ges mo/ successfully gives its "n to ! color ( ! /one4 ,?us a ruby is r$ because r$ light succe$s 9 pass+ ?r\gh ! mat]ial mu* bett] ?an light ( any o!r color4 ,,unequal ,,absorption ,,causes ,,di*roism4 ,all t has be5 said s f> applies equally well to bo? s+ly & d\bly refract+ mat]ials1 b 9 ! latt] sort x is frequ5tly ! case1 9 ^? directions 9 :i* light always divides1 t ! absorption is n equal 9 ! two beams ( light 7"o is call$ ! ord9>y ray & ! o!r ! extraord9>y ray74 ,= example1 9 ! case ( a cry/al ( ruby1 if :ite light />ts to cross ! cry/al1 x n only divides into an ord9>y ray & an extraord9>y ray1 b ! absorption is diff]5t 9 ! two cases1 & ! two rays em]ge ( diff]5t %ades ( r$4 ,) mo/ rubies "o ray em]ges purpli% r$1 ! o!r yell[i% r$4 ,x w at once be se5 t if ! human eye c\ld di/+ui% betwe5 ! two rays1 we w\ld h "h a spl5did me?od ( det]m9+ _m preci\s /ones4 ,un=tunately1 ! eye does n analyze light1 b r bl5ds ! effect s t ! unaid$ eye gives b a poor means ( tell+ :e!r or n a /one exhibits tw9 colors1 or di*roism1 z x is call$4 7,! t]m signifies two colors47 ,a well-tra9$ eye c1 h[ev]1 by view+ a /one 9 sev]al diff]5t positions1 note ! diff]5ce 9 %ade ( color caus$ by ! diff]5tial absorption4 ,,! ,,di*roscope4 ,n[1 ?anks to ! sci5tific work]s1 !re has be5 devis$ a relatively simple & comp>atively inexp5sive in/rum5t call$ ! di*roscope1 :i* enables "o to tell almo/ at a glance :e!r a /one is or is n di*roic4 ,! con/ruction is indicat$ 9 ! accompany+ draw+ & description4 ,illu/ration3 ,,! ,,di*roscope4 ,illu/ration3 ,,fig4 #c4 ,a1 simple l5s2 ,b1 piece ( ,icel& sp> ) glass prisms on ends to squ>e !m up2 ,c1 squ>e hole4 ,illu/ration3 ,,fig4 #d4 ,if ! obs]v] looks ?r\gh ! l5s 7,a7 t[>d a bright light1 z1 = example1 ! sky1 he app>5tly sees two squ>e holes1 ,fig4 #d4 ,:at has happ5$ is t ! light pass+ ?r\gh ! squ>e hole 7,c ( ,fig4 #c7 has divid$ 9 pass+ ?r\gh ! /rongly d\bly refract+ ,icel& sp> 7,b ( ,fig4 #c7 & two images ( ! squ>e hole are ?us produc$4 ,if n[ a /one t exhibits di*roism is held 9 front ( ! squ>e hole & view$ t[>d ! light1 two images ( ! /one are se51 "o due to its ord9>y ray 7:i*1 z 0 said above1 w h "o color71 & ! o!r due to its extraord9>y ray 7:i* w h a diff]5t color or %ade ( color71 ?us ! color ( ! two squ>es w be diff]5t4 ,) a s+ly refract+ m9]al1 or ) glass1 or ) a d\bly refract+ m9]al :5 view$ 9 c]ta9 directions ( ! cry/al 7:i* d n yield d\ble refraction7 ! colors w be alike 9 ! two squ>es4 ,?us to det]m9e :e!r a r$ /one is or is n a ruby 7x might be a g>net or glass or a d\blet1 all ( :i* are s+ly refract+ & h5ce c %[ no di*roism71 hold ! /one be=e ! hole 9 ! di*roscope & note :e!r or n x produces tw9 colors4 ,if !re seems to be no diff]5ce ( %ade turn ! /one ab\t1 z x may h accid5tally be5 plac$ s t x 0 view$ along its direction ( s+le refraction4 ,if !re is /ill no di*roism x is n a ruby4 7,note4--,sci5tific rubies exhibit di*roism z well z natural ones1 s ?is te/ w n di/+ui% !m47 ,a di*roscope may be _h = f sev5 to t5 doll>s1 accord+ to ! make1 & ev]yone :o deals 9 color$ /ones %\ld own & use "o4 ,n all /ones t are d\bly refract+ exhibit di*roism4 ,:ite /ones ( c\rse _c exhibit x ev5 ?\gh d\bly refract+1 & "s color$ /ones1 ?\gh /rongly d\bly refract+1 d n exhibit any noticeable di*roism4 ,! zircon1 = example1 is /rongly d\bly refract+1 b %[s h>dly any di*roism4 ,! te/ is mo/ useful = em]ald1 ruby1 sapphire1 t\rmal9e1 kunzite & alex&rite1 all ( :i* %[ m>k$ di*roism4 ,x is ( little use to give "h ! tw9 colors 9 ea* case z ! %ades diff] ) diff]5t specim5s1 accord+ to _! dep? & type ( color4 ,! deep] t9t$ /ones ( any species %[ ! effect m m>k$ly ?an ! light] ones4 ,! me?od is rapid & easy--x c be appli$ to m\nt$ /ones z well z to loose ones1 & x _c injure a /one4 ,! /ud5t %\ld1 if possible1 obta9 ! use ( a di*roscope & practice ) x on all sorts ( /ones4 ,he %\ld especially become exp]t 9 di/+ui%+ betwe5 rubies1 sapphires1 & em]alds1 & _! imitations4 ,! only imitation 7sci5tific rubies & sapphires are n "h class$ z imitations71 :i* is at all likely to deceive "o :o kn[s h[ to use ! di*roscope is ! em]ald triplet1 made ) real 7b pale7 b]yl above & bel[1 ) a ?9 /rip ( gre5 glass betwe54 ,z b]yl is d\bly refract+ to a small degree1 & di*roic1 "o might p]haps be deceiv$ by su* an imitation if n c>eful4 ,h[ev]1 ! am\nt ( di*roism w\ld be less 9 su* a case ?an 9 a true em]ald ( z deep a color4 ,^? :o wi% to /udy fur!r ! subject ( di*roism %\ld see ,gem-,/ones1 by ,g4 ,f4 ,h]b]t-,smi?1 ,*apt] ,,vii41 pp4 #ec-ei1 or see ,a ,h&book ( ,preci\s ,/ones1 by ,m4 ,d4 ,ro?s*ild1 ,putnam's1 pp4 #ad-af4 ,,lesson ,v ,,specific ,,gravity ,! prop]ties s f> consid]$ z s]v+ to di/+ui% preci\s /ones h all dep5d$ ^u ! behavior ( ! mat]ial t[>d light4 ,^! prop]ties 7 consid]$ fir/ because !y af=d1 to ^? acqua9t$ ) _! use1 v rapid & sure means ( classify+ preci\s /ones4 ,,d5sity ,,( ,,m9]als4 ,we w next consid] an equally c]ta9 te/1 :i*1 h[ev]1 requires r m "t1 app>atus1 & skill to apply4 ,ea* k9d ( preci\s /one has its own d5sity4 ,t is1 if pieces ( diff]5t /ones 7 tak5 all ( ! same size1 ! weights w\ld diff]1 b l-siz$ pieces ( "o & ! same mat]ial always h ! same weight4 ,x is ! cu/om among sci5ti/s to comp>e ! d5sities ( sub/ances ) ! d5sity ( wat]4 ,! numb] :i* expresses ! relation betwe5 ! d5sity ( any sub/ance & ! d5sity ( wat] is call$ ! specific gravity numb] ( ! sub/ance4 ,= example1 if1 size = size1 a mat]ial1 say diamond1 is #c4ea times z heavy z wat]1 its specific gravity is #c4ea4 ,x w be se5 t s9ce ea* sub/ance always has1 :5 pure1 ! same specific gravity1 we h "h a means ( di/+ui%+ preci\s /ones4 ,x is v seldom1 if ev]1 ! case t we f9d any two preci\s /ones ( ! same specific gravity4 ,a few /ones h ne>ly ! same specific gravities1 & 9 su* cases x is well to apply o!r te/s also4 ,9 fact "o %\ld always make sure ( a /one by see+ t two or ?ree diff]5t te/s po9t to ! same species4 ,we mu/ next f9d out h[ to det]m9e ! specific gravity ( a preci\s /one4 ,if ! %ape ( a /one 7 su* t ! volume c\ld be readily calculat$1 !n "o c\ld easily comp>e ! weight ) ! volume or ) ! weight ( ! same volume ( wat]1 & ?us get ! specific gravity 7= a specific gravity numb] really tells h[ mu* heavi] a piece ( mat]ial is ?an ! same volume ( wat]74 ,un=tunately ! =m ( mo/ preci\s /ones is su* t x w\ld be v difficult to calculate ! volume f ! measurem5ts1 & ! latt] w\ld be h>d to make accurately ) small /ones4 ,to avoid ^! difficulties ! foll[+ +5i\s me?od has be5 devis$3 ,if a /one is dropp$ into wat] x pu%es aside1 or displaces1 a body ( wat] exactly equal 9 volume to itself4 ,if ! wat] ?us displac$ 7 caught & weigh$1 & ! weight ( ! /one !n divid$ by ! weight ( ! wat] displac$1 we w\ld h ! specific gravity numb] ( ! /one4 ,?is is precisely :at is done 9 gett+ ! specific gravity ( small /ones4 ,to make sure ( gett+ an accurate result = ! weight ( wat] displac$ ! foll[+ app>atus is us$4 ,illu/ration3 ,,fig4 #e4 ,a1 ,flask-l ,bottle2 ,b1 ,indicates ,gr\nd ,glass ,/opp]2 ,c1 ,%[s ,hole ,drill$ ?r\gh ,/opp]4 ,,! ,,specific ,,gravity ,,bottle4 ,a small flask-l bottle 7see ,fig4 #e7 is obta9$4 ,?is has a tightly fitt+ gr\nd glass /opp] 7,b74 ,! /opp] has a small hole 7,c7 drill$ ?r\gh x l5g?wise4 ,if ! bottle is fill$ ) wat]1 & ! /opp] dropp$ 9 & tight5$1 wat] w squirt out ?r\gh ! small hole 9 ! /opp]4 ,on wip+ (f /opp] & bottle we h ! bottle exactly full ( wat]4 ,if n[ ! /opp] is remov$1 ! /one to be te/$ 7:i* mu/ ( c\rse be small] ?an ! neck ( ! bottle7 dropp$ 91 & ! /opp] replac$1 exactly z mu* wat] w squirt out z is equal 9 volume to ! /one t 0 dropp$ 94 ,if we _h weigh$ ! full bottle ) ! /one on ! pan beside x1 & !n weigh$ ! bottle ) ! /one inside x we c\ld n[1 by subtract+ ! la/ weight f ! fir/1 f9d out h[ mu* ! wat]1 t 0 displac$1 weigh$4 ,?is is precisely ! ?+ to d4 ,! weight ( ! /one be+ kn[n we n[ h m]ely to divide ! weight ( ! /one by ! weight ( ! displac$ wat]1 & we h ! specific gravity numb]4 ,ref]5ce to a table ( specific gravities ( preci\s /ones w enable u to "n our /one4 ,su* a table foll[s ?is lesson4 ,a ,,sample ,,calculation4 ,! actual p]=mance ( ! op]ation1 if "o is skill$ 9 weigh+1 takes less "t ?an x w\ld to read ?is description4 ,at fir/ "o w be sl[1 & p]haps "o %\ld read & re-read ?is lesson1 mak+ sure t all ! ideas are cle> be=e try+ to put !m 9 practice4 ,a sample calculation may help make ! matt] cle>]1 s "o is app5d$3 ,weight ( bottle /one 7outside7 #ec4ea c>ats ,weight ( bottle /one 7inside7 #eb4ea c>ats ------------ ,weight ( wat] displac$ #a4jj c>at ------------ ,weight ( /one #c4ea c>ats ,weight ( /one #c4ea ,specific gravity --------------- ---- #c4ea ,sp4 g4 ,weight ( wat] #a4jj ,9 ?is case ! specific gravity be+ #c4ea1 ! /one is probably diamond 7see table71 b might be preci\s topaz1 :i* has ne>ly ! same specific gravity4 ,x is assum$ t ! jewel] w weigh 9 c>ats1 & t 8 balance is s5sitive to 4#ja c>at4 ,) su* a balance1 & a specific gravity bottle 7:i* any sci5tific supply h\se w furni% = less ?an #a7 results suffici5tly accurate = ! det]m9ation ( preci\s /ones may be _h if "o is c>eful to exclude air bubbles f ! bottle1 & to wipe ! outside ( ! bottle p]fectly dry be=e ea* weigh+4 ,! bottle %\ld nev] be held 9 ! w>m h&s1 or x w act l a !rmomet] & exp& ! wat] up ! n>r[ tube 9 ! /opp]1 ?us lead+ to error4 ,a h&k]*ief may be us$ to grasp ! bottle4 ,,table ,,( ,,specific ,,gravities ,,( ,,! ,,pr9cipal ,,gem ,,mat]ials ,b]yl 7,em]ald7 #b4gd ,*rysob]yl 7,alex&rite7 #c4gc ,corundum 7,ruby1 sapphire1 ,ori5tal topaz7 #d4jc ,diamond #c4eb ,g>net 7,pyrope7 #c4gh 7,hessonite7 #c4fa 7,demantoid1 kn[n 9 ! trade z ,oliv9e7 #c4hd 7,alm&ite7 #d4je ,opal #b4ae ,p]idot #c4dj ,qu>tz 7,ame?y/1 common topaz7 #b4ff ,sp9el 7,rubicelle1 ,balas ruby7 #c4fj ,spodum5e 7,kunzite7 #c4ah ,topaz 7preci\s7 #c4ec ,t\rmal9e #c4aj ,turquoise #b4hb ,zircon1 light] v>iety #d4bj heavi] v>iety #d4fi ,= a m complete & sci5tific discussion ( specific gravity det]m9ation see ,gem-,/ones1 by ,g4 ,f4 ,h]b]t-,smi?1 ,*apt] ,,viii41 pp4 #fc-gg2 or see1 ,a ,h&book ( ,preci\s ,/ones1 by ,m4 ,d4 ,ro?s*ild1 pp4 #ba-bg1 = an excell5t acc\nt ) illu/rations2 or see any physics text-book4 ,,lesson ,,vi ,,specific ,,gravity ,,det]m9ations ,,weigh+ ,a ,,gem ,,9 ,,wat]4 ,9 ! previ\s lesson x 0 se5 t ! id5tity ( a preci\s /one may be f\nd by det]m9+ its specific gravity1 :i* is a numb] t tells h[ mu* heavi] ! mat]ial is ?an a l volume ( wat]4 ,x 0 n expla9$1 h[ev]1 h[ "o w\ld proce$ to get ! specific gravity ( a /one too l>ge to g 9 ! neck ( a specific gravity bottle4 ,9 ! latt] case we resort to ano!r me?od ( f9d+ h[ mu* a l volume ( wat] weighs4 ,if ! /one1 in/ead ( be+ dropp$ into a p]fectly full bottle ( wat] 7:i* !n ov]fl[s71 be dropp$ into a p>tly fill$ glass or small beak] ( wat]1 j z mu* wat] w be displac$ z ?\gh ! vessel 7 full1 & x w be displac$ upw>d z be=e1 = lack ( any o!r place to g4 ,consequ5tly its weight w t5d to buoy up or float ! /one by try+ to get back "u x1 & ! /one :5 9 wat] w weigh less ?an :5 9 air4 ,anyone :o has ev] pull$ up a small an*or :5 out fi%+ f a boat w recognize at once t ?is is ! case1 & t z ! an*or em]ges f ! wat] x seems to sudd5ly gr[ heavi]4 ,n only does ! /one weigh less :5 9 ! wat]1 b x weighs exactly z mu* less z ! weight ( ! wat] t 0 displac$ by ! /one 7:i* has a volume equal to ! volume ( ! /one74 ,if we weigh a /one fir/ 9 ! air1 z usual1 & !n 9 wat] 7:]e x weighs less71 & !n subtract ! weight 9 wat] f ! weight 9 air we w h ! loss ( weight 9 wat]1 & ?is equals ! weight ( an equal volume ( wat]1 :i* is precisely :at we got by our bottle me?od4 ,we n[ ne$ only divide ! weight 9 air by ! loss ( weight 9 wat]1 & we %all h ! specific gravity ( ! /one4 ,illu/ration3 ,,fig4 #f4 ,to actually weigh ! /one 9 wat] we mu/ use a f9e wire to support ! /one4 ,we mu/ fir/ f9d h[ mu* ?is wire itself weighs 7:5 atta*$ by a small loop to ! hook t supports ! balance pan & trail+ p>tly 9 ! wat]1 z w be ! case :5 weigh+ ! /one 9 wat]74 ,?is weight ( ! wire mu/ ( c\rse be d$uct$ to get ! true weight ( ! /one 9 wat]4 ,! beak] ( wat] is be/ support$ by a small table t /&s ov] ! balance pan4 ,"o c easily be made out ( ! pieces ( a cig> box4 7,see ,fig4 #f47 ,! wire t is to support ! /one %\ld h a spiral at ! bottom 9 :i* to lay ! gem1 & ?is %\ld be s plac$ t ! latt] w be completely subm]g$ at all times1 b n t\*+ bottom or sides ( ! beak]4 ,example ( data1 & calculation1 :5 gett+ specific gravity by ! me?od ( weigh+ 9 wat]3 ,weight ( /one #d4jb c>ats ----------- ,weight ( /one 7plus wire7 9 wat] #c4cb c>ats ,weight ( wire 4#cj c>at ----------- ,true weight ( /one 9 wat] #c4jb c>ats ----------- ,loss ( weight 9 wat] #a4jj c>at ,weight ( /one #d4jb ,specific gravity --------------- ---- #d4jb ,loss 9 wat] #a4jj ,"h ! specific gravity1 #d4jb w\ld indicate "s corundum gem 7ruby or sapphire71 & ! o!r *>act]s w\ld indicate at once :i* x 04 ,! /ud5t :o means to ma/] ! use ( ! two me?ods giv5 9 ,lessons ,v4 & ,,vi4 %\ld proce$ to practice !m ) /ones ( kn[n specific gravities until he c at lea/ get ! correct result to ! fir/ decimal place4 ,x is n to be expect$ t accurate results c be _h 9 ! second decimal place1 ) ! balances usually available to jewel]s4 ,:5 ! le>n] c det]m9e specific gravities ) "s c]ta9ty he %\ld !n try unkn[n gems4 ,! specific gravity me?od is ( especial value 9 di/+ui%+ betwe5 ! v>i\s colorless /ones1 z1 = example1 qu>tz cry/al1 true :ite topaz1 :ite sapphire1 :ite or colorless b]yl1 etc4 ,^! are all d\bly refractive1 h no color1 & h5ce no di*roism1 & unless "o has a refractomet] to get ! refractive index1 !y are difficult to di/+ui%4 ,! specific gravities are v diff]5t1 h[ev]1 & readily s]ve to di/+ui% !m4 ,x %\ld be add$ t ! syn!tic /ones %[ ! same specific gravities z _! natural c\nt]p>ts1 s t ?is te/ does n s]ve to detect !m4 ,:]e _m gems are to be h&l$ & sep>at$ by specific gravity det]m9ations1 p]haps ! be/ way to d s is to h sev]al liquids ( kn[n specific gravity & to see :at /ones w float & :at ones w s9k 9 ! liquids4 ,me?yl5e iodide is a heavy liquid 7sp4 g4 #c4cb71 on :i* a qu>tz-topaz1 = example1 sp4 g4 #b4ff1 w\ld float1 b a true topaz1 sp4 g4 #c4ec1 w\ld s9k 9 x4 ,by dilut+ me?yl5e iodide ) b5zol 7sp4 g4 #j4hh7 any specific gravity t is desir$ may be _h 7betwe5 ! two limits #j4hh & #c4cb74 ,specim5s ( kn[n specific gravity are us$ ) su* liquids & _! behavior 7z to :e!r !y s9k or float1 or rema9 susp5d$ 9 ! liquid17 indicates ! specific gravity ( ! liquid4 ,an unkn[n /one may !n be us$ & its behavior not$ & comp>$ ) t ( a kn[n specim51 :]eby "o c easily f9d out :e!r ! unkn[n is heavi] or light] ?an ! kn[n sample4 ,an excell5t acc\nt ( ! detail ( ?is me?od is giv5 9 ,g4 ,f4 ,h]b]t-,smi?'s ,gem-,/ones1 pages #fd-ga1 ( ,*apt] ,,viii41 & v>i\s liquids are !re recomm5d$4 ,x is d\btful if ! practical gem deal] w\ld f9d ^! me?ods necess>y 9 mo/ cases4 ,:]e l>ge numb]s ( _m diff]5t unkn[n gems h to be det]m9$ x w\ld pay to prep>e1 & /&>dize1 & use su* solutions4 ,,lesson ,,vii ,,lu/] ,,& ,,o!r ,,reflection ,,effects ,by ! t]m lu/] we ref] to ! mann] & degree 9 :i* light is reflect$ f ! surface ( a mat]ial4 ,surfaces ( ! same mat]ial1 b ( v>y+ degrees ( smoo?ness w\ld1 ( c\rse1 v>y 9 ! vividness ( _! lu/]1 b ! type ( v>iation t may be made use ( to help di/+ui% gems1 dep5ds ^u ! "* ( ! mat]ial m ?an ^u ! degree ( smoo?ness ( its surface4 ,j z silk has s typical a lu/] t we speak ( x z silky lu/]1 & j z pe>l has a pe>ly lu/]1 s c]ta9 gems h peculi> & *>act]i/ic lu/]4 ,! diamond gives u a good example4 ,mo/ diamond deal]s di/+ui% betwe5 real & imitation diamonds at a glance by ! "* ( ! lu/]4 ,t is ! *ief1 & p]haps ! only prop]ty1 t !y rely ^u = decid+ ! g5u95ess ( a diamond1 & !y are fairly safe 9 s do+1 =1 ) ! exception ( c]ta9 artificially decoloriz$ zircons1 no gem /one is likely to deceive "o :o is famili> ) ! lu/] ( ! diamond4 ,x is n to be d5i$ t a f9e :ite zircon1 :5 f9ely cut1 may deceive ev5 "o :o is famili> ) diamonds4 ,! au?or has fool$ _m diamond exp]ts ) an especially f9e zircon1 = ! lu/] ( zircon does approa*1 ?\gh x h>dly equals1 t ( ! diamond4 ,r\gh zircons are frequ5tly mi/ak5 = diamonds by diamond prospectors1 & ev5 by pick]s 9 ! m9es1 s t "s c>e %\ld be ex]cis$ 9 any suspici\s case1 & "o %\ld n !n rely solely on ! lu/]4 ,h[ev]1 9 mo/ cases 9 ! trade !re is almo/ no *ance ( ! unexpect$ pres5ce ( a zircon & ! lu/] te/ is usually suffici5t to di/+ui% ! diamond4 7,zircons are /rongly d\bly refractive1 z 0 said 9 ,lesson ,,iii4 on ,d\ble ,refraction1 & ) a l5s ! d\bl+ ( ! back l9es may be se547 ,,adamant9e ,,lu/]4 ,! lu/] ( a diamond is call$ adamant9e 7! adjective uses ! ,greek "n = ! /one itself74 ,x is ke5 & cold & glitt]+1 hav+ a metallic sugge/ion4 ,a v l>ge p] c5t4 ( ! light t falls ^u ! surface ( a diamond at any l[ angle is reflect$1 h5ce ! ke5ness ( its lu/]4 ,if a diamond & "s o!r :ite /one1 say a :ite sapphire1 are held s z to reflect at ! same "t images ( an inc&esc5t light into ! eye ( ! obs]v]1 su* a direct comp>ison w s]ve to %[ t mu* m light comes to ! eye f ! diamond surface ?an f ! sapphire surface4 ,! image ( ! light filam5t1 z se5 f ! diamond1 is mu* ke5] ?an z se5 f ! sapphire4 ,! same disp>ity w\ld exi/ betwe5 ! diamond & almo/ any o!r /one4 ,zircon comes ne>e/ to hav+ adamant9e lu/] ( any ( ! o!r gems4 ,! gre5 g>net t is call$ oliv9e 9 ! trade also approa*es diamond 9 lu/]1 h5ce ! "n demantoid1 or diamond l1 sometimes appli$ to x4 ,,vitre\s ,,lu/]4 ,! o!r /ones ne>ly all h :at is call$ vitre\s lu/] 7lit]ally1 glass l71 yet ow+ to diff]5ce ( h>dness1 & consequ5t m9ute diff]5ces 9 f95ess ( surface f9i%1 ! ke5ness ( ?is vitre\s lu/] v>ies slightly 9 diff]5t /ones1 & a tra9$ eye c obta9 clues to ! id5tity ( c]ta9 /ones by means ( a consid]ation ( ! lu/]4 ,g>nets1 = example1 be+ h>d] ?an glass1 take a ke5] poli%1 & a glance at a d\blet 7( :i* ! h>d top is usually g>net & ! base ( glass7 w %[ t ! light is bett] reflect$ f ! g>net "p ( ! top slope ?an f ! glass "p4 ,?is use ( lu/] af=ds ! quicke/ & sure/ means ( detect+ a d\blet4 ,"o c ev5 tell a d\blet inside a %[ w9d[1 al?\gh ! obs]v] be outside on ! sidewalk1 by mov+ to a position su* t a reflection f ! top slope ( ! /one is to be _h4 ,:5 a d\blet has a complete g>net top no su* direct comp>ison c be _h1 b by view+ fir/ ! top lu/]1 & !n ! back lu/]1 9 rapid succession1 "o c tell :e!r or n ! /one is a d\blet4 ,,oily ,,lu/]4 ,c]ta9 /ones1 notably ! p]idot 7or *rysolite7 & ! hessonite 7or c9namon /one71 h an oily lu/]4 ,?is is possibly due to reflection ( light t has p5etrat$ ! surface slightly & !n be5 reflect$ f di/urb$ lay]s b5ea? ! surface4 ,at any rate1 ! diff]5ce 9 lu/] may be made use ( by ^? :o h tra9$ _! eyes to appreciate x4 ,mu* practice w be ne$$ be=e "o c expect to tell at a glance :5 he has a p]idot 7or *rysolite7 by ! lu/] alone1 b x w pay to sp5d "s sp>e "t 9 /udy+ ! lu/] ( ! v>i\s /ones4 ,a true1 or preci\s topaz1 = example1 may be comp>$ ) a yell[ qu>tz-topaz1 & ow+ to ! great] h>dness ( ! true topaz1 x w be not$ t x has a slightly ke5] lu/] ?an ! o!r /one1 al?\gh bo? h vitre\s lu/]4 ,simil>ly ! corundum gems 7ruby & sapphire71 be+ ev5 h>d] ?an true topaz1 take a spl5did surface f9i% & h a v ke5 vitre\s lu/]4 ,turquoise has a dull waxy lu/]1 due to its slight h>dness4 ,mala*ite1 al?\gh s(t1 has1 p]haps because ( its opacity1 a ke5 & sometimes almo/ metallic lu/]4 ,"o may note ! lu/] rapidly1 )\t app>atus & )\t damage to ! /one4 ,we ?us h a te/ :i*1 :ile x is n conclusive except 9 a v few cases1 w supplem5t & s]ve to confirm o!r te/s1 or p]haps1 if us$ at fir/1 w sugge/ :at o!r te/s to apply4 ,ano!r optical effect t s]ves to di/+ui% "s /ones dep5ds ^u ! reflection ( light f )9 ! mat]ial due to a c]ta9 lack ( homog5eity 9 ! sub/ance4 ,,cause ,,( ,,color ,,9 ,,! ,,opal4 ,?us ! opal is di/+ui%$ by ! prismatic colors t em]ge f x ow+ to ! effect ( ?9 lay]s ( mat]ial ( slightly diff]5t d5sity1 & h5ce ( diff]5t refractive index f ! re/ ( ! mat]ial4 ,^! ?9 films act mu* z d soap-bubble films1 to int]f]e ) light ( c]ta9 wave l5g?s1 b to reflect c]ta9 o!r wave l5g?s & h5ce c]ta9 colors4 ,aga91 9 "s sapphires & rubies are f\nd m9ute1 probably holl[1 tube-l cavities1 arrang$ 9 ?ree sets 9 ! same positions z ! transv]se axes ( ! hexagonal cry/al4 ,! surfaces ( ^! tubes reflect light s z to produce a six-po9t$ /> effect1 especially :5 ! /one is prop]ly cut to a high1 r\nd cabo*on =m1 ^: base is p>allel to ! successive lay]s ( tubes4 ,,/>/ones1 ,,moon/ones1 ,,cat',s-,,eyes4 ,9 ! moon/one we h ano!r sort ( effect1 ?is "t due to ! pres5ce ( ho/s ( small tw9 cry/al lay]s t reflect light s z to produce a sort ( moonlight-on-!-wat] appe>ance )9 ! /one :5 ! latt] is prop]ly cut1 ) ! lay]s ( tw9 cry/als p>allel to its base4 ,ceylon-cut moon/ones are frequ5tly cut to save weight1 & may h to be recut to prop]ly place ! lay]s s t ! effect may be se5 equally ov] all p>ts ( ! /one1 z set4 ,cat's-eye & tig]'s-eye owe _! peculi> appe>ance to ! pres5ce1 )9 !m1 ( _m f9e1 p>allel1 silky fib]s4 ,! qu>tz cat's-eye 0 probably once an asbe/os-l m9]al1 ^: s(t fib]s 7 replac$ by qu>tz 9 solution1 & ! latt]1 :ile giv+ its h>dness to ! new m9]al1 also took up ! fibr\s arrangem5t ( ! orig9al mat]ial4 ,! true *rysob]yl cat's-eye also has a some:at simil> fibr\s or p]haps tubul> /ructure4 ,su* /ones1 :5 cut en cabo*on1 %[ a ?9 %>p l9e ( light runn+ across ! c5t] ( ! /one 7:5 prop]ly cut ) ! base p>allel to ! fib]s74 ,?is is due to reflection ( light f ! surfaces ( ! p>allel fib]s4 ,! l9e ( light runs p]p5dicul>ly to ! fib]s4 ,9 ^! cases 7opals1 />/ones1 moon/ones1 & cat's-eyes7 ! individual /one is usually easily di/+ui%$ f o!r k9ds ( /ones by its peculi> behavior t[>ds light4 ,h[ev]1 x mu/ be rememb]$ t o!r species ?an corundum furni% />/ones 7ame?y/ & o!r v>ieties ( qu>tz1 = example71 s t x does n foll[ t any />/one is a corundum gem4 ,also ! m valuable *rysob]yl cat's-eye may be confus$ ) ! *eap] qu>tz cat's-eye unless "o is well acqua9t$ ) ! respective appe>ances ( ! two v>ieties4 ,:5ev] !re is any d\bt o!r te/s %\ld be appli$4 ,= fur!r acc\nt ( lu/] & o!r types ( reflection effects see ,gem-,/ones1 by ,g4 ,f4 ,h]b]t-,smi?1 ,*apt] ,v41 pp4 #cg-ci1 or ,a ,h&book ( ,preci\s ,/ones1 ,m4 ,d4 ,ro?s*ild1 pp4 #ag1 #ah4 ,,lesson ,,viii ,,h>dness ,ano!r prop]ty by means ( :i* "o may di/+ui% ! v>i\s gems f ea* o!r is h>dness4 ,by h>dness is meant ! ability to resi/ scrat*+4 ,! t]m h>dness %\ld n be tak5 to include t\ghness1 yet x is frequ5tly s und]/ood by ! public4 ,mo/ h>d /ones are m or less brittle & w\ld %att] if /ruck a %>p bl[4 ,o!r h>d /ones h a pron\nc$ cleavage & split easily 9 c]ta9 directions4 ,true h>dness1 !n1 implies m]ely ! ability to resi/ abrasion 7i4 e41 scrat*+74 ,n[1 n only is h>dness v necess>y 9 a preci\s /one 9 ord] t x may receive & keep a f9e poli%1 b ! degree 9 :i* x possesses h>dness z comp>$ ) o!r mat]ials ( kn[n h>dness may be made use ( 9 id5tify+ x4 ,no scale ( absolute h>dness has ev] come into g5]al use1 b ! m9]alogi/ ,mohs _m ye>s ago propos$ ! foll[+ relative scale1 :i* has be5 us$ v l>gely3 ,,mohs',s ,,scale ,,( ,,h>dness4 ,diamond1 ! h>de/ ( all gems1 0 rat$ z #aj by ,mohs4 ,?is rat+ 0 purely arbitr>y4 ,mohs might h call$ x #ajj or #a ) equal reason4 ,x 0 m]ely 9 ord] to repres5t ! diff]5t degrees ( h>dness by numb]s1 t he pick$ out ! numb] #aj to assign to diamonds4 ,sapphire 7& ruby7 ,mohs call$ #i1 z be+ next to diamond 9 h>dness4 ,true topaz 7preci\s topaz7 he call$ #h4 ,qu>tz 7ame?y/ & qu>tz topaz7 0 giv5 ! numb] #g4 ,feldsp> 7moon/one7 0 rat$ #f1 ! m9]al apatite #e1 fluorsp> #d1 calcite #c1 gypsum #b1 & talc #a4 ,x may be said "h t any m9]al 9 ?is s]ies1 t is ( high] numb] ?an any o!r1 w scrat* ! o!r4 ,?us diamond 7#aj7 w scrat* all ! o!rs1 sapphire 7#i7 w scrat* any b diamond1 topaz 7#h7 w scrat* any b diamond & sapphire1 & s on4 ,x mu/ n be ?\ght t !re is any regul>ity 9 ! degrees ( h>dness z express$ by ^! numb]s4 ,! int]vals 9 h>dness are by no means equal to ! diff]5ces 9 numb]4 ,?us ! int]val betwe5 diamond & sapphire1 al?\gh giv5 b "o numb] ( diff]5ce1 is probably great] ?an t betwe5 sapphire 7#i7 & talc 7#a74 ,! numb]s ?us m]ely give u an ord] ( h>dness4 ,_m gem m9]als are1 ( c\rse1 miss+ f ?is li/1 & mo/ ( ! m9]als f #e d[n to #a are n gem m9]als at all4 ,few gem mat]ials are ( less h>dness ?an #g1 = any m9]al less h>d ?an qu>tz 7#g7 w inevitably be worn & dull$ 9 "t by ! ord9>y road du/1 :i* conta9s mu* p[d]$ qu>tz4 ,9 te/+ a gem = h>dness ! problem consi/s 9 f9d+ out :i* ( ! above m9]als is mo/ ne>ly equal 9 h>dness to ! unkn[n /one4 ,any gem t 0 approximately equal 9 h>dness to a true topaz 7#h7 w\ld also be said to be ( h>dness #h4 ,?us sp9el is ( ab\t ! same h>dness z topaz & h5ce is usually rat$ z #h 9 h>dness4 ,simil>ly opal1 moon/one1 & turquoise are ( ab\t ! same h>dness z feldsp> & are all rat$ #f4 ,frequ5tly /ones w be f\nd t 9 h>dness are betwe5 "s two ( ,mohs's m9]als4 ,9 t case we add "o half to ! numb] ( ! s(t] m9]al2 ?us1 p]idot1 b5itoite1 & jade 7nephrite7 are all s(t] ?an qu>tz 7#g7 b h>d] ?an feldsp> 7#f72 h5ce we say !y are #f-a_/b 9 h>dness4 ,b]yl 7aquam>9e & em]ald71 g>net 7alm&9e71 & zircon are rat$ #g-a_/b 9 h>dness1 be+ s(t] ?an true topaz b h>d] ?an qu>tz4 ,a table ( ! h>dness ( mo/ ( ! commonly kn[n gem-/ones foll[s ?is lesson4 ,hav+ n[ an idea ( :at h>dness means & h[ x is express$1 we mu/ next inquire h[ "o may make use ( x 9 id5tify+ unkn[n gems4 ,,h[ ,,to ,,apply ,,! ,,h>dness ,,te/4 ,9 ! fir/ place1 x is necess>y to caution ! beg9n] aga9/ damag+ a f9e gem by attempt+ to te/ its h>dness 9 any b ! mo/ c>eful mann]4 ,! "t-honor$ file te/ is really a h>dness te/ & s]ves nicely to di/+ui% g5u9e gems1 ( h>dness #g or above1 f glass imitations4 ,a well-h>d5$ /eel file is ( n q h>dness #g1 & glass ( v>i\s types :ile v>y+ some:at av]ages betwe5 #e & #f4 ,h5ce1 glass imitations are easily attack$ by a file4 ,to make ! file te/ use only a v f9e file & apply x ) a light b firm pressure l5g?wise along ! girdle 7edge7 ( ! unset /one4 ,if damage results x w !n be almo/ unnoticeable4 ,le>n to "k ! feel ( ! file z x takes hold ( a sub/ance s(t] ?an itself4 ,also le>n ! s\nd4 ,if appli$ to a h>d /one a file w slip on x1 z a skate slips on ice4 ,x w n take hold z ^u a s(t] sub/ance4 ,if ! /one is set1 press a %>p corn] ( a brok5-end$ file g5tly aga9/ a back facet1 pref]ably high up t[>d ! girdle1 :]e any damage w n be visible f ! front1 & move ! file v slightly along ! surface1 not+ by ! feel :e!r or n x takes hold & also look+ ) a l5s to see if a scrat* has be5 made4 ,d n mi/ake a l9e ( /eel1 left on a slightly r\gh surface1 = a true scrat*4 ,frequ5tly on an unpoli%$ girdle ( real gem mat]ial ! file w leave a /reak ( /eel4 ,simil>ly :5 us+ te/ m9]als 9 accordance ) :at foll[s d n mi/ake a /reak ( p[d] f ! yield+ te/ mat]ial1 = a true scrat* 9 ! mat]ial be+ te/$4 ,! safe way is to wipe ! spot ?us remov+ any p[d]4 ,a true scrat* w1 ( c\rse1 p]si/4 ,a d\blet1 be+ usually con/ruct$ ( a g>net top & a glass back1 may resi/ a file at ! girdle if ! g>net top cov]s ! /one to ! girdle1 z is sometimes ! case1 especially 9 ! small] sizes4 ,9 ?is case ! back mu/ be te/$4 ,"o %\ld nev] pass a file rudely across ! corn]s or edges ( ! facets on any /one t may be g5u9e1 z su* treatm5t really am\nts to a s]ies ( light hamm] bl[s1 & ! brittl5ess ( mo/ gem /ones w\ld cause !m to yield1 irrespective ( _! h>dness4 ,x %\ld be rememb]$ t "s g5u9e /ones are s(t] ?an a file1 s t x w n d to reject z wor?less any mat]ial t is attack$ by a file4 ,lapis lazuli 7#e71 sph5e 7#e71 opal 7#f71 moon/one 7#f71 amazonite 7#f71 turquoise 7#f71 p]idot 7#f-a_/b71 demantoid g>net 7#f-a_/b7 7! oliv9e ( ! trade71 & jade 7nephrite7 7#f-a_/b71 are all m or less attack$ by a file4 ,,table ,,( ,,h>dness ,,( ,,! ,,pr9cipal ,,gem-,,/ones #aj4 ,diamond4 #i-a_/b4 7,c>borundum47 #i4 ,sapphire & ruby 7also all ! color v>ieties ( sapphire74 #h-a_/b4 ,*rysob]yl 7alex&rite74 #h4 ,true topaz & sp9el 7rubicelle1 balas ruby74 #g-a_/b4 ,em]ald1 aquam>9e1 b]yl1 ,morganite1 zircon 7jac9? & true hyac9? & j>goon71 alm&9e g>net4 #g-a_/d4 ,pyrope g>net 7,arizona ruby1 cape ruby71 hessonite g>net 7c9namon /one71 t\rmal9e 7v>i\s colors v>y f #g to #g-a_/b71 kunzite 7#g74 #g4 ,ame?y/1 v>i\s qu>tz gems1 qu>tz topaz1 jade 7jadeite74 #f-a_/b4 ,p]idot 7*rysolite71 demantoid g>net 7oliv9e71 jade 7nephrite74 #f4 ,opal1 moon/one1 turquoise4 #e4 ,lapis lazuli4 ,,lesson ,,ix ,,h>dness--,cont9u$ ,,m9]als ,,us$ ,,9 ,,te/+ ,,h>dness4 ,= te/+ /ones t are h>d] ?an a file ! /ud5t %\ld provide himself ) ! foll[+ set ( mat]ials3 #a4 ,a small cry/al ( c>borundum4 7,mo/ h>dw>e /ores h specim5 cry/als z attractive adv]tisem5ts ( c>borundum z an abrasive mat]ial1 or ! ,c>borundum ,co41 ,niag>a ,falls1 ,n4 ,y41 w supply "o47 #b4 ,a small cry/al ( sapphire 7n ( gem quality1 b x %\ld be transp>5t & compact4 ,a pale or colorless ,montana sapphire c be _h = a few c5ts ( any m9]al deal]74 #c4 ,a small true topaz cry/al4 7,! pure :ite topaz ( ,?omas ,m\nta91 ,utah1 is excell5t2 or :ite topaz f ,brazil or ,japan or ,mexico or ,colorado w d4 ,any m9]al h\se c furni% small cry/als = a few c5ts :5 n ( specially f9e cry/allization47 #d4 ,a small qu>tz cry/al4 7,?is may be ei!r ame?y/ or qu>tz-topaz or ! common colorless v>iety4 ,! f9e1 %>p1 colorless cry/als f ,h]kim] ,c\nty1 ,n4 ,y41 are excell5t4 ,^! are v inexp5sive47 #e4 ,a fragm5t ( a cry/al ( feldsp>4 7,common or?oclase feldsp>1 :i* is frequ5tly ( a br[ni% p9k or fle% color1 w d47 ,^! five te/ /ones repres5t ! foll[+ degrees ( h>dness3 #a4 ,c>borundum is h>d] ?an any gem mat]ial b diamond4 ,x w scrat* sapphire & ruby1 :i* are rat$ #i 9 h>dness1 h5ce we may call c>borundum #i-a_/b if we wi%4 ,x is1 h[ev]1 v mu* s(t] ?an diamond1 & ! latt] w scrat* x ^u ! slighte/ pressure4 #b4 ,sapphire1 ( h>dness #i1 scrat*+ any gem mat]ial except diamond4 #c4 ,true topaz1 ( h>dness #h4 ,x is scrat*$ by sapphire 7&1 ( c\rse1 ruby71 also by *rysob]yl 7:i* is h5ce rat$ #h-a_/b71 b scrat*es mo/ o!r /ones4 ,sp9el 7:i* is also rat$ z #h 9 h>dness7 is really a bit h>d] ?an topaz4 #d4 ,qu>tz1 ( h>dness #g1 & scrat*$ by all ! previ\s /ones b scrat*+ ^? t 7 li/$ above z ( less h>dness ?an a file4 #e4 ,feldsp>1 ( h>dness #f1 h5ce slightly s(t] ?an a file & yield+ to x1 b scrat*+ ! /ones likewise rat$ z #f :5 appli$ =cibly to !m4 ,also scrat*+ /ones rat$ z less ?an #f on slight pressure4 ,we mu/ next consid] h[ ^! m9]als may be safely us$ ^u gem mat]ial4 ,obvi\sly x w\ld be f> saf] to use !m ^u r\gh gem mat]ial ?an ^u cut /ones4 ,h[ev]1 ) c>e & "s little skill1 "o may make h>dness te/s )\t p>ticul> dang] to f9e cut mat]ial4 ,! way to proce$ is to apply ! cut /one 7pref]ably its girdle1 or if t is s set z n to be available1 a corn] :]e sev]al facets meet7 g5tly to ! flat surface ( "o ( ! s(t] te/ /ones1 draw+ x lightly along ! surface & not+ ! feel & look+ to see if a scrat* results4 ,if ! te/ /one is scrat*$ try ! next h>d] te/ /one simil>ly4 ,d n attempt to use ! te/ /one ^u any valuable cut /one4 ,proce$ z above until ! gem meets a te/ /one t x does n attack4 ,its h>dness is !n probably equal to ! latt] & p]haps if press$ =cibly aga9/ x a slight scrat* w\ld result1 b x is n advisable to resort to heavy pressure4 ,a light t\* %\ld be cultivat$ 9 ?is "w4 ,hav+ n[ an indication z to ! h>dness ( ! unkn[n gem look up 9 ! table ( ! previ\s lesson ^? gems ( simil> h>dness & !n by ! use ( "s ( ! te/s already giv5 decide :i* ( ! /ones ( t degree ( h>dness y h4 ,nev] rely ^u a s+le te/ 9 id5tify+ a gem4 ,= fur!r /udy ( h>dness & its use 9 te/+ gems see ,gem-,/ones1 ,g4 ,f4 ,h]b]t-,smi?1 ,*ap4 ,,ix41 pp4 #gh-ha1 & table on p4 #cje2 or see ,a ,h&book ( ,preci\s ,/ones1 ,ro?s*ild1 pp4 #ai1 #bj1 #ba4 ,,lesson ,x ,,disp]sion ,ano!r prop]ty :i* may be made use ( 9 decid+ ! id5tity ( c]ta9 gems is t call$ disp]sion4 ,we h se5 9 ,lesson ,,ii4 t light 9 ent]+ a /one f ! air *anges its pa? 7refraction71 & 9 ,lesson ,,iii4 x 0 expla9$ t _m m9]als cause light t ent]s !m1 to divide & proce$ along two diff]5t pa?s 7d\ble refraction74 ,n[ x is fur!r true t light ( ! v>i\s colors 7r$1 orange1 yell[1 gre51 blue1 & violet7 is refract$ v>i\sly--! violet be+ b5t mo/ %>ply1 ! r$ lea/1 & ! o!r colors to int]m$iate degrees4 ,! cut 7,fig4 #g7 repres5ts r\ghly & 9 an exagg]at$ mann] ! effect we are discuss+4 ,illu/ration3 ,,fig4 #g4 ,n[ 9 a cut /one ?is sep>ation ( light ( diff]5t colors1 or disp]sion ( light1 z x is call$1 results 9 ! reflection ( ea* ( ! colors sep>ately f ! /eep slop+ back facets ( ! /one4 ,if almo/ any cle>1 colorless facett$ /one is plac$ 9 ! sunlight & a c>d held be=e x to receive ! reflections1 x w be se5 t ra9b[-l reflections appe> on ! c>d4 ,^! spectra1 z !y are call$1 are caus$ by ! disp]sion ( light4 ,) a diamond ! spectra w be v brilliant & ( vivid color+1 & ! r$ w be widely sep>at$ f ! blue4 ,) :ite sapphire or :ite topaz1 or ) rock cry/al 7qu>tz71 ! spectra w be less vivid--!y w appe> 9 pairs 7due to ! d\ble refraction ( ^! m9]als71 & ! r$ & blue w be ne> toge!r 7i4 e41 ! spectra w be %ort74 ,?is %ortness 9 ! latt] cases is due to ! small disp]sive p[] ( ! ?ree m9]als m5tion$4 ,pa/e 7lead glass7 gives fairly vivid spectra1 & !y are s+le l ^? f diamond1 z glass is s+ly refract+4 ,! disp]sion ( ! heavy lead glass approa*es t ( diamond4 ,! decoloriz$ zircon 7j>goon7 has a disp]sion well up t[>d t ( diamond & gives fairly vivid spectra on a c>d1 b !y are d\ble1 z zircon is d\bly refract+4 ,sph5e 7a gem r>ely se5 9 ! trade7 & ! demantoid g>net 7a gre5 gem (t5 call$ oliv9e 9 ! trade7 bo? h v high disp]sive p[]1 exce$+ ! diamond 9 ?is respect4 ,z !y are bo? color$ /ones 7sph5e is usually yell[i%1 sometimes gre5i% or br[n71 ! vividness ( _! color-play is mu* dim9i%$ by absorption ( light )9 !m4 ,s also ! color-play ( a deeply color$ fancy diamond is dim9i%$ by absorption4 ,,disp]sion ,,z ,a ,,te/ ,,( ,,! ,,id5tity ,,( ,a ,,gem4 ,we may n[ consid] h[ an acqua9tance ) ! disp]sive p[]s ( ! v>i\s /ones c be us$ 9 di/+ui%+ !m4 ,if a /one has high disp]sive p[] x w exhibit fire1 z x is call$--i4 e41 ! v>i\s colors w be s widely sep>at$ )9 ! /one1 & h5ce reflect$ out s widely sep>at$1 t !y w fall on ! eye 7z on ! c>d above7 9 sep>ate lay]s1 & vivid fla%es ( r$ or yell[ or o!r colors w be se54 ,su* /ones z ! :ite sapphire 7& o!rs ( small disp]sion71 h[ev]1 :ile sep>at+ ! v>i\s colors appreciably z se5 reflect$ on a c>d1 d n suffici5tly sep>ate !m to produce ! fire effect :5 ! light falls on ! eye4 ,?is is because ! v>i\s colors1 be+ v ne> toge!r 9 ?is case1 cross ! eye s rapidly1 :5 ! /one is mov$1 t !y bl5d _! effect & ! eye reg>ds ! light t ?us falls ^u x z :ite4 ,we h "h a ready means ( di/+ui%+ ! diamond f mo/ o!r colorless gems4 ,! tra9$ diamond exp]t relies 7probably unconsci\sly7 ^u ! disp]sive effect 7or fire7 ne>ly z mu* z ^u ! adamant9e lu/]1 9 tell+ at a glance :e!r a /one is or is n a diamond4 ,( all colorless /ones1 ! only "o likely to mislead ! exp]t 9 ?is respect is ! :it5$ zircon 7j>goon71 :i* has almo/ adamant9e lu/] & 9 addition ne>ly z high disp]sive p[] z diamond4 ,h[ev]1 zircon is d\bly refract+ 7/rongly s71 & ! division ( ! spectra :i* results 7ea* facet produc+ two in/ead ( only "o7 weak5s ! fire s t ev5 ! be/ zircon is a bit sleepy z comp>$ ) ev5 an ord9>y diamond4 ,9 addition to provid+ a ready means ( id5tify+ ! diamond1 a high degree ( disp]sion 9 a /one ( pron\nc$ color w\ld lead "o to consid] sph5e1 demantoid g>net 7if gre571 & zircon 7:i* might be r$di%1 yell[i%1 br[n1 or ( o!r colors71 & if ! /one did n agree ) ^! 9 its o!r prop]ties "o %\ld suspect glass4 ,a good way to note ! degree ( disp]sion1 aside f ! sunlight-c>d me?od1 is to look at ! /one f ! back :ile hold+ x up to ! light 7daylight74 ,/ones ( high disp]sive p[] w display vivid color play 9 ?is position4 ,glass imitations ( rubies1 em]alds1 ame?y/s1 etc41 w display altoge!r too mu* disp]sion = ! natural gems4 ,9 ,*ap4 ,,iii41 p4 #bj1 ( ,g4 ,f4 ,h]b]t-,smi?'s ,gem-,/ones1 a brief acc\nt ( disp]sion is giv54 ,college text-books on physics also treat ( x1 & ! latt] give an acc\nt ( h[ disp]sion is measur$ & :at is meant by a coeffici5t ( disp]sion4 ,mo/ gem books say little ab\t x1 b z we h se5 above1 a k ( ! matt] c1 :5 supplem5t$ by o!r te/s1 be appli$ practically 9 di/+ui%+ gems4 ,,lesson ,,xi ,,color ,9 res]v+ to ! la/ ! prop]ty ( color1 :i* _m deal]s 9 gems use fir/ :5 attempt+ to id5tify a preci\s /one1 ,i h s\ght to po9t out ! fact t a det]m9ation bas$ solely ^u color is v likely to be wrong4 ,s _m m9]al species are f\nd 9 s _m diff]5t colors t to attempt to id5tify any m9]al species by color alone is usually to invite disa/]4 ,! em]ald1 alone among gems1 has1 :5 ( f9e color1 a hue t is n approa*$ by any o!r species4 ,! color ( ! grass 9 ! spr+time fitly describes x4 ,yet ev5 "h ! art ( man has s closely c\nt]feit$ 9 glass ! gre5 ( ! em]ald t "o _c be sure ( 8 /one by color alone4 ,z 0 sugge/$ e>li] 9 ^! lessons1 ! writ] has sev]al times rec5tly _h occasion to condemn z glass imitations /ones = :i* high prices _h be5 paid z g5u9e em]alds1 ^? :o sold !m hav+ reli$ solely ^u a tra9$ eye = color4 ,,confusion ,,( ,,gems ,,due ,,to ,,simil>ity ,,( ,,color4 ,! same t5d5cy to rely ^u color causes _m 9 ! trade to call all yell[ /ones topaz :e!r ! species be corundum 7ori5tal topaz71 true topaz 7preci\s topaz71 citr9e qu>tz 7qu>tz topaz71 heliodor 7yell[ b]yl71 jac9? 7yell[ zircon71 or :at n4 ,simil>ly ! public calls all r$ /ones ruby4 ,?us we h cape ruby & ,arizona ruby 7pyrope g>net71 sp9el ruby 7m prop]ly ruby sp9el71 ,siam ruby 7v d>k r$ corundum71 ,ceylon ruby 7pale p9ki% corundum71 rubellite 7p9k t\rmal9e71 & la/ly ,burmah ruby 7! f9e blood-r$ corundum74 ,:ile x is true t color1 unless skillfully e/imat$ & wisely us$ 9 conjunction ) o!r prop]ties1 is a mo/ unreliable guide1 yet :5 ?us us$1 x becomes a great help & s]ves sometimes to n>r[ d[n ! *ase1 at ! />t1 to a v few species4 ,to ?us make use ( x requires an actual acqua9tance ) ! v>i\s gem mat]ials1 9 _! usual colors & %ades & an eye tra9$ to note & to rememb] m9ute diff]5ces ( t9t & %ade4 ,! sugge/ions :i* foll[ z to usual colors ( m9]al species mu/ !n be us$ only ) discretion & aft] mu* fai?ful /udy ( _m specim5s ( ea* ( ! species4 ,let u beg9 ) ! beg9n+ color ( ! visible spectrum1 r$1 & consid] h[ a close /udy ( %ades ( r$ c help 9 di/+ui%+ ! v>i\s r$ /ones f ea* o!r4 ,9 ! fir/ place we w inquire :at m9]al species are likely to furni% u ) r$ /ones4 ,omitt+ a numb] ( r>e m9]als1 we h 7#a7 corundum ruby1 7#b7 g>net ( v>i\s types1 7#c7 zircon1 7#d7 sp9el1 7#e7 t\rmal9e4 ,^! five m9]als are ab\t ! only common species :i* give u an out-&-out r$ /one4 ,let u n[ consid] ! di/9ctions betwe5 ! r$s ( ^! diff]5t species4 ,! r$ ( ! ruby1 :e!r d>k 7,siam type71 blood r$ 7,burmah type71 or pale 7,ceylon71 is m pleas+ usually ?an ! r$ ( any ( ! o!r species4 ,view$ f ! back ( ! /one 7by transmitt$ light7 x is /ill pleas+4 ,x may be purpli%1 b is seldom orange r$4 ,also1 ow+ to ! di*roism ( ! ruby ! r$ is v>iable accord+ to ! *ang+ position ( ! /one4 ,x !re=e has a c]ta9 life & v>iety n se5 9 any ( ! o!rs except p]haps 9 r$ t\rmal9e1 :i*1 h[ev]1 does n approa* ruby 9 f95ess ( r$ color4 ,,r$ ,,/ones ,,( ,,simil> ,,%ades4 ,! g>net1 on ! o!r h&1 :5 ( fire-r$ hue1 is d>k] ?an any b ! ,siam ruby4 ,x is also m incl9$ to orange r$ or br[ni% r$--& ! latt] is especially true :5 ! /one is se5 aga9/ ! light 7by transmitt$ light74 ,its color !n resembles t ( a solution ( iron su* z is giv5 z m$ic9e4 ,! s-call$ alm&9e g>nets 7^? ( purpli%-r$ t9t7 d n equal ! true ruby 9 brightness ( color & :5 held up to ! light %[ m prismatic colors ?an ! true ruby1 ow+ to ! great] disp]sion ( g>net4 ,! color also lacks v>iety 7ow+ to lack ( di*roism74 ,:ile a f9e g>net may make a fair-look+ ruby :5 by itself1 x looks inf]ior & d>k :5 beside a f9e ruby4 ,by artificial light1 too1 ! g>net is d>k z comp>$ ) ! true ruby1 & ! latt] %[s its color at a di/ance mu* m /rongly ?an ! g>net4 ,! r$ zircon1 or true hyac9?1 is r>e4 7,_m hessonite g>nets are sold z hyac9?s 9 ! trade4 ,^! are usually ( a br[ni% r$47 ,! r$ ( ! hyac9? is nev] equal to t ( ! ruby4 ,x is usually m somb]1 & a bit incl9$ to a br[ni% ca/4 ,! disp]sion ( zircon1 too1 is s l>ge 7ab\t #hg p] c5t4 ( t ( diamond7 t "s little color-play is likely to appe> along ) ! intr9sic color4 ,! lu/] too is almo/ adamant9e :ile t ( ruby is s(t] & vitre\s4 ,al?\gh /rongly d\bly refract+1 ! hyac9? %[s sc>cely any di*roism & ?us lacks v>iety ( color4 ,h5ce a tra9$ eye w at once note ^! diff]5ces & n conf\nd ! /one ) ruby4 ,sp9els1 :5 r$1 are almo/ always m yell[i% or m purpli% ?an f9e corundum rubies4 ,!y are also s+ly refract+ & h5ce exhibit no di*roism & !re=e lack v>iety ( color z comp>$ ) true ruby4 ,"s especially f9e ones1 h[ev]1 are ( a good en\gh r$ to deceive ev5 jewel]s ( exp]i5ce1 & "o 9 p>ticul> t ,i h 9 m9d has be5 ! r\nds ( ! /ores & has nev] be5 pron\nc$ a sp9el1 al?\gh sev]al exp]ts h insi/$ t x 0 a sci5tific ruby4 ,! use ( a di*roscope w\ld h sav$ !m t error1 = ! /one is s+ly refract+4 ,sp9els are usually cle>] & m transp>5t ?an g>nets & %[ _! color bett] at a di/ance or :5 9 a poor light4 ,t\rmal9e ( ! r$di% v>iety 7rubellite7 is seldom ( a deep r$4 ,x is m incl9$ to be p9ki%4 ,! di*roism ( t\rmal9e is /rong] ?an t ( ruby & m obvi\s to ! unaid$ eye4 ,! r$ ( ! rubellite %\ld n deceive anyone :o has ev] se5 a f9e corundum ruby4 ,,yell[ ,,/ones ,consid]+ next ! /ones ( yell[ color1 we h ! foll[+ species to deal )3 7#a7 diamond1 7#b7 corundum1 7#c7 preci\s topaz1 7#d7 qu>tz1 7#e7 b]yl1 7#f7 zircon1 7#g7 t\rmal9e4 ,,yell[ ,,zircon ,,resembles ,,yell[ ,,diamond4 ,"h we h less opportunity to judge ( ! species by ! color ?an 0 ! case ) ! r$ /ones4 ,! diamond1 ( c\rse1 is easy to tell1 n by ! k9d ( yell[ t x displays1 = x v>ies greatly 9 t respect1 b r by its prismatic play bl5d$ ) ! intr9sic color4 ,its lu/] also gives an imm$iate clue to its id5tity4 ,x is necess>y1 h[ev]1 to be sure t we are n be+ deceiv$ by a yell[ zircon1 = ! latt] has consid]able fire & a ke5 lu/]4 ,its /rong d\ble refraction & its relative s(tness1 z well z its great d5sity w s]ve to di/+ui% x4 ,( ! o!r yell[ /ones1 ! true or preci\s topaz is frequ5tly incl9$ to a p9ki% or w9e yell[ & _m su* /ones lose all _! yell[ 7reta9+ _! p9k7 :5 g5tly heat$4 ,! s-call$ p9k$ topazes are ?us produc$4 ,! yell[ corundum r>ely has a color t is at all di/9ctive4 ,z f> z color goes ! mat]ial might be yell[ qu>tz1 or yell[ b]yl1 or yell[ zircon1 or yell[ t\rmal9e 7,ceylon type74 ,_m ( ! yell[i% t\rmal9es h a decid$ly gre5i% ca/ 7gre5i%-yell[ *rysob]yl might resemble ^! also74 ,h[ev]1 9 g5]al if "o has a yell[ /one to det]m9e x w be saf] to make specific gravity or h>dness te/s1 or bo?1 be=e decid+1 r ?an to rely ^u color4 ,,lesson ,,xii ,,color--,cont9u$ ,,gre5 ,,/ones ,let u fir/ consid] :at m9]al species are mo/ likely to give u gre5 /ones4 ,omitt+ ! semi-preci\s opaque or transluc5t /ones we h3 #a4 ,grass-gre5 b]yl 7! em]ald7 :i* is1 ( c\rse1 fir/ 9 value among ! gre5 /ones & fir/ 9 ! f9e quality ( its color4 #b4 ,t\rmal9e 7"s specim5s ( :i* p]haps m ne>ly approa* ! em]ald ?an any o!r gre5 /ones74 #c4 ,! demantoid g>net 7sometimes call$ oliv9e 9 ! trade74 #d4 ,true oliv9e 7! p]idot & ! *rysolite ( ! trade74 #e4 ,blui%-gre5 b]yl 7aquam>9e74 #f4 ,gre5 sapphire 7,ori5tal em]ald or ,ori5tal aquam>9e74 #g4 ,*rysob]yl 7alex&rite & also ! gre5i%-yell[ *rysob]yl74 #a4 ,consid]+ fir/ ! em]ald1 we h z legitimate a use ( color 9 di/+ui%+ a /one z c\ld be select$1 = em]ald ( f9e grass-gre5 color is n equal$ by any o!r preci\s /one 9 ! ri* velvety "* ( its color4 ,we h to bew>e "h1 h[ev]1 ( ! f9e glass imitations1 :i*1 :ile lack+ ! v>iety ( true em]ald1 because ( lack ( di*roism1 are nev]!less ( a color s ne>ly l t ( ! em]ald t no "o %\ld attempt to decide by color alone z to :e!r a /one is g5u9e or imitation em]ald4 ,if a h>dness te/ %[s t ! mat]ial is a g5u9e h>d /one & n a pa/e1 !n "o :o is well accu/om$ to ! color ( f9e em]ald c say at once :e!r a /one is a f9e em]ald or "s o!r h>d gre5 /one4 ,:]e ! color is less f9e1 h[ev]1 "o might well refuse to decide by ! color1 ev5 :5 sure t ! mat]ial is n glass1 = "s f9e t\rmal9es approa* "s ( ! poor] em]alds 9 ri*ness ( color4 ,,! ,,sci5tific ,,em]ald ,,fraud4 ,no sci5tific em]alds ( m>ketable size h ev] be5 produc$ z f> z c be le>n$4 ,_m attempts to reproduce em]ald by melt+ b]yl or em]ald ( inf]ior color h result$ only 9 ! production ( a b]yl glass1 :i*1 :ile its color might be ( desirable %ade1 0 s(t] & light] 9 weight ?an true em]ald4 ,x 0 also a true glass & h5ce s+ly refract+ & )\t di*roism1 :]eas em]ald is cry/all9e 7n glassy or amorph\s71 is d\bly refract+1 & %[s di*roism4 ,d n be misl$1 !n1 into buy+ or sell+ an imitation ( em]ald "u ! t]ms syn!tic1 sci5tific1 or recon/ruct$1 z su* t]ms1 :5 s us$1 are us$ to deceive "o into ?9k+ t ! product (f]$ be>s ! same relation to ! true em]ald t sci5tific rubies & sapphires be> to ! natural /ones4 ,su* is n ! case4 ,ab\t ! mo/ dang]\s imitation ( ! em]ald t is ev] se5 9 ! trade is ! triplet t has a top & a back made ( true b pale b]yl 7! same m9]al z em]ald1 b n ( ! "r color7 & a ?9 slice ( deep em]ald gre5 glass laid betwe54 ,?is slice ( glass is usually plac$ beh9d ! girdle s t a file w n f9d any po9t ( attack4 ,! specific gravity ( ! triplet is practically t ( em]ald1 its color is (t5 v good1 & x is d\bly refract+4 ,x is ?us a dang]\s imitation4 7,see ,fig4 #h47 ,,em]ald ,,triplets4 ,a c>eful exam9ation ( "o ( ^! triplets1 9 ! unset condition1 ) a good l5s1 w reveal ! ?9 l9e ( junction ( ! b]yl ) ! glass4 7,! surface lu/]s ( ! two mat]ials are en\gh diff]5t = ! tra9$ eye to detect ! m>g9 at once47 ,su* a triplet1 if held 9 ! sun1 w reflect onto a c>d two images 9 pale or :ite light1 "o com+ f ! top surface ( ! table & ! o!r f ! top surface ( ! glass slice )94 ,9 o!r words1 x acts 9 ?is respect l a d\blet4 ,a true em]ald w\ld give only "o su* reflection1 :i* w\ld come f ! top surface ( ! table4 ,illu/ration3 ,,fig4 #h4--;,,em]ald ,,triplet4 #b4 ,t\rmal9es1 :5 gre51 are usually d>k] ?an em]alds & ( a m pron\nc$ yell[ gre51 or !y may be ( too blui% a gre51 z is ! case ) "s ( ! f9e/ ( ! gre5 t\rmal9es f ,ma9e4 ,connecticut gre5 t\rmal9e t5ds m to ! d>k yell[i% gre51 & ,ceylon t\rmal9e to ! olive gre54 ,! /rong] di*roism ( ! t\rmal9e frequ5tly reveals itself to ! nak$ eye1 & !re is usually "o direction or position 9 :i* ! color ( ! /one is v inf]ior to its color 9 ! opposite direction or position4 ,mo/ t\rmal9es 7except ! v lighte/ %ades7 mu/ be cut s t ! table ( ! f9i%$ /one lies on ! side ( ! cry/al1 z1 :5 cut ) ! table ly+ across ! cry/al 7p]p5dicul> to ! pr9cipal optical axis7 ! /ones are mu* too d>k to be pretty4 ,h5ce :5 "o turns ! cut /one s t he is look+ 9 ! direction :i* 0 orig9ally up & d[n ! cry/al 7! direction ( s+le refraction & ( no di*roism7 he gets a glimpse ( a less lovely color ?an is furni%$ by ! /one 9 o!r positions4 ,) a true em]ald no su* disp>ity 9 ! color w\ld appe>4 ,!re might be a slight *ange ( %ade 7z se5 by ! nak$ eye71 b no trace ( an ugly %ade w\ld appe>4 ,by /udy+ _m t\rmal9es & a few em]alds "o may acquire an eye = ! diff]5ces ( color t *>act]ize ! two /ones1 b x is /ill necess>y to bew>e ( ! f9e glass imitation & to use ! file & also to look ) a high-p[] glass = any r\nd+ bubbles4 ,! em]ald w nev] h ! latt]4 ,! glass imitation frequ5tly does h !m4 ,! %>p jagg$ flaws & cracks t s (t5 appe> 9 em]ald are likely to appe> also 9 t\rmal9e z bo? are brittle mat]ials4 ,! glass imitations frequ5tly h su* flaws put into !m ei!r by p9*+ or by /rik+ ! mat]ial4 ,frequ5tly1 too1 wisps ( t9y air bubbles are left 9 ! glass imitations 9 su* fa%ion t unless "o scrut9izes !m c>efully ) a good l5s !y /rongly resemble ! flaws 9 natural em]ald4 ,i h ?us gone into detail z to h[ "o may di/+ui% true em]ald f t\rmal9e & f glass imitations because1 on acc\nt ( ! high value ( f9e em]ald & its infrequ5t occurr5ce1 !re is p]haps m ne$ = ! ability to discrim9ate betwe5 x & its imitations & sub/itutes ?an !re is 9 almo/ any o!r case4 ,:]e values are high ! temptation to devise & to sell imitations or sub/itutes is great & ! ne$ = skill 9 di/+ui%+ betwe5 ! real & ! false is proportionally great4 #c4 ,! demantoid g>net 7(t5 un=tunately & incorrectly call$ oliv9e 9 ! trade7 is usually ( an olive or pi/a*io %ade4 ,x may1 h[ev]1 approa* a pale em]ald4 ,! refraction be+ s+le 9 ?is1 z 9 all g>nets1 !re is little v>iety to ! color4 ,! disp]sion be+ v high1 h[ev]1 !re is a /rong t5d5cy1 9 spite ( ! dep? ( ! body color1 = ?is /one to display fire1 t is1 ra9b[ color effects4 ,! lu/]1 too1 is diamond-l z ! "n demantoid signifies4 ,) ?is acc\nt ( ! /one & a few *ances to see ! real demantoid g>net beside an em]ald no "o w\ld be likely to mi/ake "o = ! o!r4 ,! demantoid g>net is also v s(t z comp>$ ) em]ald 7#f-a_/b z aga9/ ne>ly #h74 #d4 ,true oliv9e 7! p]idot or ! *rysolite ( ! trade7 is ( a f9e leaf-gre5 or bottle-gre5 %ade 9 ! p]idot4 ,! *rysolite ( ! jewel] is usually ( a yell[] gre54 ,frequ5tly an olive-gre5 %ade is se54 ,! lu/] ( oliv9e 7:e!r ( ! p]idot %ade or n7 is oily1 & ?is may s]ve to di/+ui% x f t\rmal9e 7:i* x may resemble 9 color74 ,its d\ble refraction is v l>ge also1 s t ! d\bl+ ( ! edges ( ! re> facets may easily be se5 ?r\gh ! table ) a l5s4 ,! di*roism is feeble too1 :]eas t ( t\rmal9e is /rong4 ,no "o w\ld be likely to confuse ! /one ) true em]ald aft] /udy+ :at has prec$$4 #e4 ,blui%-gre5 b]yl 7aquam>9e7 is usually ( a pale transp>5t gre5 or blue gre5 7almo/ a pure pale blue is also f\nd74 ,hav+ all ! prop]ties ( its m valuable v>iety1 em]ald1 ! pale b]yl may1 by ! use ( ^! prop]ties1 be di/+ui%$ f ! pale blue-gre5 topaz :i* s /rongly resembles x 9 color4 #f4 ,gre5 sapphire seldom ev5 approa*es em]ald 9 f95ess ( color4 ,:5 x remotely sugge/s em]ald x is call$ ,ori5tal em]ald to d5ote t x is a corundum gem4 ,mo/ gre5 sapphires are ( too blue a gre5 to resemble em]ald4 ,"s are really ,ori5tal aquam>9es4 ,9 "s cases ! gre5 ( ! gre5 sapphire is due to ! pres5ce1 )9 ! cut /one1 ( bo? blue & yell[ portions1 ! light f :i*1 be+ bl5d$ by its reflection )9 ! /one1 em]ges z gre5 z se5 by ! unaid$ eye1 :i* _c analyze colors4 ,! d>k sapphires ( ,au/ralia are frequ5tly gre5 :5 cut 9 "o direction & deep blue :5 cut 9 ! opposite direction4 ,! gre51 h[ev]1 is seldom pleas+4 #g4 ,*rysob]yl z usually se5 is ( a yell[i% gre54 ,! f9e gem *rysob]yls kn[n z alex&rites1 h[ev]1 h a pleas+ blui% gre5 or deep olive gre5 color by daylight & *ange 9 a mo/ surpris+ fa%ion by artificial light "u :i* !y %[ raspb]ry r$ t9ts4 ,?is *ange1 accord+ to ,g4 ,f4 ,h]b]t-,smi?1 is due pr9cipally to ! fact t ! balance 9 ! spectrum ( light transmitt$ by ! /one is s delicate t :5 a light1 ri* 9 %ort wave l5g?s1 falls ^u x ! blue gre5 effect is evid5t1 :]eas :5 ! light is ri* 9 long wave l5g?s 7r$ end ( ! spectrum71 ! :ole /one appe>s r$4 ,! /rong di*roism ( ! species also aids ?is contra/4 ,! *rysob]yls ( ! cat's-eye type 7( fibr\s or tubul> int]nal /ructure7 are usually ( olive gre5 or br[ni%-gre5 %ades4 ,^? :o wi% to fur!r /udy color di/9ctions 9 gre5 /ones are recomm5d$ to see ! *apt]s on b]yl 7pp4 #ahd-aif71 p]idot 7pp4 #bbe-bbg71 corundum 7pp4 #agb-ahc71 t\rmal9e 7pp4 #bai-bbd71 *rysob]yl 7pp4 #bcc-bcg71 & g>net 7demantoid1 pp4 #baf-bah7 9 ,g4 ,f4 ,h]b]t-,smi?'s ,gem-,/ones4 ,,lesson ,,xiii ,,color--,cont9u$ ,,blue ,,/ones ,! species t furni% blue /ones 9 suffici5t numb] to des]ve consid]ation are1 aside f opaque /ones3 #a4 ,corundum 7sapphire74 #b4 ,sp9el4 #c4 ,t\rmal9e4 #d4 ,topaz4 #e4 ,diamond4 #f4 ,zircon4 #a4 ,( ^! m9]als ! only species t furni%es a f9e1 deep velvety blue /one is ! corundum1 & f9e specim5s ( ! cornfl[] blue v>iety are v mu* 9 dem& & comm& high prices4 ,! color 9 sapphires ranges f a pale wat]y blue ?r\gh deep] %ades 7(t5 t+$ ) gre57 to ! ri* velvety cornfl[] blue t is s mu* 9 dem&1 & on to d>k inky blues t seem almo/ black by artificial light4 ,mo/ sapphires are bett] daylight /ones ?an ev5+ /ones4 ,"s ( ! sapphires f ,montana1 h[ev]1 are ( a bright electric blue t is v /rik+ & brilliant by artificial light4 ,,h[ ,,sapphires ,,%\ld ,,be ,,cut4 ,! direction 9 :i* ! /one is cut helps det]m9e ! quality ( ! blue color1 z ! ord9>y ray 7sapphire exhibits di*roism7 is yell[i% & ugly 9 color1 & if all[$ to be conspicu\s 9 ! cut /one1 its pres5ce1 bl5d+ ) ! blue1 may give x an undesirable gre5i% ca/4 ,sapphires %\ld usually be cut s t ! table ( ! f9i%$ /one is p]p5dicul> to ! pr9cipal optical axis ( ! cry/al4 ,ano!r way ( express+ ?is fact is t ! table %\ld cross ! long axis ( ! usual hexagonal cry/al ( sapphire1 at "r angles4 ,?is s*eme ( cutt+ puts ! direction ( s+le refraction up & d[n ! f9i%$ /one1 & leaves ! ugly ord9>y rays 9 poor position to em]ge z ! light t falls ^u ! girdle edges _c ent] & cross ! /one to any ext5t4 ,to f9d out ) a f9i%$ /one :e!r or n ! lapid>y has cut x prop]ly z reg>ds its optical prop]ties "o may use ! di*roscope1 & if !re is little or no di*roism 9 evid5ce :5 look+ ?r\gh ! table ( ! /one x is prop]ly cut4 ,:]e a sapphire %[s a poor color & ! di*roscope %[s t ! table 0 laid improp]ly1 !re is "s possibility ( improv+ ! color by recutt+ to ! above indicat$ position4 ,h[ev]1 "o mu/ use mu* judgm5t 9 su* a case1 z sapphires1 l o!r corundum gems1 frequ5tly h _! color irregul>ly di/ribut$1 & ! skillful lapid>y w place ! culet ( ! /one 9 a bit ( good color1 & ?us make ! :ole /one appe> to bett] advantage4 ,x w\ld n d to alt] su* an arrangem5t1 z "o w\ld get poor] r ?an bett] color by recutt+ 9 su* a case4 ,:ile "s ( ! blue /ones ab\t to be describ$ may resemble inf]ior sapphires1 none ( !m approa*es ! bett] grades ( sapphire 9 f95ess ( blue coloration4 ,! sci5tific sapphire1 ( c\rse1 does approa* & ev5 equals ! natural sapphire s t "o mu/ "k h[ to di/+ui% betwe5 !m4 ,?is di/9ction is n "o ( color1 h[ev]1 & x w be sep>ately consid]$ a little lat]4 #b4 ,blue sp9els are infrequ5tly se5 9 comm]ce4 ,!y nev] equal ! f9e sapphire 9 _! color1 be+ m /eely4 ,!y1 ( c\rse1 lack di*roism & are s(t] ?an sapphire z well z light]4 #c4 ,blue t\rmal9es are nev] ( f9e sapphire blue4 ,! "n indicolite :i* m9]alogi/s give to ^! blue /ones sugge/s ! indigo-blue color :i* !y af=d4 ,! m>k$ di*roism ( t\rmal9e w also help detect x4 ,"s t\rmal9es f ,brazil are ( a light] %ade ( blue & are sometimes call$ ,brazilian sapphires4 #d4 ,blue topaz is usually ( a pale sky blue or gre5i% blue & is likely to be confus$ ) b]yl ( simil> color4 ,! high d5sity ( topaz 7#c4ec7 z comp>$ ) b]yl 7#b4gd7 s]ves be/ to di/+ui% x4 ,,fancy ,,blue ,,diamonds4 #e4 ,blue diamonds are usually ( v pale blui% or violet t9t4 ,a few deep] blue /ones are se5 occasionally z fancy diamonds4 ,^! are seldom z deep blue z pale sapphires4 ,ev5 ! fam\s ,hope ,blue ,diamond1 a /one ( ab\t =ty-f\r c>ats & ( great value1 is said to be too light 9 color to be consid]$ a f9e sapphire blue4 ,"s ( ! deep] blue diamonds h a /eely ca/4 ,! s-call$ blue-:ite /ones are r>ely blue 9 _! body color1 b r are s ne>ly :ite t ! blue p>ts ( ! spectra :i* !y produce are v mu* 9 evid5ce1 ?us caus+ !m to face up blue4 ,!re is little likelihood ( mi/ak+ a blui% diamond = any o!r /one on acc\nt ( ! fire & ! adamant9e lu/] ( ! diamond4 #f4 ,blue zircon1 h[ev]1 has ne>ly adamant9e lu/] & consid]able fire4 ,! color is usually sky blue4 ,su* /ones are seldom met ) 9 ! trade4 ,= a m detail$ acc\nt ( ! v>i\s blue /ones see ,g4 ,f4 ,h]b]t-,smi?'s ,gem-,/ones1 z foll[s3 ,= sapphires1 pp4 #agb-agc1 #agf1 #ahb2 = sp9el1 pp4 #bjc1 #bjd1 #bje2 = t\rmal9e1 pp4 #bbj1 #bba1 #bbc2 = topaz1 pp4 #aih1 #bjj1 #bja2 = diamond1 pp4 #acj1 #acf1 #agj1 & = zircon1 pp4 #bbi1 #bca4 ,,lesson ,,xiv ,,color--,conclud$ ,,p9k1 ,,purple1 ,,br[n1 ,,& ,,colorless ,,/ones ,,p9k ,,/ones4 ,p9k /ones are yield$ by 7#a7 corundum 7p9k sapphire71 7#b7 sp9el 7balas ruby71 7#c7 t\rmal9e 7rubellite71 7#d7 true topaz 7almo/ always artificially alt]$71 7#e7 b]yl 7morganite71 7#f7 spodum5e 7kunzite71 & 7#g7 qu>tz 7rose-qu>tz74 ,^! p9k m9]als are n easily diff]5tiat$ by color alone1 z ! dep? & quality ( ! p9k v>y greatly 9 diff]5t specim5s ( ! same m9]al & 9 ! diff]5t m9]als4 ,!re is di*roism 9 ! cases ( p9k sapphire1 p9k t\rmal9e 7/rong71 p9k topaz 7/rong71 p9k b]yl 7less pron\nc$71 & kunzite 7v m>k$ & ) a yell[i% t9t 9 "s directions t contra/s ) ! beautiful violet t9t 9 ano!r direction 9 ! cry/al74 ,p9k qu>tz is almo/ always milky1 & %[s little di*roism4 ,p9k sp9el is )\t di*roism1 be+ s+ly refract+4 ,h>dness & specific gravity te/s w be/ s]ve to di/+ui% p9k /ones f ea* o!r4 ,! color alone is n a safe guide4 ,,purple ,,/ones4 ,among ! m9]al species t furni% purple /ones1 7#a7 qu>tz is pre-em95t 9 ! f95ess ( ! purple color4 ,su* purple /ones are1 ( c\rse1 kn[n z ame?y/s4 ,aft] qu>tz come 7#b7 corundum 7,ori5tal ame?y/71 7#c7 sp9el 7alm&9e sp9el71 7#d7 g>net 7alm&9e71 & 7#e7 spodum5e 7v>iety kunzite74 ,! purple ( ! ame?y/ v>ies f ! pale/ t9ts to ! full ri* velvety grape-purple ( ! s-call$ ,sib]ian ame?y/s4 ,! latt] are ( a r$di% purple 7sometimes almo/ r$7 by artificial light1 b ( a f9e violet by daylight4 ,no o!r purple /one approa*es !m 9 f95ess ( color+1 s t "h we h a real di/9ction bas$ on color alone4 ,if ! purple is pal]1 h[ev]1 "o _c be sure ( ! m9]al by its color4 ,purple corundum 7,ori5tal ame?y/7 is seldom z f9e 9 color z ord9>y ame?y/1 & nev] z f9e z ! be/ ame?y/4 ,x is usually ( a r$d] purple1 & by artificial light is almo/ ruby-l 9 its color4 ,purple sp9els are s+ly refract+1 & lack di*roism1 & h5ce lack v>iety ( color4 ,alm&9e g>nets also %[ no di*roism & lack v>iety ( color4 ,! g>nets are1 z a rule1 apt to be m d5se 9 color ?an ! sp9els4 ,purple spodum5e 7kunzite7 is p9ki% to lilac 9 %ade--usually pale1 unless 9 l>ge masses1 & x %[s v m>k$ di*roism4 ,a yell[i% ca/ ( color may be se5 9 c]ta9 directions 9 x also1 :i* w aid 9 di/+ui%+ x f o!r purple /ones4 ,,br[n ,,/ones4 7#a7 ,diamond1 7#b7 g>net1 7#c7 t\rmal9e1 & 7#d7 zircon furni% ! pr9cipal br[n /ones4 ,diamond1 :5 br[n1 unless ( a deep & pleas+ color1 is v undesirable1 z x absorbs mu* light1 & appe>s dirty by daylight & d>k & sleepy by artificial light4 ,:5 ( a f9e gold5 br[n a diamond may h consid]able value z a fancy /one4 ,su* gold5 fancies c be di/+ui%$ f o!r br[n /ones 7except p]haps br[n zircons7 by _! adamant9e lu/]1 & _! prismatic play or fire4 ,br[n g>net 7hessonite or c9namon /one71 sometimes wrongly call$ hyac9? 9 ! trade1 is ( a deep r$di%-br[n color4 ,usually ! int]ior /ructure1 z se5 "u a l5s1 is /reaky1 hav+ a sort ( mix$ oil & wat] appe>ance4 ,br[n t\rmal9e is sometimes v pleas+ 9 color4 ,x is deep 9 %ade1 less r$ ?an c9namon /one1 & ) m>k$ di*roism1 :i* bo? br[n diamond & br[n g>net lack4 ,br[n zircon1 :ile lack+ di*roism1 is frequ5tly ri* & pleas+ 9 %ade1 & :5 well cut is v snappy1 ! lu/] be+ almo/ adamant9e1 ! disp]sion be+ l>ge1 & ! refractive index high4 ,x is useless to d5y t by ! unaid$ eye "o might be deceiv$ into ?9k+ t a f9e br[n zircon 0 a br[n diamond4 ,h[ev]1 ! l>ge d\ble refraction ( ! zircon easily di/+ui%es x f diamond 7use ! sunlight-c>d me?od or look = ! d\bl+ ( ! edges ( ! re> facets z se5 ?r\gh ! table74 ,! relative s(tness 7#g-a_/b7 also easily diff]5tiates x f diamond4 ,,colorless ,,/ones4 ,few colorless /ones o!r ?an diamond1 :ite sapphire 7*iefly sci5tific71 & qu>tz are se5 9 ! trade4 ,colorless true topaz is sometimes sold & artificially :it5$ zircon 7j>goon7 is also occasionally met )4 ,b]yl ( v light gre5 t9t or ev5 entirely colorless may also be se5 at times4 ,su* colorless /ones mu/ ( c\rse be di/+ui%$ by prop]ties o!r ?an color4 ,!y are m5tion$ "h m]ely t ! le>n] may be aw>e ( :at v>ieties ( gem m9]als occur 9 ! colorless condition1 & t all ^! m9]als also occur ) color 9 _! m usual =ms4 ,?is does n ev5 except ! diamond1 :i* is r>ely truly colorless4 ,,lesson ,,xv ,,h[ ,,to ,,tell ,,sci5tific ,,/ones ,,f ,,natural ,,gems ,x %\ld be said fir/ t ! only true sci5tific or syn!tic /ones on ! m>ket are ^? hav+ ! composition & prop]ties ( corundum1 t is to say1 ! ruby & ! sev]al color v>ieties ( sapphire1 z blue1 p9k1 yell[1 & :ite4 ,!re is also a gre5i% /one t appe>s r$di% by artificial light1 :i* is call$ sci5tific alex&rite b :i* has1 h[ev]1 ! composition & prop]ties ( ! corundum gems r ?an ^? ( true alex&rite4 ,all s-call$ sci5tific em]alds h prov$ to be ei!r ( pa/e ( "o sort or ano!r1 or else triplets hav+ a top & a back ( "s inexp5sive b h>d /one ( pale color1 & a c5tral slice ( deep gre5 glass1 ! ?ree pieces be+ cem5t$ toge!r s skillfully t ! junctions frequ5tly escape any b a v c>eful exam9ation ) a l5s4 ,,all ,,sci5tific ,,/ones ,,are ,,corundum ,,gems4 ,n[ ! fact t all true sci5tific /ones are corundum gems makes _! det]m9ation fairly simple on ! foll[+ basis3 ,among ! consid]able numb] ( corundum gems ( nature1 :e!r ruby or sapphire ( v>i\s colors1 !re is seldom f\nd "o t is entirely free f defects4 ,almo/ always1 ev5 9 :at are reg>d$ z f9e specim5s1 "o w easily f9d ) a glass1 defects 9 ! cry/allization4 ,moreov] ^! defects are *>act]i/ic ( ! corundum gems4 ,! sci5tific corundum gems1 h[ev]1 nev] h ^! specific defects4 ,h5ce ! sure/ & simple/ way ( di/+ui%+ betwe5 ! two k9ds ( /ones is to acqua9t oneself ) ! typical defects ( natural corundum gems1 & !n to look = su* defects 9 any specim5 ( ruby or sapphire t is 9 "q4 ,:ile a description ( "s ( ! mo/ common ( ! typical defects ( rubies & sapphires is to foll[1 ! jewel]1 :o may n yet be famili> ) !m by actual exp]i5ce1 owes x to himself & to 8 cu/om]s to acqua9t himself at fir/ h& ) ! natural defects ( su* mat]ial1 :i* he is always 9 a position to d ?r\gh ! c\rtesy ( repres5tatives ( h\ses deal+ 9 preci\s /ones1 if he himself does n c>ry su* mat]ial 9 /ock4 ,,typical ,,defects ,,( ,,natural ,,corundum ,,gems4 ,p]haps ! mo/ common ( ! defects ( natural corundum gems is ! peculi> appe>ance kn[n z silk4 ,?is is be/ se5 :5 a /rong light is all[$ to /ream ?r\gh ! /one at "r angles to ! obs]v]'s l9e ( sight4 ,sets ( f9e1 /raight1 p>allel l9es w be se51 & ^! w frequ5tly meet o!r sets ( simil> l9es at an angle ( #abj degrees 7l ! angle at :i* ! sides ( a regul> hexagon meet7 or ! l9es may cross ea* o!r at t angle or at an angle ( #fj degrees 7! supplem5t ( #abj degrees74 ,su* /raight p>allel l9es are nev] se5 9 sci5tific /ones1 & _! pres5ce may be tak5 to indicate positively t ! /one hav+ !m is a natural /one4 ,9 f9e specim5s ( natural ruby or sapphire su* l9es w be few & difficult to f9d1 b 9 "s position or o!r !y w usually be f\nd if ! se>* is ev5 z c>eful z t :i* "o w\ld habitually employ 9 look+ = defects 9 a diamond4 ,9 ! va/ majority ( cases no su* c>eful se>* w be requir$ to locate silk 9 natural rubies1 & if a /one t is app>5tly a ruby is free f su* defects x is almo/ a =egone conclusion x is a sci5tific /one4 ,ano!r common type ( defect 9 corundum gems is ! occurr5ce ( pat*es ( milky cl\d9ess )9 ! mat]ial4 ,a little actual acqua9tance ) ! appe>ance ( ?is sort ( defect 9 natural /ones w make x easy to di/+ui% f ! occasional cl\d9ess f\nd 9 sci5tific /ones1 :i* latt] cl\d9ess is due to ! pres5ce ( sw>ms ( m9ute gas bubbles4 ,^! t9y bubbles c be se5 "u a high p[] l5s1 & ?is sugge/s a ?ird feature t may be us$ to tell :e!r "o has a natural /one or n4 ,natural rubies & sapphires1 l sci5tific ones1 frequ5tly conta9 bubbles1 b ^! are always angul> 9 ! natural /ones1 :ile ^? ( ! sci5tific /ones are g5]ally r\nd or r\nd+1 nev] angul>4 ,to sum up ! sugge/ions already pres5t$ x may be said t1 s9ce natural & sci5tific corundum gems are compos$ ( ess5tially ! same mat]ial1 & h id5tically ! same physical & *emical prop]ties1 & frequ5tly v closely resemble ea* o!r 9 color1 x is necess>y to h rec\rse to "s o!r means ( di/+ui%+ betwe5 !m4 ,! be/ & simple/ means = ^? :o are acqua9t$ ) ! /ructural defects common to natural corundum gems is to seek = su* defects 9 any specim5 t is 9 "q1 & if no su* defects c be f\nd1 to be v sceptical z to ! naturalness ( ! specim51 inasmu* z p]fect corundum gems are v r>e 9 nature1 & :5 ( f9e color comm& exce$+ly high prices4 ,no jewel] c af=d to risk 8 reputation = k & = integrity by sell+ z a natural /one any gem :i* does n possess ! m9or defects common to practically all corundum gems4 ,,/ructural ,,defects ,,( ,,sci5tific ,,/ones4 ,s f> our te/s h be5 mo/ly negative4 ,x 0 said1 h[ev]1 t sph]ical bubbles sometimes appe> 9 sci5tific gems4 ,ano!r *>act]i/ic /ructural defect ( practically e sci5tific gem may be utiliz$ to di/+ui% !m4 ,z is well kn[n1 ! r\gh mat]ial is =m$ 9 b\les or pe>-%ap$ drops "u an inv]t$ bl[pipe4 ,! p[d]$ mat]ial is f$ 9 ) "o ( ! gases & passes ?r\gh ! flame1 melt+ z x goes1 & !n accumulat+ & cry/alliz+ bel[ z a b\le4 ,! top or head ( ?is b\le is r\nd+ f ! />t1 & h5ce ! successive lay]s ( mat]ial ga!r 9 ?9 curv$ zones4 ,! color & /ructure ( ^! successive zones are n p]fectly uni=m1 h5ce :5 cut /ones are made f ! b\les ^! curv+ p>allel lay]s may be se5 )9 by ! use ( a good l5s1 especially if ! cut /one is held 9 a /rong cross+ light1 z 0 sugge/$ :5 directions 7 giv5 above z to ! be/ way to look = silk 9 a natural /one4 ,ow+ to ! %ape ( a well cut /one x is sometimes difficult to get light ?r\gh ! mat]ial1 yet by turn+ ! /one repeat$ly1 "s position w be f\nd 9 :i* ! curv+ p>allel /ri c be se54 ,!y are easily se5 9 sci5tific ruby1 less easily 9 d>k blue sapphire1 b /ill !y c be f\nd on close se>*4 ,9 ! light color$ /ones & 9 :ite sapphire1 ! difficulty is great]1 z !re are no color v>iations 9 ! latt] case4 ,h[ev]1 ! value ( :ite sapphire is s slight1 :e!r natural or artificial1 t x is a matt] ( b little mom5t1 & :at has already be5 said z to natural defects1 applies to :ite sapphire z well z to ! color$ v>ieties1 & absolutely cle> & p]fect natural :ite sapphire is r>e4 ,"o m di/+ui%+ m>k ( ! sci5tific /ones may be add$ to give full measure to ! s*eme ( sep>ation1 t no "o ne$ be deceiv$4 ,! surface f9i% ( ! sci5tific /ones is r>ely z good z t ( ! natural mat]ial & x appe>s to be m difficult to produce a good poli% on sci5tific /ones ?an on natural ones4 ,! degree ( h>dness ( ! sci5tific /ones seems to be slightly v>iable 9 diff]5t p>ts ( ! same piece s t ! poli%+ mat]ial removes ! surface mat]ial unequally1 leav+ m9ute /reaky m>ks on ! surfaces ( ! facets4 ,possibly ?is condition might be rem$i$ by skillful treatm5t1 b h>dly at ! price obta9able = ! product1 s t a close /udy ( ! surface f9i% w sometimes help 9 di/+ui%+ betwe5 natural & artificial mat]ial4 ,any f9e specim5 ( natural ruby or sapphire w h usually receiv$ v exp]t treatm5t & a spl5did surface f9i%4 ,9 conclusion1 !n1 ! po9ts to be rememb]$ 9 det]m9+ ! orig9 ( corundum gems are f\r 9 numb]4 #a4 ,expect to f9d natural defects1 su* z silk or cl\dy pat*es1 or angul> bubbles 9 all natural /ones4 #b4 ,if bubbles are pres5t 9 artificial mat]ial !y w be r\nd or r\nd+4 #c4 ,artificial mat]ial w always h curv+ p>allel /ri )9 x4 #d4 ,! surface f9i% ( artificial mat]ial is seldom or nev] equal to t ( natural mat]ial4 ,x ought n to be necess>y to add t mat]ial f ei!r s\rce may be cut to any %ape1 & t artificial rubies may be se5 9 mo/ ,ori5tal g>b1 h5ce all specim5s %\ld h appli$ to !m ! above te/s reg>dless ( ! seem+ antiquity ( _! cut or ( _! alleg$ p$igree4 ,,lesson ,,xvi ,,h[ ,,to ,,te/ ,,an ,,unkn[n ,,gem ,hav+ n[ consid]$ sep>ately ! pr9cipal physical prop]ties by means ( :i* "o c id5tify a preci\s /one1 let u attempt to give z good an idea z ! pr9t$ page c convey ( h[ "o %\ld g ab\t det]m9+ to :at species a gem belongs4 ,,signs ,,( ,,we> ,,9 ,,an ,,em]ald4 ,to make ! matt] m concrete1 & !re=e m int]e/+1 let u consid] a real case1 ! mo/ rec5t problem1 9 fact1 t ! au?or has _h to solve4 ,a lady ( "s weal? _h pur*as$1 = a l>ge sum1 a gre5 /one :i* purport$ to be an em]ald4 ,aft] a few ye>s ( we> z a r+ /one %e notic$ "o day t ! /one _h dull$ ar\nd ! edges ( its table1 & ?9k+ t t ought n to be ! case ) a real em]ald1 %e appeal$ to a deal] 9 diamonds to "k if h] /one 0 a real em]ald4 ,! diamond m]*ant told h] frankly t1 :ile he 0 compet5t 9 all matt]s p]ta9+ to diamonds1 he c\ld n be sure ( himself reg>d+ color$ /ones1 & advis$ ! lady to see ! au?or4 ,! matt] be+ ?us introduc$1 ! lady 0 at once in=m$ t ev5 a real em]ald might %[ signs ( we> aft] a few ye>s ( ! h>d use t comes to a r+ /one4 ,:ile em]ald has1 z we saw 9 ! lesson on h>dness1 a degree ( h>dness rat$ z ne>ly #h 7#g-a_/b 9 ! table71 x is nev]!less a r brittle mat]ial & ! long s]ies ( t9y bl[s t a r+ /one is b\nd to meet ) w cause m9ute yield+ along ! expos$ edges & corn]s ( ! top facets4 ,?is be+ ann\nc$1 ! fir/ /ep 9 ! exam9ation ( ! /one 0 to clean x & to give x a c>eful exam9ation ) a t5-p[] l5s4 7,an aplanatic triplet w be f\nd be/ = ?is purpose47 ,,color4 ,! color 01 ( c\rse1 ! mo/ obvi\s prop]ty1 b1 z has already be5 said1 color is n to be reli$ ^u 9 all cases4 ,9 ?is case ! color 0 a good em]ald gre5 b a bit blu] ?an ! f9e/ grass gre54 ,a v f9e ,ma9e t\rmal9e might approa* ?is /one 9 color1 s x became necess>y to consid] ?is possibility4 ,a glass imitation1 too1 might h a color equal or sup]ior to ?is4 ,,imp]fections4 ,:ile not+ ! color1 ! imp]fections ( ! /one claim$ att5tion4 ,!y consi/$ ma9ly ( m9ute jagg$ cracks ( ! "* peculi> to brittle mat]ials su* z bo? em]ald & t\rmal9e4 ,s f> x w be not$ ei!r ( ! above m9]als might h furni%$ ! lady's gem4 ,z glass c be artificially crackl$ to produce simil> flaws ! /one might h be5 only an imitation z f> z any?+ yet le>n$ ab\t x goes4 ,,file ,,te/4 ,! next /ep 0 to te/ its h>dness by g5tly apply+ a v f9e file to an expos$ po9t at "o corn] ( ! girdle4 ,! file slipp$ on ! mat]ial z a skate slips on ice4 ,evid5tly we did n h to d ) a glass imitation4 ,,refraction4 ,kn[+ n[ t we _h a true h>d m9]al1 x rema9$ to be det]m9$ :at m9]al x 04 ,on hold+ ! /one 9 direct sunlight & reflect+ ! light onto a :ite c>d x 0 se5 at once t ! mat]ial 0 d\bly refract+1 = a s]ies ( d\ble images ( ! back facets appe>$4 ,^! d\ble images might h be5 produc$ by t\rmal9e z well z by em]ald4 7,n h[ev] by glass :i* is s+ly refract+47 ,if a direct read+ refractomet] _h be5 available ! matt] c\ld h be5 settl$ at once by read+ ! refractive indices ( ! mat]ial1 = t\rmal9e & em]ald h n only diff]5t refractive indices b h d\ble refraction to diff]5t degrees4 ,su* an in/rum5t 0 n available at ! "t & w h>dly be available to mo/ ( ^? :o are /udy+ ?is lesson1 s we c g on ) our acc\nt ( ! fur!r te/+ ( ! gre5 /one4 ,,h>dness4 ,a te/ ^u ! surface ( a qu>tz cry/al %[$ t ! /one 0 h>d] ?an qu>tz 7b s is t\rmal9e74 ,a true topaz cry/al 0 too h>d = ! r+ /one1 ^: edge slipp$ ov] ! smoo? topaz surface4 ,! gre5 /one 0 !re=e n a gre5 corundum 7,ori5tal em]ald7 z ! latt] has h>dness #i & scrat*es topaz4 ,) h>dness evid5tly betwe5 #g & #h & ) d\ble refraction & ) ! k9d ( flaws peculi> to r brittle m9]als we _h 9 all probability ei!r a t\rmal9e or an em]ald4 ,,di*roism4 ,! di*roscope 7:i* might h be5 us$ mu* e>li] 9 ! te/ b 0 n at h& at ! "t7 0 next tri$ & ! /one 0 se5 to h m>k$ di*roism--a blui% gre5 & a yell[i% gre5 appe>+ 9 ! two squ>es ( ! in/rum5t :5 ! /one 0 held 9 front ( ! op5+ & view$ aga9/ a /rong light4 ,z ei!r t\rmal9e or em]ald might ?us exhibit di*roism 7! t\rmal9e m /rongly1 h[ev]1 ?an ! em]ald7 "o m te/ 0 tri$ to f9ally decide ! matt]4 ,,specific ,,gravity4 ,! /one 0 remov$ f its sett+ & two specific gravity det]m9ations made by means ( a specific gravity bottle & a f9e *emical balance4 ,! two results1 :i* came closely alike1 av]ag$ #b4gj :i* agrees v ne>ly ) em]ald 7#b4gd7 & :i* is f> remov$ f ! specific gravity ( t\rmal9e 7#c4aj74 ,! /one 0 n[ def9itely kn[n to be an em]ald1 z ea* ( sev]al te/s agre$ ) ! prop]ties ( em]ald1 namely3 ,color--ne>ly grass gre54 ,imp]fections--l ^? ( em]ald4 ,h>dness--#g-a_/b4 ,refraction--d\ble4 ,di*roism--easily not$4 ,specific gravity--#b4gj4 ,:ile "o :o 0 accu/om$ to deal 9 f9e em]alds might n ne$ to make z detail$ an exam9ation ( ! /one z has j be5 indicat$ above1 yet = mo/ ( u :o d n h _m opportunities ( /udy+ valuable em]alds x is saf] to make sure by complete te/s4 ,"o o!r concrete example ( h[ to g ab\t te/+ unkn[n /ones mu/ suffice to conclude ?is lesson1 aft] :i* ! /ud5t1 :o has ma/]$ ! sep>ate lessons prec$+ ?is1 %\ld proce$ to te/ z _m unkn[ns z 8 "t & indu/ry p]mit 9 ord] to really make 8 own ! matt] ( ^! lessons4 ,x may be add$ "h t ! task ( te/+ a /one is mu* m rapid ?an ?is labori\s ef=t to tea* o!rs h[ to d x might indicate4 ,to "o skill$ 9 ^! matt]s only a few seconds are requir$ = ! inspection ( a /one ) ! l5s1 ! di*roscope1 or ! refractomet]1 & h>dness te/s are swiftly made4 ,a specific gravity te/ requires m "t & %\ld be resort$ to only :5 !re rema9s a reasonable d\bt aft] o!r te/s h be5 appli$4 ,n[ = our f9al example4 ,a r$ /one1 cut 9 ! =m ( a pe>-%ap$ brilliant1 0 submitt$ to ! writ] = det]m9ation4 ,x _h be5 acquir$ by an ,am]ican g5tleman 9 ,japan f an ,ea/ ,indian :o 0 9 f9ancial /raits4 ,along ) x1 z security = a loan1 ! ,am]ican obta9$ a numb] ( small] r$ /ones1 a blui% /one1 & a l>g] r$ /one4 ,! r$ /ones 7 all suppos$ to be rubies4 ,on exam9ation ( ! l>g] r$ /one ) a l5s x 0 at once not$ t ! int]nal /ructure 0 t ( sci5tific ruby4 ,,te/+ ,,o!r ,,/ones4 ,some:at da%$ by ! ann\ncem5t ( ?is discov]y ! own] began to fe> t all 8 gems 7 false4 ,exam9ation ( ! small r$ /ones %[$ abundance ( silk1 a peculi> fibr\s appe>ance )9 ! /one caus$ by its int]nal /ructure4 ,! fib]s 7 /raight & p>allel1 n curv$ & p>allel z 9 syn!tic ruby4 ,t9y bubbles ( angul> %ape also indicat$ t ! small /ones 7 natural rubies4 ,!y exhibit$ di*roism & scrat*$ topaz & x 0 !re=e decid$ t !y at lea/ 7 g5u9e4 ,! pe>-%ap$ brilliant :i* 0 fir/ m5tion$ 0 ( a peculi>1 slightly yell[i%1 r$ color4 ,x 0 v pellucid & free f any /ri ei!r ( ! /raight or curv$ types4 ,x _h 9 fact no flaws except a r l>ge nick on "o ( ! back surfaces ne> ! girdle4 ,?is 0 n 9 evid5ce f ! front ( ! /one & _h evid5tly be5 left by ! ,ori5tal gem cutt] to avoid loss 9 weight :ile cutt+ ! /one4 ,! peculi> yell[i% "* ( ! r$ color l$ u to suspect ruby sp9el4 ,! /one 0 !re=e inspect$ ) ! di*roscope & f\nd to possess no di*roism4 ,! sunlight-c>d te/1 too1 %[$ t ! /one 0 s+ly refract+4 ,a te/ ( ! h>dness %[$ t ! mat]ial b>ely scrat*$ topaz1 b 0 attack$ by sapphire4 ,x 0 !re=e judg$ to be a r$ sp9el4 ,! l>ge blui% /one :i* ! g5tleman acquir$ ) ! r$ /ones prov$ to be iolite1 sometimes call$ cordi]ite or wat]-sapphire 7,saphir d'eau71 a /one seldom se5 9 ?is c\ntry4 ,x _h m>k$ di*roism--%[+ a smoky blue color 9 "o direction & a yell[i% :ite 9 ano!r4 ,! diff]5ce 0 s m>k$ z to be easily se5 )\t ! di*roscope4 ,,lesson ,,xvii ,,suitability ,,( ,,/ones ,,= ,,v>i\s ,,types ,,( ,,jewels1 ,,z ,,det]m9$ ,,by ,,h>dness1 ,,brittl5ess1 ,,& ,,cleavability ,,h>d ,,/ones ,,n ,,necess>ily ,,t\gh4 ,z 0 sugge/$ 9 ! lesson on h>dness !re is preval5t 9 ! public m9d an errone\s belief t h>dness c>ries ) x ability to resi/ bl[s z well z abrasion4 ,n[ t x does n foll[ t because a preci\s /one is v h>d1 x w we> well1 %\ld be made pla94 ,"s r h>d m9]als are seldom or nev] us$ z gems1 9 spite ( consid]able beauty & h>dness1 because ( _! great brittl5ess4 ,o!r /ones1 :ile fairly h>d & reasonably t\gh 9 c]ta9 directions1 h nev]!less s pron\nc$ a cleavage t !y d n we> well if cut1 & are sometimes v difficult to cut at all4 ,9 view ( ^! facts x w be well to consid] briefly :at /ones1 among ^? mo/ 9 use1 are suffici5tly t\gh z well z h>d1 to give good s]vice 9 jewels1 su* z r+s1 :i* are subject to r\gh we>4 ,we may also consid] ^? /ones1 ^: s(tness1 or brittl5ess1 or ready cleavability1 requires t !y %\ld be res]v$ = use only 9 ^? jewels :i*1 because ( _! nature1 receive less r\gh usage4 ,9 ord] to deal ) ! pr9cipal gems sy/ematically1 let u consid] !m 9 ! ord] ( _! h>dness1 beg9n+ ) ! h>de/ gem mat]ial kn[n1 :i* is1 ( c\rse1 diamond4 ,,durability ,,( ,,! ,,diamond4 ,=tunately ?is k+ ( gems possesses 9 addition to its great h>dness1 consid]able t\ghness1 & al?\gh x is readily cleavable 9 c]ta9 directions x nev]!less requires a notable am\nt ( =ce appli$ 9 a p>ticul> direction to cause x to cleave4 ,al?\gh %>p knocks w occasionally flake (f ?9 lay]s f diamonds :5 r\ghly worn 9 r+s1 or ev5 9 extreme cases fracture !m1 yet ?is happ5s b seldom &1 z ! enorm\s use ( ! diamond 9 r+ m\nt+s proves1 x is entirely suitable = t purpose4 ,x foll[s t1 if a /one c /& r+ usage1 x c safely be us$ = any purpose = :i* preci\s /ones are m\nt$4 ,,! ,,corundum ,,gems4 ,next aft] ! diamond 9 h>dness come ! corundum gems1 i4 e41 ruby1 sapphire1 & ! s]ies ( corundum gems ( colors o!r ?an r$ & blue4 ,^! /ones h no noticeable cleavage & are exce$+ly t\gh1 = m9]als1 z well z v h>d4 ,we h only to consid] ! use ( impure corundum 7em]y7 z a comm]cial abrasive 9 em]y :eels1 em]y clo?1 em]y pap]1 etc41 to see t ! mat]ial is t\gh4 ,any ( ! corundum gems !re=e may be us$ 9 any type ( jewel )\t undue risk ( we> or breakage4 ,cu/om]s ( jewel]s %\ld1 h[ev]1 be caution$ aga9/ we>+ ruby or sapphire r+s on ! same f+] ) a diamond r+ 9 cases :]e x w\ld be possible = ! two /ones to rub aga9/ ea* o!r4 ,s mu* h>d] ?an ! ruby is ! diamond 79 spite ( ! seem+ clos5ess ( position 9 ,mohs's scale7 t ! slighte/ t\* ^u a ruby surface ) a diamond w produce a pron\nc$ scrat*4 ,! possessor ( diamonds & o!r /ones %\ld also be caution$ aga9/ keep+ !m loose 9 ! same jewel case or o!r conta9]1 z ! %ak+ toge!r may result 9 ! scrat*+ ( ! s(t] mat]ials4 ,! ,arabs are said to h a leg5d to ! effect t ! diamond is an angry /one & t x %\ld n be all[$ to associate ) o!r /ones le/ x scrat* !m4 ,,*rysob]yl4 ,pass+ on to ! next m9]al 9 ! scale ( h>dness we come to *rysob]yl1 :i* is rat$ z #h-a_/b on ,mohs's scale4 ,?is m9]al furni%es u ! gem1 alex&rite1 :i* is notable = its p[] to *ange 9 color f gre5 9 daylight to r$ 9 artificial light4 ,*rysob]yl also supplies ! f9e/ cat's-eyes 7:5 ! mat]ial is ( a suffici5tly fibr\s or tubul> /ructure71 & x fur!r supplies ! gre5i%-yell[ /ones frequ5tly 7?\gh incorrectly7 call$ *rysolite by jewel]s4 ,! mat]ial is v h>d & reasonably t\gh & may be us$ 9 almo/ any suitable m\nt+4 ,,sp9el4 ,aft] *rysob]yl come ! mat]ials rat$ z ab\t #h 9 h>dness4 ,fir/ & h>de/ ( ^! is sp9el1 !n comes true or preci\s topaz4 ,! v>i\s sp9els are v h>d & t\gh /ones4 ,! r\gh mat]ial p]si/s 9 turbul5t m\nta9 /reams :]e weak] m9]als are gr\nd to p[d]1 & :5 cut & poli%$1 sp9el w we> well 9 any jewel4 ,! au?or has long worn a ruby sp9el 9 a r+ on ! "r h& & has done _m ?+s t h subject$ x to h>d knocks1 yet x is /ill intact1 except = a spot t accid5tally came 9 contact ) a fa/-fly+ c>borundum :eel1 :i* ( c\rse abrad$ ! sp9el4 ,,topaz4 ,! true topaz is a bit s(t] ?an sp9el1 & ! r\gh cry/als %[ a v p]fect basal cleavage4 ,t is1 !y w cleave 9 a plane p>allel to ! bases ( ! usual or?orhombic cry/als4 ,?is be+ ! case a cut topaz is v likely to be damag$ by a bl[ or ev5 by be+ dropp$ on a h>d surface1 & x w\ld be wis] n to set su* a /one 9 a r+ unless x 0 to be b little us$1 or us$ by "o :o w\ld n engage 9 r\gh "w :ile we>+ x4 ,?us a lady might we> a topaz r+ on dress occasions = a long "t )\t damag+ x1 b x w\ld n d = a ma*9i/ to we> "o 9 a r+4 ,,gems ,,betwe5 #g ,,& #h ,,9 ,,h>dness4 ,we n[ come to a r long li/ ( gem m9]als rang+ betwe5 #g & #h 9 h>dness4 ,( ^! ! pr9cipal ones are zircon1 alm&9e g>net1 & b]yl 7em]ald & aquam>9e7 rat$ z #g-a_/b 9 h>dness1 & pyrope & hessonite g>net rat$ z #g-a_/d 9 h>dness4 ,t\rmal9e & kunzite may also be includ$ 9 ?is gr\p z be+ on ! av]age slightly above #g 9 h>dness4 ,! above m9]als are all h>d] ?an qu>tz1 & h5ce n subject to abrasion by ! qu>tz du/ :i* is ev]y:]e pres5t4 ,9 ?is respect !y are suitable = fairly h>d we>4 ,! g>nets are ( suffici5t t\ghness s t !y may be freely us$ 9 r+s--& ! ext5sive use ( ?9 slices ( g>net to top d\blets proves ! suitability ( ! mat]ial = resi/+ we>4 ,! zircon is r m brittle & ! artificially :it5$ zircons 7kn[n z j>goons7 are especially subject to breakage :5 worn 9 r+s4 ,=tunately j>goons are n commonly sold4 ,! b]yl1 :e!r em]ald or aquam>9e1 is r brittle4 ,em]alds are seldom f\nd 9 riv] gravels4 ,! mat]ial _c p]si/ 9 ! m\nta9 /reams t br+ d[n o!r & t\gh] m9]als4 ,! extreme beauty & value ( ! em]ald has l$ to its use 9 ! f9e/ jewels1 & ! temptation is /rong to set x 9 r+s1 especially 9 r+s = ladies4 ,if su* r+s are worn ) ! c>e t valuable jewels %\ld receive !y w probably la/ a long "t )\t any m s]i\s damage ?an ! dull+ ( ! %>p edges ( ! facets ar\nd ! table4 ,?is slight damage c at any "t be repair$ by a light repoli%+ ( ! affect$ facets4 ,if an em]ald is already badly %att]$1 or z x is call$ mossy 9 "*1 x w n be wise to set x 9 a r+1 z a slight %ock might complete its fracture4 ,:at has be5 said ab\t em]ald applies equally to aquam>9e except t ! value at /ake is mu* less & ! mat]ial is usually mu* fre] f cracks4 ,t\rmal9es1 l em]alds1 are brittle1 & %\ld be treat$ accord+ly4 ,"h1 h[ev]1 we are deal+ ) a mu* less exp5sive mat]ial ?an em]ald1 & if a cu/om] desires a t\rmal9e 9 a r+ m\nt+1 :ile x w be be/ to sugge/ c>e 9 we>+ x1 ! loss1 9 case ( breakage1 w usually be slight4 ,kunzite1 l all spodum5e1 has a pron\nc$ cleavage4 ,x %\ld !re=e be us$ 9 broo*es1 p5dants1 & su* jewels1 r ?an 9 r+s4 ,lapid>ies dislike to cut x "u "s conditions because ( its fragility4 ,,qu>tz ,,gems4 ,com+ d[n to h>dness #g we h ! v>i\s qu>tz gems & jade 7v>iety jadeite74 ,! pr9cipal qu>tz gems are1 ( c\rse1 ame?y/ & citr9e qu>tz 7! /one t is almo/ univ]sally call$ topaz 9 ! trade74 ,z cry/all9e qu>tz is fairly t\gh & lacks any pron\nc$ cleavage1 & z x is z h>d z any?+ x is likely to meet ) 9 use1 x is a durable /one 9 r+s or 9 o!r m\nt+s4 ,9 ! c\rse ( "t ! %>p edges w we> dull f friction ) objects c>ry+ common du/1 :i* is l>gely compos$ ( p[d]$ qu>tz itself1 & :i* !re=e gradually dulls a qu>tz gem4 ,old ame?y/s or topazes t h be5 long 9 use 9 r+s %[ ?is dull+4 ,!re is1 h[ev]1 little dang] ( fracture ) ame?y/ or topaz unless ! bl[ is sev]e & !n any /one might yield4 ,! _m semi-preci\s /ones :i* h a qu>tz basis 7su* z ! v>ieties ( waxy or cryptocry/all9e *alc$ony :i* is l>gely qu>tz 9 a v m9utely cry/all9e condition7 are (t5 ev5 t\gh] ?an ! cle> cry/alliz$ qu>tz4 ,c>nelian1 agate1 qu>tz cat's-eye1 jasp] 7conta9+ e>?y impurities71 & ^? mat]ials 9 :i* qu>tz has m or less completely replac$ o!r sub/ances1 su* z silicifi$ crocidolite1 petrifi$ wood1 *rysocolla qu>tz1 etc41 are all ne>ly z h>d & q z t\gh z qu>tz itself1 & !y make admirable /ones = inexp5sive r+s ( ! arts & crafts type4 ,,jade4 ,jade1 ( ! jadeite v>iety1 :i* is r>] ?an ! nephrite jade1 & m highly reg>d$ by ! ,*9ese1 is an exce$+ly t\gh mat]ial4 ,"o c beat a *unk ( ! r\gh mat]ial ) a hamm] )\t mak+ mu* impression ^u x4 ,x is also fairly h>d1 ab\t z h>d z qu>tz1 & ) ! two prop]ties ( t\ghness & h>dness x possesses excell5t we>+ qualities 9 any k9d ( m\nt+4 ,true jade1 :e!r jadeite or nephrite1 des]ves a l>g] use 9 inexp5sive ornam5ts1 z x may be _h ( v f9e gre5 color & x is inexp5sive & durable4 ,,s(t] ,,/ones4 ,com+ next to ^? m9]als ^: h>dness is #f or ov]1 b less ?an #g1 we h to consid] jade ( ! nephrite v>iety1 demantoid g>net 7oliv9e ( ! trade71 p]idot 7or *rysolite1 or ! oliv9e ( ! m9]alogi/71 turquoise1 moon/one1 & opal4 ,z has already be5 said ( jadeite1 ! jade ( ! nephrite v>iety1 :ile slightly less h>d1 is ab\t z t\gh a m9]al z "o c\ld expect to f9d4 ,x c take c>e ( itself 9 any situation4 ,! demantoid g>net 7! oliv9e ( ! trade7 is s beautiful & brilliant a /one t x is a pity t x is s lack+ 9 h>dness4 ,x w d v well = m\nt+ 9 su* jewels z sc>f p9s1 lavallires1 etc41 :]e b little h>d we> is met )1 b x _c be recomm5d$ = h>d r+ use4 ,! p]idot1 too1 is r s(t = r+ use & w la/ mu* bett] 9 sc>f p9s or o!r m\nt+s little subject to rubb+ or to %ocks4 ,turquoise1 al?\gh r s(t1 is fairly t\gh1 z its waxy lu/] might make "o suppose1 & 9 addition1 be+ an opaque /one1 slight dull+ or scrat*+ h>dly less5s its beauty4 ,x may !re=e be us$ 9 r+ m\nt+s4 ,h[ev]1 x %\ld be sugge/$ t mo/ turquoise is suffici5tly por\s to absorb grease1 oil1 or o!r liquids1 & its color is frequ5tly ru9$ !reby4 ,( c\rse1 su* a *ange is f> m likely to occur to a r+ /one ?an to a turquoise m\nt$ 9 "s m protect$ situation4 ,! moon/one1 be+ a v>iety ( feldsp>1 has ! pron\nc$ cleavage ( t m9]al & w n /& bl[s )\t exhibit+ ?is prop]ty4 ,moon/ones are !re=e bett] suit$ to ! less rude s]vice 9 broo* m\nt+s1 etc41 ?an to t ( r+ /ones4 ,h[ev]1 be+ comp>atively inexp5sive1 _m moon/ones1 especially ( ! *oic] blui% type1 are set 9 r+ m\nt+s4 ,! lack ( h>dness may be expect$ to dull _! surfaces 9 "t ev5 ?\gh no %ock />ts a cleavage4 ,,! ,,opal4 ,!re rema9s ! opal1 ( h>dness #f1 to be consid]$4 ,z is well kn[n opal is a solidifi$ jelly ( silice\s composition1 conta9+ also comb9$ wat]4 ,x is n only s(t b v brittle & x w crack v easily4 ,_m opals crack 9 ! pap] 9 :i* !y are sold1 p]haps because ( unequal expansion or contraction1 due to heat or cold4 ,9 spite ( ?is fragility1 ?\s&s ( f9e opals1 & a ho/ ( common] ones1 are set 9 r+s1 :]e _m ( !m subsequ5tly come to a viol5t end1 & all1 soon] or lat]1 become dull$ & require repoli%+4 ,! great beauty ( ! opal1 rival+ any m9]al 9 its color-play1 causes u to *ance ! risk ( damage 9 ord] to m\nt x :]e its vivid hues may be advantage\sly view$ by ! we>] z well z by o!rs4 ,,v ,,s(t ,,/ones4 ,( /ones s(t] ?an #f we h b few & none ( !m is really fit = h>d s]vice4 ,lapis lazuli1 #e-a_/b 9 h>dness1 has a beautiful blue color1 frequ5tly fleck$ ) :ite or ) bits ( fool's gold4 ,its surface soon becomes dull$ by h>d we>4 ,two m ( ! s(t] mat]ials1 mala*ite & azurite1 rema9 to be describ$4 ,^! are bo? v>ieties ( copp] c>bonate ) comb9$ wat]1 ! azurite hav+ less wat]4 ,bo? take a good poli%1 b fail to reta9 x 9 use1 be+ only ( h>dness #c-a_/b to #d4 ,,lesson ,,xviii ,,m9]al ,,species ,,to ,,:i* ,,! ,,v>i\s ,,gems ,,belong ,,& ,,! ,,*emical ,,composition ,,!re( ,al?\gh we h a v l>ge numb] ( diff]5t k9ds ( preci\s & semi-preci\s /ones1 to judge by ! long li/ ( names to be f\nd 9 books on gems1 yet all ^! /ones c be r simply classifi$ on ! basis ( _! *emical composition1 into "o or ano!r ( a comp>atively small numb] ( m9]al species4 ,:ile jewel]s seldom make use ( a k ( ! *emi/ry ( ! preci\s /ones 9 id5tify+ !m1 nev]!less su* a k is useful1 bo? by way ( in=mation1 & because x leads to a bett] & cle>] und]/&+ ( ! _m simil>ities among /ones ^: color might lead "o to reg>d !m z dissimil>4 ,,m9]al ,,species4 ,we mu/ fir/ consid] :at is meant by a m9]al species & f9d out :at relation exi/s betwe5 t subject & *emical composition4 ,n[ by a m9]al species is und]/ood a s+le sub/ance1 hav+ 7except = me*anically admix$ impurities7 practically a con/ant *emical composition1 & hav+ practically id5tical physical prop]ties 9 all specim5s ( x4 ,,diamond ,,& ,,corundum4 ,a *emi/ w\ld call a true m9]al a pure sub/ance1 j z sug> & salt are pure sub/ances to ! *emi/4 ,?us diamond is a m9]al species1 z is also corundum4 ,!re are _m diff]5t colors ( bo? diamond & corundum1 b ^! diff]5t colors are believ$ to be due to ! pres5ce 9 ! pure sub/ance ( impurities 9 small am\nts4 ,?us e diamond consi/s ma9ly ( pure c>bon1 & all ! corundum gems 7ruby & ! v>i\s colors ( sapphire7 consi/ ma9ly ( pure oxide ( alum9um4 ,! prop]ties ( all diamonds are practically alike & s are ! prop]ties ( all ! corundum gems :e!r r$ 7ruby71 blue 7sapphire71 yell[ 7,ori5tal topaz71 gre5 7,ori5tal em]ald71 or purple 7,ori5tal ame?y/74 ,?us all diamonds1 ( :atev] color1 belong to ! "o species1 diamond1 & 9 ?is case ! usual cu/om 9 nam+ !m agrees ) ! facts4 ,simil>ly all sapphires1 ( :atev] color1 belong to ! m9]al species corundum4 ,?us a ruby is a r$ corundum4 ,! old ,fr5* travel] & gem m]*ant1 ,tav]ni]1 tells u t 9 ! sev5te5? c5tury1 :5 he visit$ ! m9es ( ,pegu1 ! natives knew ( ! simil>ity ( ! corundum gems & ev5 call$ all by "o "n1 ) o!r names atta*$ to designate ! color4 ,s+ul>ly en\gh1 ! common "n us$ by !m 0 ruby r ?an sapphire1 z n[4 ,?us !y call$ blue corundum gems blue rubies2 yell[ corundums1 yell[ rubies1 etc4 ,x is easily se5 t if "o recognizes ! simil> nature ( all ! _m colors & %ades ( corundum t ! numb] ( ?+s t "o has to rememb] 9 ord] to be well acqua9t$ ) ^! /ones is consid]ably dim9i%$4 ,?us1 in/ead ( hav+ a :ole s]ies ( specific gravities to rememb] "o has only to rememb] t all ! corundum gems h a specific gravity ( approximately #d4 ,simil>ly !y are all ( practically ! same refractive index 7#a4gfa-a4ggj1 be+ d\bly refract+7 t !y all exhibit di*roism :5 at all deeply color$1 etc4 ,hav+ ?us indicat$ :at we mean by m9]al species & hav+ illu/rat$ ! matt] by ! cases ( diamond & corundum & fur!r hav+ /at$ t all diamonds are compos$ ( pure c>bon 7except = traces ( impurities7 & all corundum gems ma9ly ( oxide ( alum9um1 we may proce$ to consid] o!r m9]al species & f9d out :at gems !y af=d u4 ,,c>bon1 ,,! ,,only ,,elem5t ,,furni%+ ,a ,,gem4 ,x w be not$ t ! fir/ species consid]$1 diamond1 consi/$ ( b a s+le elem5t1 c>bon4 ,x is ?us exce$+ly simple 9 composition1 be+ n only a pure sub/ance b1 9 addition1 an elem5t>y sub/ance4 ,,corundum1 ! second species consid]$1 0 a little m complex1 hav+ two elem5ts1 alum9um & oxyg51 9 its make-up1 b completely & def9itely comb9$ 9 a new comp\nd t resembles nei!r alum9um nor oxyg54 ,x is ?us a comp\nd sub/ance4 ,no o!r elem5t ?an c>bon af=ds any gem-/one :5 by itself4 ,,oxides ,,( ,,metals4 ,!re is1 h[ev]1 ano!r oxide1 9 addition to alum9um oxide1 t furni%es gem mat]ial4 ,x is silicon oxide1 conta9+ ! two elem5ts silicon & oxyg54 ,silicon itself is a d>k1 gray1 cry/all9e elem5t t seems half metallic1 half non-metallic 9 its prop]ties4 ,x is nev] f\nd by itself 9 nature b ab\t tw5ty-eight p] c5t4 ( ! cru/ ( ! e>? is compos$ ( x 9 comp\nd =ms1 & "o ( ! mo/ abundant ( ^! is ,,qu>tz1 :i* is a m9]al species1 & :i* conta9s j silicon & oxyg54 ,t is1 x is oxide ( silicon4 ,n[ qu>tz is colorless :5 pure 7rock cry/al71 b x is frequ5tly f\nd color$ purple 7probably by oxide ( manganese7 & x is !n call$ ame?y/ by ! jewel]4 ,at o!r times its color is yell[ 7due to oxide ( iron7 & !n ! jewel] is prone to call x topaz1 al?\gh prop]ly speak+ t "n %\ld1 z we %all soon see1 be res]v$ = an entirely diff]5t m9]al species4 ,*alc$ony too 7:i* :5 b&$ furni%es u our agates1 & :5 r$di% our c>nelian7 is a v>iety ( qu>tz1 & prase is only qu>tz color$ gre5 by fib]s ( act9olite )9 x4 ,! common cat's-eye & ! tig]'s-eye are v>ieties ( qu>tz enclos+ fibr\s m9]als or replac+ !m :ile /ill keep+ ! arrangem5t t !y _h4 ,v5us hair /one is qu>tz conta9+ ne$le-l cry/als ( rutile1 & iris is qu>tz t has be5 crackl$ )91 s z to produce ra9b[ colors1 because ( ! effects ( ?9 lay]s ( mat]ial4 ,av5tur9e qu>tz 7sometimes call$ gold/one7 has spangles ( mica or ( "s o!r m9]al enclos$ 9 x4 ,! jasp]s are ma9ly qu>tz ) m ( e>?y impurity ?an ! prec$+ /ones4 ,?us all ?is long li/ ( /ones ( diff]+ names c be classifi$ "u ! "o m9]al species1 qu>tz4 ,toge!r !y con/itute ! qu>tz gems4 ,9 prop]ties !y are ess5tially alike1 hav+ specific gravity #b4ff1 h>dness #g1 slight d\ble refraction1 etc41 ! slight diff]5ces t exi/ be+ due only to ! pres5ce ( v>y+ am\nts ( =eign matt]4 ,,opal4 ,! opal may be consid]$ along ) ! qu>tz gems1 because1 l !m1 x is compos$ ma9ly ( oxide ( silicon1 b ! opal also has wat] comb9$ ) ! silicon oxide 7n m]ely imprison$ 9 x74 ,?us opal is a hydr\s =m ( silica 7hydr\s comes f ! ,greek ^w = wat]74 ,,sp9el4 ,all our o!r /ones are ( m complicat$ *emical composition ?an ! prec$+4 ,com+ n[ to m9]al species :i* h ?ree *emical elem5ts 9 !m we may consid] fir/ sp9el1 :i* has ! two metallic elem5ts alum9um & magnesium & ! non-metallic elem5t oxyg5 9 x4 ,x is virtually a comp\nd ( ! two oxides1 alum9um oxide & magnesium oxide4 ,! v>i\sly color$ sp9els1 l ! v>i\s corundums1 all h ! same prop]ties1 ?us !y are all ( h>dness #h or a little high]1 !y all h s+le refraction1 & all h specific gravity #c4fj4 ,,*rysob]yl4 ,ano!r m9]al species :i*1 l sp9el1 has j ?ree elem5ts 9 its composition is *rysob]yl4 ,?is m9]al conta9s ! metals alum9um & b]yllium comb9$ ) ! non-metal oxyg54 ,?us x is really to be reg>d$ z a comp\nd ( ! two oxides1 alum9um oxide & b]yllium oxide4 ,?is species furni%es u ,alex&rite1 *rysob]yl cat's-eye & less valuable *rysob]yls ( yell[i%-gre5 color4 ,all are ( ! "o species1 ! m>k$ color diff]5ce be+ due to ! pres5ce ( diff]5t impurities4 ,! cat's-eye effect 9 "o ( ! v>ieties is due to ! int]nal /ructure r ?an to ! nature ( ! mat]ial4 ,,! ,,silicates4 ,ne>ly all ( ! rema9+ preci\s /ones belong to a great gr\p ( m9]al species kn[n z ! silicates4 ,^! are s call$ because !y consi/ l>gely ( oxide ( silicon 7! mat]ial above ref]r$ to "u qu>tz gems74 ,?is oxide ( silicon is n free & sep>ate 9 ! silicates b is comb9$ *emically ) o!r oxides1 *iefly ) metallic oxides4 ,?us !re are _m diff]5t silicates because1 9 ! e>?1 _m diff]5t metallic oxides h comb9$ ) silicon oxide4 ,also 9 _m cases two or ?ree or ev5 m metallic oxides h comb9$ ) silicon oxide to make s+le new comp\nds4 ,,glass1 ,a ,,mixture ,,( ,,silicates4 ,^? :o are famili> ) glass mak+ may receive "s help at ?is po9t by rememb]+ t ! v>i\s glasses are silicates1 = !y are made by melt+ s& 7:i* is ne>ly pure oxide ( silicon7 ) v>i\s metallic oxides4 ,) lime 7calcium oxide7 & soda 7:i* yields sodium oxide7 we get soda-lime glass 7common w9d[ glass74 ,lead oxide be+ add$ to ! mixture a d5se1 v brilliant1 b s(t glass 7fl9t glass7 results4 ,cut glass di%es & pa/e gems are made ( ?is fl9t glass4 ,n[ ! glasses1 al?\gh !y are silicates1 are n cry/all9e1 b r !y are amorph\s1 t is1 )\t any def9ite /ructure4 ,nature's silicates1 on ! o!r h&1 are usually cry/alliz$ or at lea/ cry/all9e 9 /ructure4 7,9 a few cases we f9d true glasses1 volcanic glass1 or obsidian1 = example47 ,hav+ ?us introduc$ ! silicates we may n[ consid] :i* ones among ! _m m9]al silicates furni% u ) preci\s or semi-preci\s /ones4 ,,b]yl1 ,,em]ald1 ,,& ,,aquam>9e4 ,fir/ 9 value among ! silicates is b]yl1 :i*1 :5 grass gre51 we call em]ald4 ,! aquam>9e & gold5 b]yl too belong to ?is same species4 ,b]yl is a silicate ( alum9um & b]yllium4 ,t is1 x is a comp\nd 9 :i* oxide ( silicon is unit$ ) ! oxides ( alum9um & ( b]yllium4 ,!re are ?us f\r *emical elem5ts comb9$ 9 ! "o sub/ance & x is h5ce m complicat$ 9 its composition ?an any ( ! gems t we h yet consid]$4 ,x is wor?y ( note t alum9um occurs 9 ! majority ( preci\s /ones1 ! only species s f> consid]$ t lack x be+ diamond1 & ! qu>tz gems4 ,p]haps ! silicates t are next 9 importance to ! jewel]1 aft] b]yl1 are ^? :i* =m ! g>nets ( v>i\s types4 ,!re are f\r pr9cipal v>ieties ( g>net 7al?\gh specim5s ( g>net frequ5tly %[ a cross+ or bl5d+ ( ! types74 ,,g>nets4 ,! types are 7#a7 ,alm&ite g>net2 7#b7 ,pyrope g>net2 7#c7 ,hessonite g>net2 & 7#d7 ,&radite g>net4 ,^! are all silicates1 ! alm&ite g>nets be+ silicates ( iron & alum9um2 ! pyrope g>nets are silicates ( magnesium & alum9um2 ! hessonite g>nets1 silicates ( calcium & alum9um1 & ! &radite g>nets1 silicates ( calcium & iron4 ,! s-call$ alm&9e g>nets ( ! jewel] are frequ5tly ( ! alm&ite class & t5d to purpli% r$4 ,! pyrope g>nets are1 z ! "n lit]ally implies1 ( fire r$ color1 z a rule1 b !y also may be purpli% 9 color4 ,! hessonite g>nets are frequ5tly br[ni% r$ & are sometimes call$ c9namon /ones4 ,! &radite g>nets furni% ! brilliant1 ne>ly em]ald gre5 demantoids 7s (t5 call$ oliv9e by ! trade74 ,?us all ! g>nets are silicates & yet we h ^! f\r pr9cipal m9]al species1 :i*1 h[ev]1 are m closely relat$ to ea* o!r 9 cry/al =m1 9 "* ( composition & 9 g5]al prop]ties1 ?an is usual among ! o!r silicates4 ,specim5s :i* h any "o ( ! f\r types ( composition unbl5d$ ) any ( ! o!r types w\ld be f\nd to be exactly alike 9 prop]ties4 ,z 0 sugge/$ above1 h[ev]1 !re is a great t5d5cy to bl5d & ?is is well illu/rat$ by ! magnific5t rhodolite g>nets1 ( rhodod5dron hue :i* 7 f\nd 9 ,macon ,c\nty1 ,nor? ,c>ol9a4 ,^! _h a composition betwe5 alm&ite & pyrope1 t is1 !y _h bo? magnesium & iron ) alum9um & silica4 ,! true ,,topaz next calls = consid]ation z x too is a silicate4 ,! metallic "p consi/s ( alum9um1 & !re are pres5t also ! non-metals fluor9e & hydrog54 ,"h we h five elem5ts 9 ! "o sub/ance4 ,v>i\s specim5s ( ?is species may be w9e yell[1 light blue1 or blui% gre51 p9k or colorless1 yet !y all h ess5tially ! same prop]ties4 ,,t\rmal9e is ab\t z complicat$ a m9]al z we h4 ,x is a v complex silicate1 conta9+ alum9um1 magnesium1 sodium 7or o!r alkali metal1 z1 = example1 li?ium71 iron1 boron1 & hydrog54 ,z ,rusk9 says ( x 9 8 ,! ,e?ics ( ! ,du/1 :5 ,m>y asks & :at is x made (8 ,a little ( ev]y?+2 !re's always fl9t 7silica7 & clay 7alum9a7 & magnesia 9 x & ! black is iron1 accord+ to its fancy2 & !re's boracic acid1 if y "k :at t is3 & if y don't1 ,i _c tell y to-day & x doesn't signify2 & !re's pota% & soda2 & on ! :ole1 ! *emi/ry ( x is m l a m$ival doctor's prescription1 ?an ! mak+ ( a respectable m9]al4 ,! v>i\s t\rmal9es v closely resemble ea* o!r 9 _! prop]ties1 ! slight diff]5ces correspond+ to diff]5ces 9 composition d n alt] ! g5]al nature ( ! mat]ial4 ,,moon/one belongs to a species ( m9]al kn[n z feldsp>4 ,! p>ticul> feldsp> t furni%es mo/ ( ! moon/one is or?oclase1 a silicate ( potassium & alum9um4 ,ano!r feldsp> sometimes se5 z a semi-preci\s /one is ,labradorite4 ,amazonite1 also1 is a feldsp>4 ,sun/one is a feldsp> :i* includes t9y flakes or spangles ( "s o!r m9]al4 ,! m9]al species oliv9e gives u p]idot4 ,x is a silicate ( magnesium4 ,,zircon is itself a species ( m9]al & is a silicate ( zirconium4 ,! names hyac9?1 jac9?1 & j>goon are appli$ to r$1 yell[1 & colorless zircon 9 ! ord] z giv54 ,,jade may be ( any ( sev]al diff]5t species ( m9]als1 all ( :i* are v t\gh4 ,! pr9cipal jades belong1 h[ev]1 to "o or ! o!r ( two species1 jadeite & nephrite4 ,jadeite is a sodium alum9um silicate & nephrite1 a calcium magnesium silicate4 ,leav+ ! silicates we f9d v few gem m9]als rema9+4 ,! phosphates furni% u turquoise1 a hydr\s alum9um phosphate1 ) copp] & iron4 ,v>iscite is also a phosphate 7a hydrat$ alum9um phosphate74 ,! c>bonates give u mala*ite & azurite1 bo? c>bonates ( copp] ) comb9$ wat]1 ! mala*ite hav+ m wat]4 ,,lesson ,,xix ,,! ,,nam+ ,,( ,,preci\s ,,/ones ,ow+ to ! confusion :i* may result f a lack ( uni=mity 9 ! nam+ ( preci\s /ones1 x is v desirable t jewel]s & /one m]*ants in=m !mselves 9 reg>d to ! correct use ( ! names ( ! gems1 & t !y use c>e 9 speak+ & 9 writ+ su* names4 ,z ne>ly all preci\s & semi-preci\s /ones are d]iv$ f a relatively small numb] ( m9]al species1 z we saw 9 ,lesson ,,xviii41 & z ! sci5ce ( m9]alogy has a v ord]ly & sy/ematic me?od ( nam+ ! m9]als1 ! be/ results are _h 9 ! nam+ ( gems :5 we use1 z f> z is possible1 ! language ( m9]alogy4 ,,anci5t ,,usage4 ,long e/abli%$ cu/om & usage1 h[ev]1 mu/ be obs]v$1 = any sy/em ( nam+ mu/ be g5]ally und]/ood 9 ord] to be useful4 ,?us ! prop] "n = blood r$1 cry/alliz$ oxide ( alum9um1 ( gem quality1 accord+ to ! m9]alogical sy/em ( nam+1 w\ld be r$ corundum1 b t same mat]ial is ref]r$ to 9 ! ,old ,te/am5t ?us 79 speak+ ( wisdom71 ,%e is m preci\s ?an rubies4 ,x is obvi\sly necess>y to keep & to use all su* t]ms z h be5 = ye>s e/abli%$ 9 usage1 ev5 ?\gh !y d n agree ) ! sci5tific me?od ( nam+ ! p>ticul> m9]al4 ,x is1 h[ev]1 necess>y t any "n1 ?us reta9$1 %\ld be correctly us$1 & t x %\ld n be appli$ to m ?an "o mat]ial4 ,?us ! t]m ruby %\ld be res]v$ exclusively = r$ corundum1 & n appli$ to o!r r$ m9]als su* z g>net1 sp9el1 etc41 z is too (t5 done4 ,x w be ! purpose ( ?is lesson to attempt to set =? z cle>ly & z briefly z possible :at con/itutes good usage 9 ! nam+ ( ! pr9cipal /ones1 & also to po9t out :at incorrect usage is mo/ 9 ne$ ( be+ avoid$4 ,to cov] ! subject sy/ematically we w adopt ! ord] ( h>dness t we did 9 discuss+ m9]al species 9 ,lesson ,,xviii4 ,,fancy ,,diamonds4 ,beg9n+ ) ! h>de/ ( all gems1 ! diamond1 we h no difficulty z reg>ds nam+1 z all specim5s ( ?is m9]al1 reg>dless ( color1 are call$ diamonds4 ,:5 x is necess>y to designate p>ticul> colors or t9ts1 or diff]5ces 9 t9t1 additional names are us$--= example1 all diamonds ( pron\nc$ & pleas+ color are call$ fancy diamonds 9 ! trade4 ,c]ta9 ( ^! fancy diamonds are /ill fur!r def9$ by us+ a "n specify+ ! color1 z1 = example1 can>y diamonds 7:5 ( a f9e bright yell[71 or gold5 fancies1 :5 ( a f9e gold5 br[n1 or orange1 or p9k1 or abs9! gre51 or violet1 z ! case may be4 ,,names ,,( ,,v>i\s ,,grades ,,( ,,:ite ,,diamonds4 ,! great majority ( ! diamonds :i* come on ! m>ket z cut /ones belong1 h[ev]1 to ! gr\p :i* w\ld be spok5 ( z :ite diamonds1 b _m qualify+ names are ne$$ to express ! degree ( approa* to pure :ite possess$ by diff]5t grades ( ^! diamonds4 ,?us ! t]ms3 #a1 ,jg]s2 #b1 ,riv]s2 #c1 ,blue ,wesseltons2 #d1 ,wesseltons2 #e1 ,top ,cry/als2 #f1 ,cry/als2 #g1 v light br[n2 #h1 ,top ,silv] ,capes2 #i1 ,silv] ,capes2 #aj1 ,capes2 #aa1 ,yell[s1 & #ab1 ,br[ns1 describe increas+ dep? ( color1 & h5ce decreas+ value 9 diamonds4 ,,popul> ,,names4 ,c]ta9 m popul> names = diamonds ( diff]+ degrees ( :it5ess may next be set =?4 ,! t]m blue :ite 7a mu* abus$ expression1 by ! way7 %\ld be appli$ only to diamonds ( su* a close approa* to pure :it5ess ( body sub/ance1 z se5 on edge 9 ! pap] t1 :5 fac$ up & undimm$1 !y give su* a /rong play ( prismatic blue t any slight trace ( yell[ 9 _! sub/ance is completely disguis$1 & ! effect ^u ! eye is notably blue4 ,?is w\ld be ! case ) /ones ( ! grades f #a ?r\gh #d 9 ! li/ above4 ,grades #e & #f might prop]ly be call$ f9e :ite1 & grades #g1 #h1 & #i simply :ite4 ,grade #aj is frequ5tly spok5 ( z comm]cial :ite1 & grade #aa sometimes z (f color4 ,grade #ab includes all degrees ( br[nness except ! v light %ades & ! deep1 pretty %ades ( ! fancy br[ns4 ,,rubies4 ,leav+ ! nam+ ( ! diff]5t colors ( diamonds we come to ! gems furni%$ u by ! m9]al kn[n z corundum4 ,z we h previ\sly se51 ?is m9]al occurs 9 _m diff]5t colors & ) wide diff]5ces ( t9t & %ade 9 ea* ( ! pr9cipal colors4 ,! be/ practice ) reg>d to nam+ ! corundum gems is to call ! r$ mat]ial1 :5 ( a good1 full r$ ( pleas+ %ade1 ruby4 ,! f9e/ %ades ( blood r$ are usually call$ ,burmah rubies because m rubies ( ?is quality are f\nd 9 ,burmah ?an any:]e else4 ,any ruby ( ! requir$ %ade w\ld1 h[ev]1 be call$ a ,burmah ruby 9 ! trade reg>dless ( its geographical orig94 ,! mo/ desirable t9t among ,burmah rubies is t :i* is kn[n z pigeon blood 9 color4 ,?is color is p]haps m accurately def9$ z l ! color 9 ! c5t] ( ! r$ ( ! sol> spectrum4 ,c]ta9 slightly deep] r$ rubies are said to be ( beef blood color4 ,! ,engli% are said to pref] ^!4 ,^? ( slightly light] t9t ?an pigeon blood are sometimes ref]r$ to z ( ,fr5* color1 f ! fact t !y are pref]r$ by ,fr5* connoisseurs4 ,rubies ( d>k1 g>net-l %ade are kn[n z ,siam rubies1 _m su* be+ f\nd 9 t c\ntry4 ,light p9ki% rubies are call$ ,ceylon rubies4 ,x %\ld be cle>ly kept 9 m9d t all ^! rubies are ( r$ corundum1 & t 9 all _! di/9ctive prop]ties except color !y are ess5tially simil>4 ,,sapphires4 ,corundum ( f9e blue color is kn[n z sapphire4 ,! cornfl[] blue seems to be mo/ 9 favor at pres5t4 ,su* sapphires are sometimes call$ ,ka%mir sapphires because _m f9e ones come f t ,/ate4 ,ceylon sapphires are usually pal] ?an ! cornfl[] blue4 ,montana sapphires are usually ( gre5i% blue or pale electric blue4 ,su* f9e blue /ones z are m9$ 9 ,montana w\ld be sold "u ano!r "n accord+ to ! quality ( _! color1 & n z ,montana sapphires4 ,au/ralian sapphires are ( a v deep1 inky blue1 & d n comm& a high price4 ,"h aga91 z ) rubies1 ! classification dep5ds ^u ! color r ?an ^u ! orig91 al?\gh ! geographical names t are us$1 correctly /ate ! usual s\rce ( /ones ( ! p>ticul> color4 ,all corundums o!r ?an ruby & blue sapphire are usually call$ by ! t]m sapphire1 ) a qualify+ adjective designat+ ! color2 ?us we may h p9k sapphire1 gold5 sapphire1 gre5 sapphire1 etc4 ,:5 ( v f9e yell[ color ! yell[ sapphire is sometimes call$ ,ori5tal topaz by jewel]s1 ! t]m ,ori5tal z ?us us$ indicat+ t ! mat]ial is corundum4 ,we also h ,ori5tal ame?y/ & ,ori5tal em]ald = ! purple1 & ! f9e gre51 & ,ori5tal aquam>9e = ! light blue-gre5 corundum4 ,! yell[ corundum is also sometimes call$ ,k+ topaz1 especially 9 ,ceylon4 ,inf]ior sapphires ( almo/ e conceivable color are frequ5tly assort$ 9 lots & sold z fancy sapphires4 ,su* lots1 h[ev]1 almo/ always ne$ reclassification z !y (t5 conta9 z _m z a doz5 m9]al species besides corundum4 ,sapphires & rubies ( m9ute tubul> int]nal /ructure frequ5tly display a beautiful six-po9t$ /> :5 cut to a r\nd-topp$ cabo*on %ape & expos$ to direct sunlight or to light f any o!r s+le s\rce4 ,su* /ones are nam$ /> sapphire & /> ruby4 ,! artificial rubies & sapphires %\ld all be call$ sci5tific ruby or sapphire1 & n recon/ruct$ or syn!tic z none are made to-day f small1 real rubies1 & z ! process is 9 no s5se a *emical syn!sis4 ,,*rysob]yl4 ,leav+ ! corundum gems we come next to *rysob]yl4 ,:5 ! gems furni%$ by ?is m9]al are ( a f9e gre5 by daylight1 & ( a raspb]ry r$ by artificial light1 z is sometimes ! case1 !y %\ld be call$ ,alex&rites 7aft] ! ,cz> ,alex&] ,,ii41 9 ^: dom9ions1 & on ^: bir?day1 ! fir/ specim5s are said to h be5 discov]$74 ,:5 *rysob]yl is ( fibr\s or tubul> int]nal /ructure x af=ds cat's-eyes 7:5 cabo*on cut71 & ^! %\ld be specifically nam$ z *rysob]yl cat's-eye to di/+ui% !m f ! less beautiful & less valuable qu>tz cat's-eyes4 ,o!r v>ieties ( *rysob]yl 7mo/ ( ^? m>ket$ are ( a gre5i%-yell[ color7 are correctly nam$ simply *rysob]yls4 ,su* /ones are1 h[ev]1 sometimes incorrectly call$ *rysolite by ! trade1 & ?is practice %\ld be correct$1 z ! t]m *rysolite applies correctly only to ! m9]al oliv9e :i* gives u ! p]idot4 ,,sp9el4 ,next 9 ! ord] t we h *os5 comes sp9el4 ,! m valuable sp9els are ( a r$ color t some:at closely approa*es ! r$ ( "s rubies4 ,su* r$ sp9els %\ld be call$ ,ruby sp9el 7& n sp9el ruby74 ,! /ones !mselves sometimes get mix$ ) corundum rubies 7!y are frequ5tly f\nd 9 ! same gem gravels71 & ?is makes x all ! m necess>y t bo? /ones & names %\ld be cle>ly di/+ui%$4 ,"s deal]s call r$di% sp9els ,balas ruby 7rose r$71 & orange r$ ones rubicelle4 ,violet r$ sp9el is sometimes call$ alm&9e sp9el4 ,x is v desirable t ! "n ( ! m9]al species1 sp9el1 %\ld be us$1 toge!r ) a qualify+ color adjective1 9 nam+ gems ( ?is species1 r ?an su* t]ms z rubicelle1 balas ruby1 sp9el ruby1 etc4 ,,topaz4 ,we come n[ to topaz4 ,true1 or preci\s topaz1 z x is usually call$1 to di/+ui% x f ! s(t] & less valuable yell[ qu>tz1 is seldom se5 9 ! trade to-day4 ,jewel]s almo/ always mean yell[ qu>tz :5 !y speak ( topaz4 ,?is is an un=tunate confusion ( t]ms1 & "o :i* w be h>d to eradicate4 ,!re is seldom any inju/ice done ?r\gh ?is misnam+1 z ! price *>g$ is usually a fair "o = ! mat]ial (f]$4 ,consid]ably high] prices w\ld be necess>y if true topaz 0 9 "q4 ,an in/ance f ! writ]'s exp]i5ce w s]ve to illu/rate ! confusion t exi/s 9 ! trade z to :at %\ld be call$ topaz4 ,a jewel] ( m ?an ord9>y acqua9tance ) gems exhibit$ "s f9e broo* /ones z specim5s ( topaz4 ,on rem>k+ t !y 7 ( c\rse citr9e qu>tz r ?an true topaz1 ! au?or 0 met ) ! /atem5t t ! broo* /ones 7 real topaz4 ,9 ord] to make cle> to ! deal] ! diff]5ce betwe5 ! two species1 ! au?or ask$ him if he hadn't "s small] topazes 9 /ock t _h co/ him consid]ably m ?an ! broo* /ones4 ,! deal] repli$ t he _h "s small w9e yell[ topazes = :i* he _h paid m1 & he produc$ !m4 ,! latt] /ones 7 true ,brazilian topazes4 ,mo/ ( !m _h t9y1 crackly flaws 9 !m1 z is frequ5tly ! case1 &1 z ! writ] po9t$ out to ! deal]1 !y _h be5 b\ght by ! c>at1 :]eas ! l>ge broo* /ones _h be5 b\ght at a c]ta9 price p] p5nyweight4 ,9 fact ! little /ones _h co/ m p] c>at ?an ! l>g] ones _h p] p5nyweight4 ,! deal] 0 !n ask$ if !re mu/ n be "s diff]5ce 9 ! real nature ( ! two lots to ju/ify pay+ m p] c>at = small1 imp]fect /ones ?an p] p5nyweight = l>ge p]fect ones4 ,he ( c\rse ackn[l$g$ t x w\ld appe> reasonable t su* 0 ! case4 ,he 0 next %[n t 8 small true topazes scrat*$ 8 l>ge /ones easily1 b ! l>ge ones c\ld get no hold ^u ! surfaces ( ! small ones4 7,x w be rememb]$ t topaz has a h>dness ( #h1 :ile qu>tz has a h>dness ( #g47 ,! explanation !n foll[$ t ! two lots 7 f two entirely di/9ct m9]als1 topaz & qu>tz1 & t ! =m] 0 h>d]1 took a some:at bett] poli%1 & 0 m r>e 79 f9e colors7 ?an qu>tz4 ,( c\rse ! yell[ qu>tz %\ld be sold "u ! prop] "n1 citr9e qu>tz4 7,f ! same root t we h 9 citrus z appli$ to fruits4 ,= example ! ,cali=nia ,citrus ,fruit ,gr[]s' ,association1 :i* sells oranges1 lemons1 grape fruit1 etc4 ,! color implication is obvi\s47 ,if ! jewel] /ill wi%es to use ! t]m topaz because ( ! famili>ity ( ! public ) t "n1 !n he %\ld at lea/ qualify x 9 "s way4 ,"o "n t is curr5t = t purpose is ,spani% topaz1 ano!r is ,qu>tz-topaz4 ,p]haps ! latt] is ! lea/ objectionable ( ! names t include ! ^w topaz4 ,"s ( ! w9e yell[ true topazes lose ! yell[1 b reta9 ! p9k compon5t1 on be+ g5tly heat$4 ,! result+ p9k /one is r pretty & usually comm&s a high] price ?an ! yell[ topazes4 ,su* artificially alt]$ topazes %\ld be sold only = :at !y are1 & probably ! "n p9k$ topaz1 imply+1 z x does1 t some?+ has be5 done to ! /one1 is z good a "n z any4 ,!re is1 h[ev]1 little *ance ( fraud 9 ?is connection1 z natural p9k topazes are n se5 9 ! trade1 be+ v r>e4 ,"s blui%-gre5 topaz is said to be sold z aquam>9e1 & ?is confusion ( species & ( names %\ld1 ( c\rse1 be /opp$ by an actual det]m9ation ( ! mat]ial z to its prop]ties4 ,lack+ a refractomet]1 ! widely diff]+ specific gravities ( ! two m9]als w\ld easily s]ve to di/+ui% !m4 ,,lesson ,,xx ,,! ,,nam+ ,,( ,,preci\s ,,/ones 7,conclud$7 ,,b]yl1 ,,em]ald1 ,,aquam>9e4 ,com+ n[ to b]yl we h fir/ em]ald1 !n aquam>9e1 !n b]yls ( o!r colors to consid]4 ,!re is too (t5 a t5d5cy among deal]s to confuse v>i\s gre5 /ones1 & ev5 d\blets1 "u ! "n em]ald4 ,:ile ! price *>g$ usually be>s a fair relation to ! value ( ! mat]ial furni%$1 x w\ld be bett] to (f] t\rmal9e1 or p]idot 7! m9]al "n ( :i* is oliv9e71 or demantoid g>net 7sometimes wrongly call$ ,oliv9e71 or em]ald d\blets1 or em]ald or imitation em]ald1 z ! case might be1 "u _! own names4 ,!re are no true syn!tic or sci5tific or recon/ruct$ em]alds1 & none ( ^! t]ms %\ld be us$ by ! trade4 ,!re has be5 an ef=t made 9 "s cases to d bus9ess ^u ! good reputation ( ! sci5tific rubies & sapphires1 b ! products (f]$1 :5 n out & out glass imitations1 h usually be5 d\blets or triplets1 consi/+ p>tly ( "s pale1 inexp5sive1 natural m9]al1 su* z qu>tz or b]yl1 & a lay] ( deep gre5 glass to give ! :ole a prop] color4 ,all attempts to melt real em]ald or b]yl h yield$ only a b]yl glass1 s(t] & light] ?an true em]ald1 & n cry/all9e1 b r glassy 9 /ructure4 ,h5ce ! names recon/ruct$1 syn!tic & sci5tific %\ld nev] be appli$ to em]ald4 ,! light gre5 & blue gre5 b]yls are correctly call$ aquam>9es1 ! pale sky-blue b]yls %\ld be nam$ simply blue b]yl4 ,yell[ b]yl may be call$ gold5 b]yl1 or x may be call$ heliodor1 a "n t 0 devis$ = ! f9e yell[ b]yl ( ,madagasc>4 ,beautiful p9k b]yl f ,madagasc> has be5 call$ morganite1 a "n t des]ves to live 9 ord] to commemorate ! great int]e/ tak5 by ,j4 ,pi]pont ,morgan 9 collect+ & cons]v+ = future g5]ations _m ( ! gems 9 ! ,am]ican ,museum ( ,natural ,hi/ory 9 ,new ,york4 ,,zircon4 ,we n[ come to a numb] ( m9]als slightly less h>d ?an b]yl1 b h>d] ?an qu>tz1 & zircon is p]haps z h>d z any ( ^!1 s x w be consid]$ next4 ,r$ zircon1 :i* is r>e1 is prop]ly call$ hyac9?4 ,_m ,hessonite g>nets 7c9namon /ones7 are incorrectly call$ hyac9?s1 h[ev]4 ,! true hyac9? has m snap & fire ow+ to its adamant9e surface lu/] & high disp]sive p[]1 z well z to its high refractive index4 ,a true hyac9? is a beautiful /one4 ,gold5 yell[ zircons are correctly call$ jac9?s4 ,artificially :it5$ zircons 7! color ( :i* has be5 remov$ by heat+7 are kn[n z j>goons or sometimes z ,matura diamonds4 ,all o!r colors 9 zircon %\ld be nam$ simply zircon1 ) a color adjective to indicate ! p>ticul> color z1 br[n zircon1 etc4 ,,t\rmal9e4 ,t\rmal9e furni%es gems ( _m diff]5t colors4 ,^! are all usually call$ simply t\rmal9e1 ) a color adjective to specify ! p>ticul> color1 z1 = example1 ! p9k t\rmal9e ( ,cali=nia4 ,r$ t\rmal9e is1 h[ev]1 sometimes call$ rubellite1 & :ite t\rmal9e has be5 call$ a*roite4 ,! latt] mat]ial is seldom cut1 & h5ce ! "n is seldom se5 or us$4 ,,g>net4 ,we may next consid] ! g>nets1 z mo/ ( !m are some:at h>d] ?an qu>tz4 ,z 0 said 9 ,lesson ,,xviii4 9 our /udy ( m9]al species1 !re are sev]al types ( g>nets1 *>act]iz$ by simil>ity ( *emical composition1 or at lea/ by analogy ( composition1 b1 hav+ specific diff]5ces ( prop]ty4 ,! names us$ by jewel]s = ! sev]al types ( g>nets ought to be a fairly true indication z to ! type 9 h& 9 a p>ticul> case4 ,at pres5t !re is consid]able confusion 9 ! nam+ ( g>nets4 ,! mo/ common practice is to call all g>nets ( a purpli%-r$ color alm&9es4 ,z _m su* g>nets belong to ! m9]al species alm&ite g>net1 !re is little objection to ! cont9uance ( ?is practice4 ,! some:at less d5se1 & less h>d blood r$ g>nets are prop]ly call$ pyrope g>nets 7lit]ally fire g>nets74 ,_m ( ! ,arizona g>nets belong 9 ?is division4 ,! t]m ,arizona rubies %\ld n be us$4 ,z 0 said "u ruby1 no?+ b r$ corundum %\ld receive t title4 ,simil>ly ! pyrope g>net ( ! diamond m9es ( ,s\? ,africa is incorrectly call$ ,cape ruby4 ,pyrope & alm&ite g>net t5d to m]ge 9 composition & 9 prop]ties1 & ! beautiful ,rhodolite g>nets ( ,macon ,c\nty1 ,nor? ,c>ol9a1 are betwe5 ! two v>ieties 9 composition1 9 color1 & 9 o!r prop]ties4 ,hessonite g>net furni%es yell[i%-r$ & br[ni%-r$ /ones1 :i* are sometimes also call$ c9namon /ones4 ,!y are also frequ5tly & incorrectly call$ jac9? or hyac9?1 t]ms :i*1 z we h se51 %\ld be res]v$ = yell[ & r$ zircon1 respectively4 ,&radite g>net furni%es brilliant gre5 /ones1 :i* h be5 incorrectly nam$ ,oliv9es by ! trade4 ,! "n is un=tunate z x is id5tical ) ! true "n ( ! m9]al :i* gives u p]idot4 ,! "n does n ev5 sugge/ ! color ( ^! g>nets correctly1 z !y are seldom olive gre5 9 %ade4 ,z ! sc>city ( f9e specim5s & _! great beauty make a fairly high price necess>y1 ! public w\ld h>dly pay x = any?+ t 0 call$ g>net1 z g>nets are reg>d$ z common & *eap4 ,p]haps ! adoption ( ! "n ,demantoid might relieve ! situation4 ,! /ones are frequ5tly ref]r$ to z demantoid g>nets on acc\nt ( _! diamond-l lu/] & disp]sion4 ,! use ( demantoid alone1 if a n\n may be made f ! adjective1 w\ld avoid bo? ! confusion ) ! m9]al oliv9e1 & ! *eap5+ effect ( ! ^w g>net1 & w\ld at ! same "t sugge/ "s ( ! mo/ /rik+ prop]ties ( ! mat]ial4 ,spodum5e furni%es p9k to lilac ,kunzite1 nam$ aft] ,dr4 ,george ,f4 ,kunz1 ! gem exp]t1 & = a "t an em]ald gre5 v>iety 0 _h f ,nor? ,c>ol9a :i* became kn[n z ,hidd5ite1 aft] its discov]]1 ,w4 ,e4 ,hidd54 ,no confusion ( nam+ seems to h aris5 9 reg>d to ?is m9]al4 ,! next m9]al 9 ! scale ( h>dness is qu>tz4 7,h>dness #g47 ,:5 pure & colorless x %\ld be call$ rock cry/al4 ,purple qu>tz is ( c\rse ame?y/4 ,"s deal]s h adopt$ a bad practice ( call+ ! f9e deep purple ame?y/ ,ori5tal ame?y/1 :i* %\ld n be done1 z ! t]m ,ori5tal has = a long "t signifi$ a corundum gem4 ,z ,sib]ia has produc$ "s v f9e ame?y/s1 ! t]m ,sib]ian ame?y/ w\ld be a good "o to designate any especially f9e gem4 ,,qu>tz ,,gems4 ,we h already consid]$ ! nam+ ( yell[ qu>tz 9 connection ) topaz4 ,citr9e qu>tz is probably ! be/ "n = ?is mat]ial4 ,if x is felt t ! "n topaz mu/ be us$1 ! prefix qu>tz %\ld be us$1 or p]haps ,spani% topaz w d1 b "s ef=t %\ld be made to di/+ui% x f ! true preci\s topaz4 ,9 addition to ame?y/ & citr9e qu>tz we h ! p9ki%1 milky qu>tz kn[n z rose qu>tz4 ,?is is usually correctly nam$4 ,cat's-eye is a t]m t %\ld be res]v$ = ! ,*rysob]yl v>iety1 & ! qu>tz v>iety %\ld always be call$ qu>tz cat's-eye4 ,tig]'s-eye is a m9]al 9 :i* a s(t fibr\s mat]ial has be5 dissolv$ away1 & qu>tz has be5 deposit$ 9 its place4 ,av5tur9e qu>tz is ! correct "n = qu>tz conta9+ spangles ( mica4 ,cle>1 colorless pebbles ( qu>tz are sometimes cut = t\ri/s4 ,su* pebbles are frequ5tly misnam$ diamonds ) "s prefix1 z = example ,lake ,george diamonds1 etc4 ,among ! m9utely cry/all9e v>ieties ( qu>tz we h ! cle> r$1 :i* %\ld be call$ c>nelian1 ! br[ni%-r$ s>d1 ! gre5 *rysoprase1 ! leek gre5 prase1 & ! bright] gre5 plasma4 ,! la/ ?ree are n s commonly se5 z ! fir/ two1 & frequ5tly ! be/-color$ specim5s are artificially dy$4 ,jasp]1 a mat]ial m highly reg>d$ by ! anci5ts ?an at pres5t1 is ma9ly qu>tz1 b conta9s en\gh e>?y mat]ial to make x opaque4 ,blood/one is a gre5i% *alc$ony ) spots ( r$ jasp]4 ,agates are b&$ *alc$onies1 ! v>iety call$ onyx hav+ v regul> b&s1 & ! s>donyx be+ an onyx agate 9 :i* "s ( ! b&s are ( r$di% s>d4 ,j z we consid]$ opal ) qu>tz 7because ( its *emical simil>ity7 :5 discuss+ m9]al species1 s we may n[ consid] ! prop] nam+ ( opals "h4 ,preci\s opal is di/+ui%$ f common opal by ! beauty ( its display r ?an by any diff]5ce 9 composition4 ,! effect is ( c\rse due to ! exi/5ce ( ?9 films 7probably ( mat]ial ( slightly diff]5t d5sity71 fill+ :at once 7 cracks 9 ! mass4 ,! ra9b[ colors are ! result ( int]f]5ce ( light 7see a college text on physics = an explanation ( int]f]5ce74 ,! v>y+ ?ickness ( ^! films gives v>y+ colors1 s diff]5t specim5s ( opal %[ v diff]5t effects4 ,! diff]5ces ( di/ribution ( ! films )9 ! mat]ial also cause v>iations 9 ! effects4 ,h5ce we h h>dly any two specim5s ( opal t are alike4 ,!re are1 h[ev]1 c]ta9 fairly def9ite types ( opal & jewel]s %\ld le>n to apply correct names to ^! types4 ,mo/ prom95t among ! opals ( to-day are ! s-call$ ,black opals f ,new ,s\? ,wales4 ,^! give vivid fla%es ( color out ( seem+ d>kness4 ,9 "s positions ! /ones1 z ! "n implies1 appe> blue-black or blacki% gray4 ,by transmitt$ light1 h[ev]1 ! blui% /ones appe> yell[4 ,ow+ to ! %>p contra/ betwe5 ! d>k backgr\nd & ! fla%+ spectrum colors1 black opals are mo/ attractive /ones & f9e specim5s comm& high prices4 ,"o f9e piece1 :i* 0 on exhibition at ! ,panama-,pacific ,exposition 0 9 ! %ape ( an elongat$ %ield1 ab\t #a-c_/d in*es by #a-a_/h in*es 9 size & r flat & ?9 = its spread4 ,x gave 9 "o position a solid surface ( almo/ pure ruby r$ :i* *ang$ to gre5 on tipp+ ! /one to ! opposite direction2 #b1jjj 0 ask$ = ! piece4 ,:ite opal is ! "n appli$ to ! light] %ades ( opal :i* d n %[ ! blui%-black effect 9 any position4 ,h>lequ9 opal has r l>ge areas ( def9ite colors giv+ some:at ! effect ( a map ( ! ,unit$ ,/ates 9 :i* ! diff]5t ,/ates are 9 diff]5t colors4 ,fire opal is an orange-r$ v>iety4 ,x has "s play ( colors 9 addition to its orange-r$ body color4 ,opal ,matrix has t9y specks & films ( preci\s opal di/ribut$ ?r\gh a d>k volcanic rock & ! mass is %ap$ & poli%$ z a :ole4 ,,jade4 ,jade %\ld next receive att5tion4 ,x is a mu* abus$ t]m4 ,"u x "o may pur*ase jadeite1 nephrite1 b[5ite1 amazonite1 or frequ5tly simply gre5 glass4 ,! use ( ! ^w ought to be conf9$ to ! fir/ two m9]als m5tion$1 namely1 jadeite & nephrite1 = !y only possess ! extreme t\ghness toge!r ) consid]able h>dness t we expect ( jade4 ,b[5ite1 :ile t\gh1 is relatively s(t & amazonite is brittle & also easily cleavable1 :ile glass is bo? s(t & brittle4 ,,p]idot ,,& ,,oliv9e4 ,! m9]al oliv9e gives u ! p]idot 7?is "n %\ld be kept = ! deep] bottle gre5 /ones71 & ! olive gre5 gems ( ?is same m9]al may correctly be call$ oliv9e or *rysolite4 ,z 0 expla9$ "u g>net1 jewel]s frequ5tly use ! t]m oliv9e to designate demantoid g>net4 ,! t]m *rysolite is also sometimes incorrectly us$ = ! gre5i%-yell[ *rysob]yl4 ,,feldsp> ,,gems4 ,among ! m9]als s(t] ?an qu>tz1 :i* are us$ z gems1 we h also feldsp>1 :i* gives u moon/one1 ,labradorite1 & ,amazonite4 ,an opalesc5t =m ( *alc$ony is frequ5tly ga!r$ on ,cali=nia bea*es & poli%$ = t\ri/s "u ! "n ( ,cali=nia ,moon/one4 ,?is "n is un=tunately *os5 z ! mat]ial is n ! same z t ( true moon/one & ! effect is n s pron\nc$ or s beautiful4 ,! poli%$ /ones %[ m]ely a milky cl\d9ess )\t any ( t beautiful %e5 ( ! true moon/one4 ,labradorite is usually correctly nam$4 ,amazonite 0 orig9ally misnam$1 z none is f\nd along ! riv] ( t "n4 ,! t]m has come into su* g5]al use1 h[ev]1 t we %all probably h to cont9ue to use x1 especially z no o!r "n has come into use = ?is blui%-gre5 feldsp>4 ,z has already be5 said1 amazonite is sometimes sold z jade1 :i* is incorrect4 ,,mala*ite1 ,,azurite1 ,,& ,,lapis ,,lazuli4 ,mala*ite & azurite are usually correctly nam$1 b lapis lazuli is a "n t is frequ5tly misus$1 be+ appli$ to crackl$ qu>tz t has be5 /a9$ ) ,prussian blue1 or "s o!r dye1 to an unconv9c+ resemblance to true lapis4 ,su* artificially produc$ /ones are sometimes sold z ,swiss lapis4 ,!y are h>d] ?an true lapis & probably we> mu* bett] 9 expos$ ornam5ts1 b !y are n lapis & are nev] ( equal color1 & names %\ld n be misus$1 & especially is ?is true 9 a trade :]e ! public has _h to rely s completely ^u ! k & ! integrity ( ! deal]4 ,) ! increase ( k ab\t preci\s /ones t is sl[ly b /eadily gr[+ among ! public1 x becomes m ?an ev] necess>y = ! jewel] & gem deal] to "k & to use ! correct names = all preci\s /ones4 ,! /ud5t :o wi%es to le>n m ab\t ! matt] w h to cull 8 in=mation f _m diff]5t works on gems4 ,g4 ,f4 ,h]b]t-,smi?1 9 8 ,gem-,/ones1 gives a ?ree & "o half page *apt] on ,nom5clature ( ,preci\s ,/ones 7,*ap4 ,,xiii41 pp4 #aji-aab74 ,! pres5t lesson has attempt$ to br+ toge!r 9 "o place mat]ial f _m s\rces1 toge!r ) "s sugge/ions f ! au?or4 ,,lesson ,,xxi ,,:]e ,,preci\s ,,/ones ,,are ,,f\nd ,,occurr5ce ,,( ,,diamond4 ,e deal] 9 preci\s /ones %\ld "k some?+ ( ! s\rces ( ! gems t he sells4 ,! mann] ( ! occurr5ce ( ! r\gh mat]ial is also a matt] ( int]e/4 ,x w !re=e be ! purpose ( ?is lesson to give a brief acc\nt ( ! geographical s\rces ( ! pr9cipal gems & ( _! mode ( occurr5ce 9 ! e>?4 ,= ! sake ( uni=mity ( treatm5t we w once m foll[ ! desc5d+ ord] ( h>dness among ! gems & we ?us beg9 by describ+ ! occurr5ce ( diamond4 ,x w be ( int]e/ to note fir/ t ! e>lie/ s\rce ( ! diamond 0 ,india1 & t = _m ye>s ,india 0 almo/ ! sole s\rce4 ,tav]ni] tells u t ! diamond m9+ indu/ry 0 9 a ?riv+ /ate dur+ ! ye>s f #afdj to #afhj1 dur+ :i* "t he made six j\rneys to ,india to pur*ase gems4 ,he speaks ( ,borneo z ano!r s\rce ( diamonds1 b mo/ ( ! diamonds ( t "t 7 furni%$ by ,india4 ,,golcondas4 ,indian diamonds 7 notewor?y = _! magnific5t /eely blue-:ite quality & _! great h>dness1 & occasionally "o comes on ! m>ket to-day ) an au!ntic p$igree1 trac+ its orig9 back to ! old ,indian m9es1 & su* /ones usually comm& v high prices4 ,"o ( a little ov] sev5 & "o half c>ats 9 weight1 9 ! =m ( a p]fect drop brilliant1 has lately be5 (f]$ = sale at a price n f> f #a1jjj p] c>at4 ,su* diamonds are sometimes call$ ,golcondas because "o ( ! m9+ di/ricts f :i* ! f9e l>ge ,indian /ones came 0 ne> ! place ( t "n4 ,"s ( ! /ones f ! ,jg]sfonte9 m9e 9 ,s\? ,africa resemble ! ,golcondas 9 quality4 ,_m ( ! l>ge hi/orical cr[n diamonds ( ,europe came f ! ,indian m9es4 ,! /ones 7 f\nd 9 a s$im5t>y mat]ial1 a sort ( conglom]ate1 9 :i* !y1 toge!r ) _m o!r cry/all9e mat]ials1 _h become imprison$4 ,_! orig9al s\rce has nev] be5 det]m9$4 ,!y are !re=e ( ! s-call$ ,riv] type ( /one1 hav+ probably be5 transport$ f _! orig9al matrix1 aft] ! dis9tegration ( ! latt]1 to new places ( deposit1 by ! c>ry+ p[] ( riv] wat]s4 ,! ,indian m9es n[ yield v few /ones4 ,! ,unit$ ,/ates ,consul> reports occasionally m5tion ! f9d+ ( a few scatt]$ cry/als b ! ri* deposits 7 app>5tly work$ out dur+ ! sev5te5? c5tury & ! e>ly "p ( ! eighte5? c5tury4 ,9 #agbe & 9 ! few foll[+ ye>s ! ,brazilian diamond fields began to sup]s$e ^? ( ,india4 ,l ! latt]1 ! ,brazilian fields 7 alluvial1 t is1 ! mat]ials 7 deposit$ by riv] action aft] hav+ be5 c>ri$ to "s di/ance f _! orig9al s\rces4 ,,brazilian ,,diamonds4 ,! diamonds ( ,brazil also resembl$ ^? ( ,india 9 quality1 be+ on ! av]age bett] ?an ^? ( ! pres5t ,s\? ,african m9es4 ,x may be add$ t ev5 ! ,african diamonds t are f\nd 9 riv] digg+s av]age bett] 9 quality ?an ^? ( ! volcanic pipes :i* =m ! pr9cipal s\rce ( ! _w's supply to-day4 ,!re seems to be a sup]abundance ( iron oxide 9 ! rocks ( ! ,african m9es & 9 ! diamonds !mselves1 imp>t+ yell[ or br[ni% t9ts to ! mat]ial4 ,! ,riv] /ones seem to h lo/ ?is color to a consid]able ext5t1 if !y ev] _h x4 ,possibly long extraction ) wat] has remov$ ! v slightly soluble color+ mat]ial4 ,:atev] ! cause ( _! sup]iority ,riv] /ones h always be5 m highly reg>d$ ?an /ones f ! volcanic pipes4 ,brazil furni%$ ! _w's pr9cipal supply ( diamonds until ! discov]y ( ! ,african /ones 9 #ahfg4 ,at pres5t relatively small numb]s ( ,brazilian /ones rea* ! _w's m>kets4 ,mo/ ( ^! come f ! great ,bahia di/rict 7discov]$ 9 #ahdd7 r ?an f ! old] m9es ( ,brazil4 ,! pres5t ,brazilian /ones av]age ( small size4 ,!y are1 h[ev]1 ( v good quality z a rule4 ,a few gre5 /ones are f\nd 9 ,brazil & ^! may be ( an abs9!-gre5 or ( a pi/a*io-gre5 t9t4 ,,au/ralian ,,& ,,am]ican ,,s\rces4 ,:ile a few diamonds n[ come on ! m>ket f ,new ,s\? ,wales1 & :ile an occasional /one is f\nd 9 ! ,unit$ ,/ates 7usually 9 glacial drift 9 ! nor? c5tral ,/ates1 or 9 volcanic mat]ial some:at resembl+ t ( ,s\? ,africa 9 ,arkansas7 yet ! _w's output n[ comes almo/ entirely f ,s\? ,africa & ma9ly f ! enorm\s volcanic pipes ( ! ,kimb]ly di/rict & ^? ( ! ,premi] ,co4 9 ! ,transvaal4 ,,s\? ,,african ,,diamonds4 ,! nature ( ! occurr5ce ( diamond 9 ! pipes ( ,s\? ,africa is s well kn[n to all :o deal 9 diamonds to-day t b little space ne$ be devot$ to x4 ,! blue gr\nd1 z ! rock 9 :i* ! diamonds are f\nd is call$1 seems to h be5 =c$ up f bel[1 p]haps z ! mat]ial ( a mud volcano1 br++ ) x ! diamonds1 g>nets1 zircons1 & ! fifty or m o!r m9]als t h be5 f\nd 9 ! blue gr\nd4 ,! fragm5t>y "* ( "s ( ^! m9]als w\ld indicate t ! blue gr\nd 0 n _! orig9al matrix4 ,h[ ! diamonds orig9ally cry/alliz$ & :]e1 is /ill probably a matt] = fur!r speculation4 ,:ile at fir/ ! m9es 7 work$1 l qu>ries1 f ! surface1 & :ile ! great ,premi] m9e is /ill s work$1 mo/ ( ! pres5t m9es are work$ by s9k+ %afts 9 ! native rock outside ( ! blue gr\nd & !n tunnel+ into ! diamond-be>+ rock lat]ally1 remov+ x to ! surface1 all[+ x to wea!r on ! floors until x crumbles1 !n cru%+ & wa%+ x & conc5trat+ ! heavy m9]als by gravity me?ods4 ,l>ge diamonds are !n pick$ out ( ! conc5trates by h& & small ones & fragm5ts are remov$ by ! greas]s1 :i* are %ak+ tables heavily sme>$ ) grease ov] :i* ! conc5trates are wa%$ & to :i* diamond alone1 ( all ! m9]als 9 ! conc5trate1 /icks4 ,! grease is p]iodically remov$ & melt$1 & ! diamonds secur$4 ,! grease c !n be us$ aga94 ,g]man ,s\? ,we/ ,africa furni%es a consid]able output ( v small diamonds1 :i* are f\nd 9 dry s& f> f any pres5t riv]s4 ,^! diamonds cut to spl5did :ite melee & ! output is l>ge en\gh to make "s diff]5ce 9 ! relative price ( small /ones z comp>$ to l>ge ones4 ,! ,s\? ,we/ ,african field seldom yields a /one t w af=d a f9i%$ qu>t]-c>at diamond4 ,,rubies4 ,pass+ on to ! occurr5ce ( ! corundum gems we w consid] fir/ ! ruby4 ,mo/ f9e rubies come f ,burmah4 ,! di/rict 9 :i* !y are f\nd is ne> ,mogok4 ,practically all ! f9e pigeon-blood rubies come f ?is di/rict4 ,! fa%ion = r$ /ones be+ = ! "t little 9 evid5ce rubies are n n[ 9 great dem&4 ,?is cessation ( dem& c h>dly be laid to ! competition ( ! sci5tific ruby1 = ! sapphire is n[ v mu* 9 vogue1 yet sci5tific sapphires resemble ! natural ones ev5 m closely ?an d ! rubies4 ,siam furni%es a consid]able numb] ( d>k g>net-l rubies4 ,^! d n comm& high prices4 ,!y are1 h[ev]1 sometimes v beautiful1 especially :5 well cut = brilliancy1 & :5 9 a /rong light4 ,ceylon furni%es a few rubies & a few r$ corundums h be5 f\nd 9 ,nor? ,c>ol9a4 ,! ,burmese rubies appe> to h be5 =m$ 9 a lime/one matrix1 b mo/ ( ^? obta9$ are gott5 f ! /ream b$s1 :]e !y h be5 c>ri$ by wat] aft] wea!r+ out f ! "m rock4 ,! rubies ( ,ceylon1 too1 probably orig9at$ 9 a lime/one matrix1 b are s\ght 9 /ream gravels4 ,,sapphires4 ,f9e blue sapphires orig9ate 9 ,siam 9 l>g] numb]s ?an 9 any o!r locality4 ,ka%mir1 9 ,india1 also supplies spl5did specim5s ( l>ge size4 ,ceylon1 too1 furni%es a good deal ( sapphire1 b mo/ly ( a light] color ?an ! ,ka%mir sapphire4 ,! ,ceylon sapphires are f\nd 9 ! /reams1 b orig9ate 9 rock ( igne\s orig94 ,montana furni%es consid]able quantities ( sapphire1 "s ( :i* is ( v good color4 ,x is1 ( c\rse1 z good z ! ,ori5tal if ( equal color1 be+ ( ! same mat]ial4 ,! bett] color$ sapphire f ,montana is m9$ f ! rock4 ,mo/ ( ! sapphires f\nd 9 ! riv] gravels ne> ,hel5a1 ,mont41 are gre5i% blue or ( o!r colors1 & n ( f9e blue4 ,que5sl& & ,victoria 9 ,au/ralia supply consid]able quantities ( sapphire4 ,:5 blue ! ,au/ralian sapphire is usually too d>k to be v valuable4 ,! gold5 & o!r fancy sapphires ( ! trade come l>gely f ! ,ceylon gravels4 ,siam yields silky br[n /ones & "s f9e gre5 ones4 ,"s ( ! ,au/ralian sapphires :5 cut 9 c]ta9 directions yield gre5 /ones4 ,,*rysob]yl4 ,*rysob]yl ( ! v>iety ,alex&rite n[ comes ma9ly f ,ceylon1 al?\gh =m]ly f ! ,ural ,m\nta9s4 ,! cat's-eyes also come *iefly f ,ceylon4 ,! yell[i%-gre5 *rysob]yls 7:i* jewel]s sometimes call *rysolite7 come bo? f ,ceylon & f ,brazil4 ,!y are frequ5tly f\nd 9 pap]s ( fancy sapphires or fancy color /ones1 s call$4 ,,sp9el4 ,sp9els are f\nd along ) ruby 9 ,burmah & 9 ,siam & !y also occur 9 ! gem gravels ( ,ceylon4 ,lime/one is ! usual matrix ( sp9el1 al?\gh x is m (t5 m9$ 9 gravels result+ f ! wea!r+ ( ! matrix4 ,,topaz4 ,true topaz1 ( w9e-yell[ color1 comes mo/ly f ,brazil4 ,ceylon also furni%es yell[ topaz4 ,asiatic ,russia furni%es f9e l>ge blue or blue-gre5 cry/als resembl+ aquam>9e 9 appe>ance4 ,mo/ ( ! topaz f\nd 9 o!r localities is pale or colorless4 ,sev]al ( our we/]n ,/ates1 notably ,utah1 ,colorado1 & ,cali=nia1 furni% colorless topaz4 ,mexico & ,japan also produce x4 ,x is seldom cut1 =1 :ile produc+ a r brilliant /one1 x has little fire & is !re=e n v attractive4 ,,em]ald ,,& ,,aquam>9e4 ,b]yl ( ! em]ald v>iety is exce$+ly sc>ce 9 ! e>?4 ,mo/ ( ! be/ em]ald comes f ,colombia1 ,s\? ,am]ica4 ,l>ge cry/als ( pal] color come f ! ,urals4 ,l ruby & sp9el1 em]ald usually orig9ates 9 lime/one4 ,"o is tempt$ to suspect t ^! /ones are ( aque\s orig9 & t sapphires1 & b]yl1 o!r ?an em]ald1 are m likely ( igne\s orig94 ,b]yls ( ! aquam>9e type occur 9 _m places1 b usually ( too pale a t9t1 or too imp]fect1 to be wor?y ( cutt+4 ,f9e gem b]yl ( blue & blue-gre5 t9ts comes f ,sib]ia & f sev]al places 9 ! ,ural ,m\nta9s on _! ,asiatic slopes4 ,! ,m9as ,g]aes di/rict ( ,brazil1 fam\s = all k9ds ( gem /ones1 furni%es mo/ ( ! aquam>9e ( comm]ce4 ,! pegmatite dikes ( ,haddam ,neck1 ,conn41 ( ,/oneham1 ,me41 & ( ,san ,diego ,c\nty1 ,cal41 h furni%$ spl5did aquam>9e & o!r b]yl4 ,^! dikes1 accord+ to ! geological evid5ce1 are ! result ( ! comb9$ action ( heat & wat]4 ,?us bo? melt+ & dissolv+ w5t on toge!r & z a result _m f9e gem m9]als ( magnific5t cry/allization 7 =m$ dur+ ! subsequ5t cool+4 ,! long] ! cool+ la/$ & ! m free space = gr[? ! cry/als _h1 ! l>g] & m p]fect !y got4 ,! au?or has himself obta9$ f9ely cry/alliz$ aquam>9e & t\rmal9e f ! ,haddam1 ,conn41 locality & ! be/ specim5s !re occur 9 pockets or cavities 9 ! co>se granite4 ,)91 ^! pockets are l9$ ) cry/als ( smoky qu>tz1 t\rmal9e1 b]yl1 & o!r m9]als4 ,sometimes cry/als occur 9 mud or clay masses inside ! cavities & su* cry/als1 hav+ be5 free to gr[ un9t]rupt$ly 9 e direction1 7 p]fect 9 =m1 be+ d\bly t]m9at$1 & n atta*$ any:]e to ! rock4 ,madagasc> has 9 rec5t ye>s furni%$ ! f9e/ p9k b]yl1 :i* has be5 nam$ ,morganite4 ,yell[ b]yl 7,heliodor7 & aquam>9e also occur 9 ,madagasc>4 ,,zircon4 ,zircon comes on ! m>ket ma9ly f ,ceylon4 ,x des]ves to be z mu* e/eem$ 9 ?is c\ntry z x is 9 ,ceylon1 = its optical prop]ties are su* t x is a v snappy /one4 ,"s ( ! colors 9 :i* x occurs1 su* z ! gold5 br[ns1 l5d !mselves nicely to ! mat*+ ( gems & g>m5ts1 &1 ) ! gr[? ( education 9 su* matt]s1 jewel]s w\ld d well to get bett] acqua9t$ ) ! possibilities ( zircon & to introduce x to _! cu/om]s4 ,! supply f ,ceylon is suffici5t to ju/ify popul>iz+ ! /one4 ,small zircons are f\nd 9 almo/ e heavy conc5trate1 z1 = example1 9 ! conc5trates ( ! diamond m9es ( ,s\? ,africa1 & 9 ^? ( gold plac]s 9 _m places4 ,! r\gh /ones resemble r\gh diamonds 9 lu/] & are sometimes mi/ak5 = diamonds4 ,,g>nets4 ,g>nets ( v>i\s types are f\nd widely di/ribut$ 9 nature4 ,p]haps ! ,bohemian supply is be/ kn[n1 hav+ furni%$ a ho/ ( small /ones :i* h usually be5 rose cut = clu/] "w or made into beads4 ,! ,bohemian g>nets are ( ! pyrope or fire-r$ type4 ,relatively few l>ge /ones ( suffici5t transp>5cy = cutt+ are produc$ 9 ! ,bohemian m9es4 ,! s-call$ ,cape rubies ( ! diamond m9es ( ,s\? ,africa are pyrope g>nets & "s l>ge & f9e ones are f\nd4 ,! ,arizona rubies are pyrope g>nets1 & :ile seldom ( notable size1 "s are ( v f9e color1 approa*+ deep rubies1 & ! color rema9s attractive by artificial light4 ,alm&ite g>net1 ! alm&9e ( ! jewel] is less abundant ?an pyrope1 :5 ( gem quality4 ,ceylon furni%es "s & ,india furni%es p]haps m4 ,brazil1 f its prolific gem gravels at ,m9as ,novas1 supplies good alm&ite1 & small] quantities are f\nd 9 _m diff]5t localities4 ,hessonite g>net1 ! c9namon /one or hyac9? 7incorrect7 ( ! trade1 comes ma9ly f ,ceylon4 ,&radite g>net1 ( ! v>iety kn[n z demantoid1 f its diamond-l prop]ties1 & :i* is usually sold "u ! mislead+ "n oliv9e 9 ! trade1 comes f ! we/]n slopes ( ! ,ural ,m\nta9s4 ,,t\rmal9e4 ,gem t\rmal9e comes f ,ceylon1 f ,madagasc>1 f ! ,ural ,m\nta9s1 f ,brazil1 f ,ma9e1 f ,connecticut1 & f ,cali=nia4 ,! ,ceylon t\rmal9es are mo/ly yell[ or yell[i% gre51 sometimes f9e olive-gre54 ,^? f ! ,urals may be p9k1 blue or gre54 ,brazilian t\rmal9es are usually gre51 b sometimes r$4 ,9 fact 9 _m localities sev]al colors ( t\rmal9e are usually f\nd toge!r & x may be t a s+le cry/al w be gre5 9 mo/ ( its l5g? b r$ or p9k tipp$4 ,"s cry/als h a p9k core & a gre5 ext]ior4 ,! au?or has f\nd bo? ( ! two latt] types 9 ! ,haddam1 ,conn41 t\rmal9es1 & on "o occasion 0 surpris$ to get back a w9e-color$ t\rmal9e f a cutt] to :om he _h s5t a gre5 cry/al4 ,!re 0 b a ?9 %ell ( ! gre5 mat]ial on ! outside ( ! cry/al4 ,"s ( ! ,madagasc> t\rmal9e is ( a f9e br[ni% r$1 almo/ z deep z a light g>net1 & mu* cle>] ?an mo/ g>net4 ,w\ld x n be fitt+ on acc\nt ( its occurr5ce 9 sev]al localities 9 ! ,unit$ ,/ates1 = ,am]icans to use m t\rmal9e 9 _! jewels8 ,! quality ( "s ( ! t\rmal9es ( ,ma9e1 & ( ,cali=nia especially1 is n excell$ by t\rmal9e f any o!r locality4 ,"s ( ! ,ma9e t\rmal9e is ( a delightful1 slightly blui%-gre5 t9t t almo/ approa*es em]ald4 ,,kunzite4 ,spodum5e1 ( ! v>iety kunzite1 comes f ,san ,diego ,c\nty1 ,cali=nia4 ,,qu>tz ,,gems4 ,com+ n[ to ! qu>tz gems we f9d ame?y/ & citr9e1 or gold5 qu>tz widely di/ribut$ s t only ! localities t furni% ! bett] grades ( ^! /ones ne$ be m5tion$4 ,sib]ia & ,uruguay furni% f9e ame?y/4 ,brazil also furni%es l>ge quantities ( v good quality4 ,,ame?y/4 ,! *ief *>m ( ! ,sib]ian ame?y/ lies 9 its l>ge r$ compon5t1 :i* enables x to *ange f a deep grape-purple by daylight to a f9e r$ by artificial light t is ri* 9 r$ rays1 & poor 9 blue ones4 ,! pal] types ( ame?y/s t 7 once e/eem$1 probably = lack ( ! ri* deep v>iety1 become gray 9 appe>ance & mu* less lovely "u artificial light4 ,india furni%es "s ame?y/s1 & pap]s ( fancy color /ones conta9+ native cut gems f ,ceylon1 frequ5tly conta9 ame?y/s1 b ,brazil1 ,uruguay1 & ,sib]ia furni% ! great bulk ( ! /ones t are reg>d$ z *oice to-day4 ,,yell[ ,,qu>tz4 ,citr9e or gold5 qu>tz comes ma9ly f ,brazil4 ,! ,spani% topaz is sometimes ! result ( heat+ smoky qu>tz f ,cordova prov9ce 9 ,spa94 ,our own we/]n m\nta9s furni% consid]able yell[ & smoky qu>tz fit = cutt+4 ,,rose ,,qu>tz4 ,rose qu>tz ( ! f9e/ quality comes f ,s\? ,dakota4 ,bav>ia1 ! ,ural ,m\nta9s1 & ,p>is1 ,ma9e1 h also furni%$ x4 ,,agate4 ,agates ( ! f9e/ types1 su* z c>nelian & s>d1 come pr9cipally f ,brazil & f ,india4 ,,opal4 ,opals n[ come mo/ l>gely f ,au/ralia1 ! ,hung>ian m9es yield+ b few /ones at pres5t4 ,! f9e black opals ( ,new ,s\? ,wales are unsurpass$ by any t h ev] be5 f\nd else:]e4 ,mexico furni%es consid]able opal1 & is notable = its f9e fire opal or *]ry opal4 ,,jade4 ,mo/ ( ! jade ( ! v>iety nephrite t is obta9$ to-day comes f sev]al ( ! prov9ces ( ,*9a or f ,sib]ia or f ,turke/an4 ,a d>k-gre5 nephrite comes f ,new ,zeal&4 ,jade ( ! jadeite v>iety1 :i* is h>d] ?an nephrite & m highly valu$1 is r>e4 ,! be/ specim5s come f ,upp] ,burmah4 ,x is also f\nd 9 ,*9a & 9 ,tibet4 ,,p]idot4 ,p]idot1 & ! bright] oliv9e or *rysolite1 :ile ( ! same m9]al species1 d n seem to occur toge!r4 ,! d>k] bottle-gre5 specim5s come f ! ,isl& ( ,/4 ,john 9 ! ,r$ ,sea4 ,x is said t _m ( ! f9] p]idots n[ available h be5 recut f old /ones m9$ _m ye>s ago4 ,que5sl& supplies light-gre5 *rysolite1 & ,arizona a yell[i%-gre5 v>iety4 ,light-gre5 /ones h be5 f\nd ne> ! ruby m9es ( ,upp] ,burmah4 ,,moon/one4 ,moon/one comes ma9ly f ,ceylon4 ,! native cut specim5s are s5t "h & recut1 z1 :5 native cut1 ! direction ( ! gra9 is seldom correct to produce ! moonlight effect 9 symmetrical fa%ion4 ,! native cutt]s app>5tly try to reta9 all ! size & weight t is possible1 reg>dless ( ! effect4 ,,turquoise4 ,turquoise ( ! f9e/ blue & mo/ compact texture 7& h5ce lea/ subject to color *ange7 comes f ! prov9ce ( ,khorasan 9 ,p]sia4 ,sev]al ( our we/]n /ates supply turquoise ( fair quality1 notably ,new ,mexico1 ,arizona1 ,nevada1 & ,cali=nia4 ,,lapis ,,lazuli4 ,lapis ,lazuli comes f ,afghani/an1 f ,sib]ia1 & f ,s\? ,am]ica4 ,,mala*ite4 ,mala*ite is f\nd 9 _m copp] m9es1 b pr9cipally 9 ^? ( ! ,ural ,m\nta9s4 ,,azurite4 ,azurite is f\nd 9 ! ,arizona m9es & 9 ,*essy1 9 ,france 7h5ce ! "n *essylite1 sometimes us$ in/ead ( azurite74 99 99 99 99 99 ,,ref]5ces4 ,/ud5ts :o wi% to get a full] acc\nt ( ! occurr5ce ( preci\s /ones %\ld run ?r\gh ,g4 ,f4 ,h]b]t-,smi?'s ,gem-,/ones "u ! diff]5t v>ieties4 ,?is "w is ! mo/ rec5t au!ntic "w ( a /rictly sci5tific "*4 ,dr4 ,george ,f4 ,kunz's ,gems & ,preci\s ,/ones ( ,nor? ,am]ica gives a detail$ acc\nt ( all ! f9ds 9 ,nor? ,am]ica up to ! "t ( publication4 ,_m ( ^! are ( c\rse ( little comm]cial importance4 ,! ,m9]al ,res\rces ( ! ,unit$ ,/ates conta9s annually a long acc\nt ( ! occurr5ces ( gem mat]ials 9 ?is c\ntry4 ,a sep>ate pamphlet conta9+ only ! gem portion c be _h gratis f ! (fice ( ! ,unit$ ,/ates ,geological ,survey1 ,wa%+ton1 ,d4 ,c4 ,,lesson ,,xxii ,,h[ ,,r\gh ,,preci\s ,,/ones ,,are ,,cut ,,r\gh ,,preci\s ,,/ones4 ,john ,rusk91 :o _h ! means to acquire "s v f9e natural specim5s ( gem mat]ial 0 ( ! op9ion t man ought n to tamp] ) ! wond]ful cry/als ( nature1 b t r !y %\ld be admir$ 9 ! r\gh4 ,:ile "o c und]/& ,rusk9's viewpo9t1 nev]!less ! art ( man c make use ( ! optical prop]ties ( transp>5t m9]als1 prop]ties no less wond]ful ?an ^? exhibit$ 9 cry/allization1 & inde$ intimately associat$ ) ! latt]1 &1 by %ap+ ! r\gh mat]ial 9 accordance ) ^! optical prop]ties1 greatly enhance ! beauty ( ! gem4 ,no mat]ial illu/rates ! wond]ful improvem5t t may be br\ght ab\t by cutt+ & poli%+ bett] ?an diamond4 ,9 ! r\gh ! diamond is less attractive 9 appe>ance ?an rock cry/al4 ,g4 ,f4 ,h]b]t-,smi? lik5s its appe>ance to t ( soda cry/als4 ,ano!r au?or lik5s x to gum arabic4 ,! surface ( ! r\gh diamond is usually ridg$ by ! ov]lapp+ ( m9ute lay]s or /rata ( ! mat]ial s t "o _c look into ! cle> int]ior any m ?an "o c look into a bank1 ?r\gh ! prism-glass w9d[s t are s mu* us$ to diffuse ! light t ent]s by means ( !m4 ,be+ ?us ( a r\gh ext]ior ! uncut diamond %[s none ( ! snap & fire :i* are develop$ by prop] cutt+4 ,z ! diamond p]haps %[s m improvem5t on be+ cut ?an any o!r /one1 & z ! art ( cutt+ ! diamond is di/9ct f t ( cutt+ o!r preci\s /ones1 bo? 9 ! me?od ( cutt+ & 9 ! fact t ! work]s :o cut diamonds cut no o!r preci\s /ones1 x w be well to consid] diamond cutt+ sep>ately4 ,be=e discuss+ ! me?ods by :i* ! %ap+ & poli%+ are accompli%$ let u consid] briefly ! object t is 9 view 9 ?us alt]+ ! %ape & smoo?+ ! surface ( ! r\gh mat]ial4 ,,h[ ,,cutt+ ,,increases ,,brilliancy4 ,prim>ily ! object ( cutt+ a diamond is to make x m brilliant4 ,s true is ?is t ! usual =m to :i* diamonds are cut has come to be call$ ! brilliant4 ,! adjective has become a n\n4 ,! increas$ brilliancy is due ma9ly to two effects3 ,fir/1 greatly increas$ reflection ( light1 & second1 disp]sion ( light4 ,! reflection is p>tly ext]nal b pr9cipally int]nal4 ,tak+ up fir/ ! int]nal reflection :i* is responsible = mo/ ( ! :ite brilliancy ( ! cut /one we mu/ note t x is a fact t light t is pass+ ?r\gh any transp>5t mat]ial w1 ^u arriv+ at any poli%$ surface1 ei!r p5etrate & em]ge or else x w be reflect$ )9 ! mat]ial1 dep5d+ ^u ! angle at :i* ! light /rikes ! surface4 ,= ea* mat]ial !re is a def9ite angle outside ( :i* light t is pass+ z above describ$1 is totally reflect$ )9 ! mat]ial4 ,illu/ration3 ,,fig4 #i4 ,,ab repres5ts ! back surface ( a piece ( diamond4 ,,cd is a l9e p]p5dicul> to ,,ab4 ,angle ,,cde is ab\t #bd degrees4 ,dott$ l9e1 ,,fdh repres5ts ! c\rse tak5 by a ray ( light :i* is totally reflect$ at ,d 9 su* fa%ion t angle ,,fda equals angle ,,hdb4 ,any light proce$+ t[>ds ,,ab b betwe5 ,e & ,c1 w\ld fail to be totally reflect$4 ,mo/ ( x w\ld p5etrate ,,ab4 ,,total ,,reflection4 ,= diamond ?is critical angle1 z x is call$1 is v ne>ly #bd f a p]p5dicul> to ! surface4 ,if n[1 we %ape a diamond s t mo/ ( ! light t ent]s x f ! front falls ^u ! fir/ back surface t x meets1 at an angle great] ?an #bd to a p]p5dicul> to t surface1 ! light w be totally reflect$ )9 ! /one4 ,! angle at :i* x is reflect$ w be ! same z t at :i* x meets ! surface4 ,9 o!r words ! angles ( incid5ce & ( reflection are equal4 ,see ,fig4 #i = an illu/ration ( ?is po9t4 ,,!ory ,,( ,,! ,,brilliant4 ,9 ! usual brilliant mu* ( ! light t ent]s ?r\gh ! front surface is ?us totally reflect$ f ! fir/ re> facet t x meets & !n proce$s across ! /one to be aga9 totally reflect$ f ! opposite side ( ! brilliant4 ,?is "t ! light proce$s t[>d ! top ( ! /one4 ,see ,fig4 #aj--7;,f ,g4 ,f4 ,h]b]t-,smi?'s ,gem-,/ones74 ,! angles ( ! top ( a brilliant are purposely made s flat t ! up com+ light fails to be totally reflect$ aga9 & is all[$ to em]ge to dazzle ! behold]4 ,9 ! bett] made brilliants ! angle t ! back slope makes ) ! plane ( ! girdle is v ne>ly #da & ! top angle1 or angle ( ! front slope to ! plane ( ! girdle is ab\t #ce4 ,su* well made brilliants :5 held up to a bright light appe> almo/ black--t is1 !y fail to pass any ( ! light ?r\gh !m 7except ?r\gh ! t9y culet1 :i*1 be+ p>allel to ! table above1 passes light t comes /raight d[n to x74 ,illu/ration3 ,,fig4 #aj4--;,,c\rse ,,( ,,! ,,rays ,,( ,,light ,,pass+ ,,?r\gh ,a ,,brilliant4 ,9 o!r words1 in/ead ( all[+ ! light to p5etrate !m1 well-made brilliants almo/ totally reflect x back t[>d its s\rce1 t is1 t[>d ! front ( ! /one4 ,! well-cut diamond is a v brilliant object1 view$ f ! front4 ,we mu/ n[ consid] h[ ! fire or prismatic color play is produc$1 = x is ev5 m ^u ! display ( fire ?an ^u its pure :ite brilliancy t ! beauty ( a diamond dep5ds4 ,,cause ,,( ,,fire4 ,z we saw 9 ,lesson ,x4 7:i* x w\ld be well to re-read at ?is "t71 :ite light t *anges its c\rse f "o transp>5t m$ium to ano!r at any b a "r angle to ! surface involv$1 is n only refract$ 7z we saw 9 ,lesson ,,ii47 b is disp]s$1 t is1 light ( diff]5t colors is b5t by diff]+ am\nts & ?us we h a sep>ation ( ! v>i\s colors4 ,if ?is takes place z ! ray ( light leaves ! upp] surface ( a brilliant ! obs]v] ^u ^: eye ! light falls w see ei!r ! r$1 or ! yell[1 or ! blue1 z ! case may be1 r ?an ! :ite light :i* ent]$ ! /one4 ,if in/ead1 ! disp]sion takes place z ! light ent]s ! brilliant ! v>i\s color$ rays ?us produc$ w be totally reflect$ back to ! obs]v] 7slightly weak5$ by spread+1 z comp>$ to ! direct or unreflect$ spectra74 ,?us disp]sion produces ! fire 9 a brilliant4 ,o!r mat]ials ?an diamond behave simil>ly1 b usually to a mu* small] ext5t1 = few gem mat]ials h s high a refractive p[] or s great a disp]sive p[] z diamond4 ,hav+ consid]$ ! !ory ( ! brilliant we may n[ take up a /udy ( ! me?ods by :i* ! exce$+ly h>d r\gh diamond is %ap$ & poli%$4 ,,cleav+ ,,diamonds4 ,if ! r\gh mat]ial is ( poor %ape1 or if x has conspicu\s defects 9 x :i* prev5t its be+ made into a s+le /one1 x is cleav$ 7i4 e41 split along its gra974 ,h>d z x is1 diamond splits readily 9 c]ta9 def9ite directions 7p>allel to any ( ! triangul> faces ( ! octah$ral cry/al74 ,! cleav] has to "k ! gra9 ( r\gh diamonds f ! ext]nal appe>ance1 ev5 :5 ! cry/als1 z f\nd1 are complicat$ modifications ( ! simple cry/al =m4 ,he c ?us take advantage ( ! cleavage to spe$ily r$uce ! r\gh mat]ial 9 size & %ape to suit ! necessity ( ! case4 ,! cleav+ is accompli%$ by mak+ a nick or groove 9 ! surface ( ! r\gh mat]ial at ! prop] po9t 7! /one be+ held by a t5aci\s wax1 9 ! end ( a hold]1 plac$ upright 9 a firm support74 ,a ?9 /eel knife blade is !n ins]t$ 9 ! nick & a %>p light bl[ /ruck ^u ! back ( ! knife blade4 ,! diamond !n readily splits4 ,,cutt+ ,,diamonds4 ,! next /ep is to give ! r\gh mat]ial a %ape closely simil> to t ( ! f9i%$ brilliant b r\gh & )\t facets4 ,?is %ap+ or cutt+ z x is te*nically call$1 is done by plac+ ! r\gh /one 9 ! end ( a hold] by means ( a t\gh cem5t & !n rotat+ hold] & /one 9 a la!-l ma*9e4 ,ano!r r\gh diamond 7sometimes a piece ( bort1 unfit = cutt+1 & sometimes a piece ( mat]ial ( good quality :i* x is necess>y to r$uce 9 size or alt] 9 %ape7 is cem5t$ into ano!r hold] & held aga9/ ! surface ( ! rotat+ diamond4 ,! hold] is /eadi$ aga9/ a firm support4 ,x n[ becomes a case ( diamond cut diamond1 ea* /one we>+ away ! o!r & be+ worn away itself4 ,! cutt+ process is fairly rapid & x leaves ! /one 7:i* is rev]s$ to make ! opposite side7 r\nd 9 =m & ) a r\nd+ top & cone-%ap$ back4 ,/ones ( fancy %ape1 su* z squ>e1 or cu%ion %ape1 h to be =m$ 9 "p by h& rubb+ or brut+ z x is call$4 ,! facets mu/ n[ be poli%$ onto ! /one4 ,usually ! work]s :o cut d n cleave or poli%4 ,,poli%+ ,,diamonds4 ,! poli%] fixes ! cut /one firmly 9 a metallic hold] call$ a dop1 :i* is clev]ly design$ to hold ! /one ) mu* ( "o side ( x expos$4 ,! hold] is !n inv]t$ s t ! /one is b5ea? & a /\t copp] wire atta*$ to ! hold] is !n clamp$ firmly 9 a sort ( movable vise4 ,! latt] is !n plac$ on ! b5* 9 su* a position t ! diamond re/s ^u ! surface ( a rapidly revolv+ horizontal iron :eel or lap z x is call$4 ,! surface ( ! latt] is *>g$ ) diamond du/1 t is1 diamond du/ has be5 pu%$ into ! metal surface :i* ?us acts z a support to ! du/4 ,! latt] we>s away ! diamond1 produc+ a flat facet4 ,! lap is kept moi/5$ ) oil & f "t to "t fre% oil & diamond du/ are appli$4 ,a spe$ ( ab\t #b1jjj rotations p] m9ute is us$4 ,,facett+4 ,! mak+ ( ! facets is r sl[ "w1 especially :51 z is usually ! case 9 mak+ ! table ! "w has to be done aga9/ "o ( ! h>d po9ts ( ! cry/al4 ,great c>e has to be tak5 to place ! /one s t ! gra9 lies 9 a correct position1 = diamond _c be poli%$ aga9/ ! gra91 nor ev5 exactly ) x1 b only obliquely across x4 ,?is requirem5t1 z mu* z any?+1 has prev5t$ ! use ( ma*9es 9 poli%+ diamonds4 ,! table is usually fir/ poli%$ on1 !n ! f\r top slopes1 divid+ ! top surface into qu>t]s1 !n ea* ( ! f\r ridges ?us left1 is flatt5$1 mak+ eight facets & f9ally #cb facets1 exclusive ( ! table1 are made ^u ! top ( ! brilliant4 ,! /one is !n rev]s$ & #bd facets1 & ! culet1 poli%$ on ! back4 ,z ea* facet ne>s its prop] %ape ! /one is plac$ ^u a p>ticul>ly smoo? "p ( ! lap & a slight vibratory motion giv5 to ! hold] by ! h&4 ,?is smoo?s out any l9es or grooves t may h =m$ because ( inequalities ( surface ( ! lap4 ,:5 completely facett$ ! brilliant is f9i%$ & requires only to be clean$1 :5 x is ready = sale4 ,,lesson ,,xxiii ,,h[ ,,r\gh ,,preci\s ,,/ones ,,are ,,cut ,,& ,,:at ,,con/itutes ,,good ,,make--,conclud$ ,,slitt+ ,,& ,,cleav+4 ,! cutt+ & poli%+ ( preci\s /ones o!r ?an diamond is a trade entirely di/9ct f diamond cutt+4 ,! preci\s /one lapid>y cuts e species ( /one except diamond4 ,! me?ods us$ by diff]5t lapid>ies v>y some:at 9 _! details1 & !re are _m trade secrets :i* are m or less jeal\sly gu>d$ by _! possessors1 b 9 g5]al ! me?ods us$ to r$uce ! r\gh mat]ials to ! f9i%$ gems are z foll[s3 ,fir/1 ! r\gh mat]ial1 if ( too l>ge size1 or if v imp]fect1 is slitt$1 or1 if x possesses a pron\nc$ cleavage1 x may be cleav$1 9 ord] to r$uce ! size or to remove imp]fect p>ts4 ,slitt+ is accompli%$ by means ( a circul> disc ( ?9 metal :i* is hamm]$ s t x w be flat & rotate truly1 & is !n clamp$ betwe5 face plates1 mu* z an em]y :eel is held4 ,! smoo? edge ( ! circul> disc is !n *>g$ ) diamond du/ & oil1 ! diamond du/ be+ b$d$ into ! edge ( ! metal disc by ! pressure ( "s h>d1 f9e-gra9$ mat]ial1 su* z *alc$ony1 or roll$ into ! metal by ! use ( a rotat+ roll]4 ,once *>g$1 & kept freely suppli$ ) oil1 a slitt+ :eel w slice a consid]able numb] ( pieces ( any preci\s /one less h>d ?an diamond1 & w d s ) consid]able rapidity4 ,! :eel is1 ( c\rse1 rotat$ v rapidly = ?is purpose4 ,! cleav+ ( c]ta9 gem mat]ials1 su* z true topaz 7:i* splits p]fectly across ! prism1 p>allel to its base7 is easily accompli%$1 & x is done 9 mu* ! same mann] z ! cleav+ ( diamond4 ,! feldsp> gems1 su* z moon/one1 amazonite1 & labradorite1 also cleave v smoo?ly 9 c]ta9 directions4 ,spodum5e1 ( :i* ,kunzite is a v>iety1 cleaves almo/ too easily to be durable4 ,mo/ gem m9]als1 h[ev]1 lack su* p]fect cleavage & :5 x is desir$ to remove imp]fect p>ts1 or to r$uce l>ge pieces to small] sizes1 ^! mat]ials are slitt$ z above describ$4 ,,rubb+ ,,d[n4 ,! mat]ial be+ ( ne>ly ! dim5sions ( ! f9i%$ piece1 ! next /ep is to rub x d[n1 z x is call$1 to approximately ! %ape & size desir$4 ,?is rubb+ d[n process 0 =m]ly done by means ( a s(t metal lap 7sometimes ( lead71 *>g$ ) co>se em]y p[d] & wat]4 ,c>borundum1 be+ h>d] & %>p] ?an em]y1 has replac$ x v l>gely4 ,"s ( ! s(t] mat]ials1 su*1 = example1 z turquoise1 are rubb$ d[n on a fa/ fly+ c>borundum :eel ( simil> type to ^? us$ 9 ma*9e %ops = gr9d+ /eel tools4 ,^! :eels rotate 9 a v]tical plane & are kept wet4 ,! laps be=e m5tion$ run horizontally4 ,! c>borundum :eels h ! gra9s ( c>borundum cem5t$ toge!r by means ( "s b9d+ mat]ial & ?is gradually crumbles1 expos+ fre%1 %>p cutt+ edges4 ,v>i\s sizes ( gra91 & v>i\s degrees ( h>dness ( ! b9d+ mat]ial1 z well z v>i\s spe$s1 are ne$$ to suit ! _m diff]5t mat]ials rubb$ d[n by ! lapid>y4 ,"s lapid>ies rub d[n ! h>d] & m valuable gems su* z ruby ^u diamond *>g$ laps ( brass or o!r metal4 ,,cabo*ons4 ,! rubb+ d[n process does n leave a facett$ surface1 b only a co>se r\ghly r\nd$ or flatt5$ surface4 ,if ! mat]ial is to be left 9 "s "o ( ! flat-back$1 r\nd$ top =ms kn[n z cabo*on cut1 ! surfaces ne$ only to be smoo!d 7by means ( v f9e abrasives su* z f9e em]y appli$ by means ( laps1 or ev5 by f9e em]y or c>borundum clo?71 & !y are !n ready = poli%+4 ,,facett$ ,,/ones4 ,if1 h[ev]1 ! /one is to be facett$ 9 ei!r ! brilliant =m1 some:at l ! diamond1 or /ep cut or o!rwise facett$1 x is cem5t$ /rongly onto a hold] 7mu* l ! wood5 "p ( a p5 hold]74 ,! upp] end ( ! hold] is re/$ 9 "o ( a s]ies ( holes 9 :at is call$ a g9peg re/+ 9 ! "w-b5* ne> a metal lap1 & ! /one is press$ ^u ! rapidly rotat+ surface ( ! lap1 :i* is *>g$ ) diamond du/ or c>borundum1 accord+ to ! h>dness ( ! mat]ial to be facett$4 ,a flat facet is ?us gr\nd ^u ! /one4 ,by rotat+ ! hold] a s]ies ( facets1 all 9 ! same set1 is produc$4 ,! hold] is !n *ang$ to a new position on ! g9peg & ano!r set ( facets laid ^u ! /one4 ,?us z _m z f\r or five ti]s or sets ( facets may be appli$ to "o side1 say ! top ( ! /one4 ,! latt] is !n remov$ f ! hold] & cem5t$ to x aga91 ?is "t ) ! bottom expos$1 & sev]al sets ( facets appli$4 ,! /one is n[ cut b n poli%$4 ,! facets are flat1 b h a r\gh gr\nd-glass l surface4 ,! poli%+ is usually done by work]s :o d n cut /ones1 b :o d no?+ b poli% !m4 ,9 small %ops1 h[ev]1 ! same lapid>y p]=ms all ! p>ts ( ! "w4 ,,poli%+4 ,! poli%+ ( /ones1 :e!r cabo*on or facett$1 is accompli%$ by ! use ( v f9ely p[d]$ abrasives su* z corundum p[d]1 tripoli1 pumice1 putty p[d]1 etc4 ,ea* gem mat]ial requires special treatm5t to obta9 ! be/ results4 ,x is "h t mo/ ( ! trade secrets apply4 ,! tr\bles ( ! lapid>y 9 gett+ ! ke5 poli% t is s mu* admir$ on f9e gems are _m4 ,9 g5]al1 ! poli%+ p[d] %\ld n be q z h>d z ! mat]ial to be poli%$1 else x may gr9d r ?an poli%4 ,! mat]ial %\ld be us$ ) wat] or oil to give x a creamy consi/5cy4 ,x %\ld be back$ by laps ( diff]5t mat]ials = diff]5t purposes4 ,?us1 :5 back$ by a fairly h>d metal ev5 tripoli1 al?\gh mu* s(t]1 w poli% sapphire4 ,on a lap ( wood1 tripoli w\ld fail to poli% h>d mat]ials1 b w\ld poli% ame?y/ or o!r qu>tz gem4 ,a *ange ( spe$ ( ! lap1 too1 *anges ! effect ( ! poli%+ mat]ial4 ,i h se5 a lapid>y1 :o 0 hav+ no success at poli%+ an em]ald1 get v good results by us+ a /ick z a brake & sl[+ d[n 8 lap4 ,! poli%+ mat]ial mu/ be ( v uni=m size1 pref]ably wat] float$ or oil float$1 to give good results4 ,! lap mu/ be kept flat & true & ! /one mu/ be prop]ly held1 or ! flatness ( ! facets1 ^u :i* brilliancy dep5ds 9 "p1 w be de/roy$ dur+ ! poli%+4 ,! s(t] mat]ials1 su* z opal1 require treatm5t m l t accord$ cut glass1 & s(t abrasive p[d]s1 su* z pumice1 suffice to poli% !m4 ,probably h>dly two lapid>ies w\ld "w exactly alike 9 _! treatm5t ( preci\s /ones1 & ea* gu>ds 8 secrets1 yet all use approximately simil> g5]al me?ods4 ,"s h devis$ me*anical hold]s :i* p]mit ! repeat$ cutt+ ( /ones to exactly ! same angles1 & t1 too1 ) an accurate k ( ! angles us$4 ,^! angles c be def9itely alt]$ = diff]5t mat]ials1 accord+ to _! refractive indices4 ,o!r lapid>ies produce v f9e results by purely h& me?ods4 ,^! details h be5 gone into to give an idea ( ! me?ods ( ! lapid>y & ( ! _m v>iations 9 me?od4 ,9 g5]al1 h[ev]1 ! slitt+ or cleav+1 ! rubb+ d[n to %ape1 ! smoo?+ out ( all scrat*es & ! facett+ & poli%+ are done some:at simil>ly by all lapid>ies4 ,hav+ n[ _h a glimpse ( ! me?ods ( ! lapid>ies1 let u briefly consid] :at con/itutes good make 9 /ones o!r ?an diamond4 ,,good ,,make ,,9 ,,color$ ,,/ones4 ,brilliants1 cut f mat]ials hav+ small] refractive indices ?an diamond1 7& ?is gr\p includes ne>ly all /ones o!r ?an diamonds7 %\ld h /eep] back angles & high] tops ?an ! be/ diamond brilliants h4 ,a #ce-;degree top angle 7! angle betwe5 ! slope ( ! top & ! plane ( ! girdle is call$ ! top angle7 & a #da-;degree back angle be+ ab\t ideal = diamond1 o!r gem mat]ials %\ld h m ne>ly a #ci-;degree top angle & a #dd-;degree back angle to give ! greate/ possible brilliancy4 ,h[ev]1 9 ! case ( color$ gems su* z ruby1 sapphire1 etc41 :]e ! value dep5ds ev5 m l>gely ^u ! color ?an ^u ! brilliancy1 x is frequ5tly necess>y to cut ! brilliant ?ick] or ?9n] ?an ^! proportions 9 ord] to deep5 or to ?9 ! color4 ,9 g5]al1 ! ?ick] a /one ( a giv5 spread ! deep] ! color w be4 ,! color may also be deep5$ by giv+ to ! /one a r\nd$ cont\r1 bo? above & bel[ ! girdle1 & facett+ x 9 /eps in/ead ( 9 ! brilliant =m4 ,increas+ ! numb] ( /eps also s]ves to slightly deep5 ! color1 z a l>g] numb] ( reflections is ?us obta9$ )9 ! mat]ial1 ! light ?us has to travel a great] di/ance ?r\gh ! color$ mass1 & m ( ! light1 ( color o!r ?an t ( ! /one1 is absorb$4 ,,improv+ ,,color ,,by ,,prop] ,,cutt+4 ,9 addition to ! color improvem5t t c be br\ght ab\t by *ang+ ! %ape ( ! cut /one !re are a numb] ( gem mat]ials ^: color v>ies v greatly 9 diff]5t directions1 & ?is fact calls = skillful use 9 ord] to obta9 ! be/ possible results4 ,?us mo/ t\rmal9es ( deep color mu/ be cut ) ! top or table1 ( ! f9i%$ /one1 on ! side ( ! prismatic cry/al r ?an at "r angles to ! axis ( ! prism4 ,if cut ! latt] way !y w\ld be mu* too d5se 9 color4 ,on ! o!r h&1 mo/ blue sapphires %\ld be cut across ! prism axis r ?an ! way t t\rmal9es %\ld be cut4 ,to cut a sapphire ) its table on ! side ( ! prism w\ld be likely to cause x to h a gre5i% ca/ because ( ! admixture ( ! unpleas+ ord9>y ray ( yell[i% t9t ) ! blue ( ! /one z se5 up & d[n ! prism4 ,"s ,au/ralian sapphires are ( a pron\nc$ gre5 :5 view$ across ! axis ( ! cry/al4 ,rubies if cut1 z 0 recomm5d$ = sapphires1 give a v pure & v deep r$ color1 b lack some:at 9 ! display ( di*roism giv5 by rubies t are cut ) ! table on ! side ( ! cry/al & p>allel to its axis4 ,lapid>ies ne$ to "k & to make use ( su* optical relations z ^! & jewel]s might well in=m !mselves 9 su* matt]s1 especially if !y h1 or hope to acquire1 trade 9 v f9e color$ /ones4 ,,effect ,,( ,,%ape ,,on ,,brilliancy4 ,9 actual practice x is common to f9d color$ /ones poorly cut = brilliancy1 especially c5tral brilliancy1 & t1 too1 )\t ! excuse ( sacrifice ( brilliancy 9 ord] to improve color4 ,! fault is usually due to too great a desire to save size & weight4 ,frequ5tly a /one w\ld h great] value if prop]ly cut1 ev5 at ! exp5se ( "s size & weight4 ,:5 /ones are cut too %all[1 z is frequ5tly ! case1 !y are sure to leak light 9 ! c5t] & !y are ?us weak & less brilliant !re ?an !y w\ld be if made small] 9 diamet] & ) /eep] back slopes approximat+ #dd degrees4 ,r\nd /ones1 if _! angles are correct1 are m brilliant ?an /ones ( o!r cont\r su* z squ>e or cu%ion %ape1 or navette or he>t %ape4 ,x c readily be se5 t su* odd-%ap$ /ones c h>dly h ! same top & back angles at e "p ( _! circumf]5ce4 ,if ! angle f a corn] ( a squ>e /one is correct !n ! angle f ! middle ( "o side is obvi\sly a little diff]5t4 ,small diff]5ces ( angle make consid]able diff]5ces 9 ! brilliancy ( cut /ones4 ,! prevail+ t5d5cy to cut ne>ly all diamonds r\nd dep5ds l>gely ^u ! above facts4 ,9 ! case ( color$ /ones1 h[ev]1 ! add$ attractiv5ess :i* comes ) odd or diff]5t cont\r m ?an makes up = ! slight loss ( brilliancy t may att5d ^u ! %ape select$4 ,su* %apes z l5d !mselves to special designs 9 m\nt+s also ju/ify any little loss 9 brilliancy t accompanies ! *ange 9 %ape1 provid$ ! proportions reta9$ give a consid]able am\nt ( total reflection )9 ! /one & ?us light up mo/ ( ! /one z se5 f ! front4 ,! te/ ( ! make ( a color /one is its appe>ance4 ,if x lights up well ov] mo/ ( its surface & if ! color is "r1 "o %\ld n criticize ! make z "o w\ld be ju/ifi$ 9 do+ 9 ! case ( a diamond4 ,if1 h[ev]1 ! effect is less attractive x w\ld _m times be advisable to measure ! angles ( ! /one1 or its ?ickness & spread z comp>$ ) simil> measurem5ts on a /one ( f9e appe>ance4 ,frequ5tly "o w ?us f9d ! reason = ! failure ( ! /one to p]=m z x might1 & recutt+ %\ld be resort$ to 9 su* cases 9 ord] to get a small] b m beautiful & h5ce m valuable /one4 ,,lesson ,,xxiv ,,=ms ,,giv5 ,,to ,,preci\s ,,/ones ,:ile preci\s /ones are cut to _m diff]5t =ms1 !re are1 nev]!less1 b a few g5]al types ( cutt+4 ,^! may be classifi$ z foll[s3 ,fir/1 ! cabo*on 7,fig4 #aa7 type ( cutt+2 second1 ! old rose 7,fig4 #ab7 type ( cutt+2 ?ird1 ! brilliant 7,fig4 #ac72 f\r?1 ! /ep cutt+ 7,fig4 #ad74 ,,cabo*ons4 ,( ^! ! fir/1 or cabo*on cutt+1 is probably ! mo/ anci5t4 ,! t]m comes f a ,fr5* ^w signify+ a bald pate 7cabo*e1 f ,lat9 cabo1 a head74 ,! usual r\nd cabo*on cut closely resembles ! top ( a head 9 %ape4 ,cabo*on cut /ones usually h a flat base1 b sometimes a slightly convex base is us$1 especially 9 opals & 9 moon/ones1 & "s /ones ( v d5se color are cut ) a concave base to ?9 !m & ?us to r$uce _! color4 ,! cont\r ( ! base may be r\nd1 or oval1 or squ>e1 or cu%ion %ape1 or he>t %ape or ( any regul> =m4 ,! top is always smoo? & r\nd+ & unfacett$4 ,! relation ( ! height or ?ickness to ! l5g? or wid? may be v>i$ to suit ! size & %ape ( ! r\gh piece or to suit "o's ideas ( symmetry1 provid$ ! mat]ial be an opaque "o1 su* z turquoise or lapis lazuli4 ,if1 h[ev]1 ! mat]ial is transp>5t ! be/ results 9 ! way ( ! return ( light to ! front1 & h5ce 9 ! display ( ! color ( ! mat]ial1 are _h if ! ?ickness is ab\t "o half ! spread4 ,illu/ration3 ,,fig4 #aa4--;,,cabo*on ,,cutt+4 ,?is relation dep5ds ^u ! refractive index ( ! mat]ial1 b z mo/ color /ones are ( some:at simil> refractive indices1 ! above proportions are suffici5tly accurate = all4 ,! object 9 view is ! secur+ ( total reflection ( z mu* light z possible f ! flat poli%$ back ( ! /one4 ,cabo*on /ones are sometimes set ov] foil or on poli%$ gold to increase ! reflection ( light4 ,! pa? ( a ray ( light ?r\gh a cabo*on cut /one is closely simil> to t ?r\gh a rose cut diamond see cut 7c7 ( ,fig4 #ab = ! latt]4 ,l ! rose cut1 ! cabo*on cut does n give mu* brilliancy z comp>$ to ! brilliant cut4 ,cabo*on cut /ones1 h[ev]1 h a quiet beauty ( color :i* comm5ds !m to p ( quiet ta/e1 & ev5 f9e rubies1 sapphires1 & em]alds are increas+ly cut cabo*on to satisfy ! gr[+ dem& = f9e ta/e 9 jewels4 ,! ,ea/ ,indian has all along pref]r$ ! cabo*on cut = color /ones1 b possibly 8 motives h n be5 unmix$1 z ! cabo*on cut saves a great] proportion ( ! weight ( ! r\gh /one ?an ! m mod]n types ( cutt+4 ,g>nets1 m ?an o!r /ones1 h be5 us$ 9 ! cabo*on cut1 & :5 9 t =m are usually kn[n z c>buncles 7f c>bunculus1 a gl[+ coal74 ,any o!r fi]y r$ /one might equally well be /yl$ a c>buncle1 especially if cabo*on cut4 ,illu/ration3 ,,fig4 #ab4--,,rose ,,cutt+4 ,sci5tific rubies look v well 9 ! cabo*on cut4 ,fig4 #aa %[s 9 7a7 & 7b7 ! front & top ( ! usual r\nd cabo*on4 ,cut 7c7 ( ! same figure gives ! front elevation ( a cabo*on :i* w light up bett] ?an ! usual r\nd-topp$ design4 ,9 ! r\nd-topp$ type ! c5tral "p ( ! top is s ne>ly p>allel to ! back t light c pass "r ?r\gh z ?r\gh a w9d[ pane4 ,if ! slop+ sides are br\ght up to a blunt po9t1 z 9 cut 7c7 !re is v mu* less loss ( light & great] beauty results4 ,! ,ea/ ,indian cabo*ons are frequ5tly cut 9 a fa%ion resembl+ t sugge/$4 ,illu/ration3 ,,fig4 #ac4--;,,brilliant ,,cutt+4 ,,rose ,,cut ,,/ones4 ,x 0 natural t ! e>lie/ cut /ones %\ld h ! simple r\nd$ l9es ( ! cabo*on cutt+1 = ! fir/ ?+ t w\ld occur to ! primitive work] :o aspir$ to improve ^u nature's product1 w\ld be ! rubb+ d[n ( %>p edges & ! poli%+ ( ! :ole surface ( ! /one4 ,p]haps ! next improvem5t 0 ! poli%+ ( flat facets ^u ! r\nd$ top ( a cabo*on /one4 ,?is process gives u ! anci5t type ( cutt+ kn[n z ! rose cut4 ,! draw+s 7a7 & 7b7 ( ,fig4 #ab %[ ! front elevation & ! top & 7c7 %[s ! pa? ( a ray ( light ?r\gh a rose4 ,x w be not$ t ! g5]al %ape resembles t ( a r\nd cabo*on1 b tw5ty-f\r triangul> facets h be5 =m$ ^u ! top4 ,! well-proportion$ rose has a ?ickness ab\t "o half z great z its diamet]4 ,diamonds 7 =m]ly cut *iefly 9 ! rose =m1 especially 9 ! days ( ! ,ea/ ,indian m9es1 & ev5 9 ! e>ly "p ( ! n9ete5? c5tury _m p pref]r$ f9ely made roses to ! ?ick1 clumsy brilliants ( t day4 ,to-day only v small pieces ( diamond are cut to roses4 ,z ! mat]ial s us$ frequ5tly results f ! cleav+ ( l>g] diamonds1 ! public has come to "k ^! t9y roses z *ips4 ,! be/ roses h tw5ty-f\r regul> facets b small ones frequ5tly receive only twelve1 & ^? are seldom regul> 9 %ape & 9 arrangem5t4 ,su* roses s]ve well en\gh = encru/+ wat* cases & = simil> "w1 z ! flat base ( ! /one c be set 9 ?9 metal )\t difficulty4 ,ab\t ! only gem o!r ?an diamond t is n[ cut to ! rose =m is g>net4 ,l>ge numb]s ( small ,bohemian g>nets are cut to crude rose =m = use 9 clu/] "w4 ,illu/ration3 ,,fig4 #ad4--,,/ep ,,cutt+4 ,,! ,,brilliant ,,cut1 z its "n implies1 gives ! mo/ complete return ( light ( any ( ! =ms ( cutt+4 ,! !ory ( ! brilliant has already be5 discuss$ 7,lesson ,,xxii4 9 connection ) ! cutt+ ( diamond74 ,! %ape ( ! brilliant is too well kn[n to require mu* description4 ,mo/ brilliants to-day are cut practically r\nd & ! =m is t ( two truncat$ cones plac$ base to base4 ,! upp] cone is truncat$ m ?an ! l[]1 ?us =m+ ! l>ge1 flat top facet kn[n z ! table ( ! /one ,a1 ,fig4 #ac1 cut 7a74 ,! truncat+ ( ! l[] cone =ms ! t9y facet kn[n z ! culet1 :i* lies opposite to ! table & is p>allel to ! latt] see ,b1 ,fig4 #ac1 cut 7a74 ,! edge ( meet+ ( ! two cones is ! girdle ( ! brilliant ,,cd 9 cut 7a71 ,fig4 #ac4 ,! slop+ surface ( ! upp] cone is facett$ ) ?irty-two facets 9 ! full cut brilliant1 :ile ! l[] cone receives tw5ty-f\r4 ,small /ones sometimes receive few] facets1 to less5 ! co/ & difficulty ( cutt+1 b by pay+ suffici5t = !m full cut brilliants z small z "o hundr$ to ! c>at may be _h4 ,cut 7b7 ( ,fig4 #ac %[s ! prop] arrangem5t ( ! top facets & cut 7c7 t ( ! bottom facets4 ,:5 cutt+ color$ /ones 9 ! brilliant cut1 especially if ! mat]ial is v co/ly & its color 9 ne$ ( be+ d>k5$ or light5$1 ! lapid>y frequ5tly takes lib]ties ) ! regul> arrangem5t & proportions depict$ 9 ! cuts4 ,,/ep ,,cutt+4 ,! only rema9+ type ( cutt+ t is 9 v g5]al use is ! /ep cut 7sometimes kn[n z trap cut74 ,fig4 #ad1 7a71 7b71 & 7c71 %[s ! front elevation1 ! top & ! back ( a squ>e antique /ep cut /one4 ,! cont\r may be r\nd or completely squ>e or oblong or ( "s o!r %ape1 j z a brilliant may h any ( ^! cont\rs4 ,! di/9ctive feature ( ! /ep cutt+ is ! sev]al s]ies ( p>allel-edg$ quadrangul> facets above & bel[ ! girdle & ! g5]ally r\nd+ "* ( its cross section4 ,?is plump1 r\nd+ "* p]mits ! sav+ ( weight ( ! r\gh mat]ial1 & by mass+ ! color gives usually a great] dep? ( color ?an a brilliant ( ! same spread w\ld h if cut f simil> mat]ial4 ,:ile probably nev] q z snappy & brilliant z ! regul> brilliant cut1 a well-proportion$ /ep cut /one c be v brilliant4 ,_m f9e diamonds h rec5tly be5 cut 9 /eps = use 9 exclusive jewelry4 ,,! ,,mix$ ,,cut4 ,! ruby & ! em]ald are nev] bett] 9 color ?an :5 9 ! full /ep cut1 al?\gh rubies are frequ5tly cut 9 :at is kn[n z ! mix$ cut1 consi/+ ( a brilliant cut top & a /ep cut back4 ,sapphires & _m o!r color$ /ones are commonly cut 9 ! mix$ cut4 ,rec5tly x has become common to poli% ! tops ( color$ /ones ) a smoo? unfacett$1 slightly convex surface1 ! back be+ facett$ 9 ei!r ! brilliant or ! /ep arrangem5t4 ,su* /ones are said to h a buff$ top4 ,!y are less exp5sive to cut ?an fully facett$ /ones & d n h ! snappy brilliancy ( ! latt]4 ,!y d1 h[ev]1 %[ (f ! intr9sic color ( ! mat]ial v well4 ,,lesson ,,xxv ,,imitations ,,( ,,preci\s ,,/ones ,,pa/e ,,gems4 ,l>ge volumes h be5 writt5 on pa/e jewels1 especially on antique pa/es4 ,contr>y to a prevail+ belief1 ! pa/e gem is n a rec5t inv5tion4 ,p frequ5tly say :5 told t _! gems are false1 ,b x is a v old piece1 x mu/ be g5u9e4 ,! great age ( a jewel %\ld r lead to suspicion t x 0 n g5u9e ?an give confid5ce t a true gem 0 assur$4 ,! ,egyptians & ,romans 7 skillful mak]s ( glass ( ! sort us$ 9 imitat+ gems & "s ( ! old pa/es 7 v h>d or else h become s ) age4 ,glass ( "o v>iety or ano!r makes ! mo/ conv9c+ sort ( imitation preci\s /ones4 ,! t]m pa/e z appli$ to glass imitations is said to come f ! ,italian pa/a mean+ d\gh1 & x sugge/s ! s(tness ( ! mat]ial4 ,mo/ pa/es are ma9ly lead glass4 ,z we saw 9 ,lesson ,,xviii41 on ! *emical composition ( ! gems1 _m ( !m are silicates ( metals4 ,n[ glasses are also silicates ( v>i\s metals1 b unlike gem m9]als ! glasses are n cry/all9e b r amorph\s1 t is1 )\t def9ite geometric =m or def9ite int]nal arrangem5t4 ,! optical prop]ties ( ! v>i\s glasses v>y *iefly ) _! d5sities1 & ! d5s] ! mat]ial ! high] ! refractive index & ! great] ! disp]sion4 ,?us to get ! be/ results 9 imitation /ones !y %\ld be made ( v heavy glass4 ,! d5se fl9t glass 7*iefly a silicate ( potassium & lead7 :i* is us$ = cut glass w>e illu/rates admirably ! optical prop]ties ( ! heavy glasses4 ,by us+ ev5 m lead a /ill d5s] glass may be _h1 ) ev5 a great] brilliancy4 ,un=tunately ! addition ( lead or o!r heavy metals 7su* z ?allium7 makes ! product v s(t & also v subject to attack by gases su* z are always pres5t 9 ! atmosph]e ( cities4 ,?is s(tness causes ! /ones to scrat* readily s t :5 worn !y soon lose _! poli% & ) ! loss ( poli% !y lose _! beauty4 ,! attack ( ! gases be=e m5tion$ d>k5s ! surfaces ( ! imitation & fur!r dulls x4 ,:5 fre% & new a well cut piece ( colorless pa/e has a snap & fire t approa*es t ( diamond4 ,! surface lu/] is n adamant9e1 h[ev]1 & ! edges ( ! facets _c be poli%$ s %>ply z ^? on a diamond4 ,moreov] ! refractive index1 :ile high1 is nev] s high z 9 a diamond & h5ce ! brilliant _c be s %ap$ z to secure ! am\nt ( total reflection giv5 by a well-made diamond4 ,h5ce1 ! pa/e brilliant1 :ile q satisfy+ z se5 f squ>ely 9 front1 is weak & d>k 9 ! c5t] z se5 :5 tilt$ to "o side4 ,by ^! diff]5ces ! tra9$ eye c detect pa/e imitations ( diamond at a glance )\t rec\rse to te/s ( specific gravity1 h>dness1 etc4 ,pa/es1 be+ amorph\s1 are s+ly refract+1 z is diamond4 ,?is fact helps ! appe>ance ( ! pa/e brilliant1 = light does n divide )9 x to become weak5$ 9 p[]4 ,?is s+l5ess ( refraction1 h[ev]1 betrays ! pa/e imitation :5 x is color$ to resemble ruby1 sapphire or em]ald1 all ( :i* are d\bly refract+4 ,! color is imp>t$ to pa/es by ! addition1 dur+ _! manufacture1 ( v>i\s metallic oxides 9 small proportions4 ,?us cobalt gives a blue color1 copp] or *romium gre51 copp] or gold give r$ 7"u prop] treatm5t7 & manganese gives purple4 ,by exp]im5t ! mak]s ( pa/es h become v skillful 9 imitat+ ! color ( almo/ any preci\s /one4 ,f9e pa/e em]alds may look bett] ?an inf]ior g5u9e em]alds4 ,z pa/es are s+ly refract+ & h5ce lack di*roism1 ! pleas+ v>iety ( color ( ! true ruby _c be _h 9 a pa/e imitation1 b ! public is n critical en\gh to notice ?is lack4 ,! exp]t w\ld1 h[ev]1 note x & c\ld detect ! imitation by t diff]5ce z well z by ! lack ( d\ble refraction4 ,! use ( direct sunlight & a :ite c>d z already expla9$ 9 ! lesson on d\ble refraction 7,lesson ,,iii47 w s]ve to expose ! s+l5ess ( refraction ( pa/e imitations4 ,sp9els & g>nets are ab\t ! only true gems 7except diamond7 t are s+le refract+4 ,any o!r color /one %\ld %[ d\ble refraction :5 te/$ by ! sunlight-c>d me?od4 ,! file te/ w also expose any pa/e imitation z all ! v brilliant pa/es are fairly s(t4 ,,d\blets4 ,to give bett] we>+ quality to pa/e imitations ! d\blet 0 devis$4 ,?is "n is us$ because ! product is 9 two p>ts1 a l[] or back portion ( pa/e & an upp] or top portion ( "s *eap b h>d g5u9e /one4 ,g>net is probably us$ = ?is purpose to a great] ext5t ?an any o!r mat]ial1 al?\gh qu>tz or colorless topaz w d v well4 ,! usual arrangem5t ( ! p>ts c be se5 9 ,fig4 #ae1 ! g>net cov]+ only a "p ( ! upp] surface1 namely ! table "p & a small portion ( ! slop+ surface ( ! top4 ,9 high class d\blets ! h>d m9]al cov]s ! pa/e to ! girdle4 7,see ,fig4 #af47 ,! color ( ! g>net does n int]f]e s]i\sly ) t ( ! pa/e4 ,illu/ration3 ,,fig4 #ae4 ,,"o ,,=m ,,( ,,*eap ,,d\blet4 ,if a diamond d\blet is desir$ ! slice ( g>net is made ne>ly z ?9 z pap] & x cov]s only ! table ( ! brilliant4 ,x is ?us practically colorless4 ,a ?9 slice ( r$ g>net ov] a gre5 backgr\nd is n noticeable1 z all ! r$ is absorb$ 9 pass+ ?r\gh ! gre5 mat]ial b5ea?4 ,) a blue base1 ! r$ upp] lay] may give a v slight purple effect4 ,) yell[ a slight orange t9t results & ( c\rse ) a r$ back no p]ceptible diff]5ce w\ld result4 ,illu/ration3 ,,fig4 #af4 ,,ano!r ,,=m ,,( ,,d\blet4 ,! two mat]ials are cem5t$ toge!r1 by means ( a transp>5t wat]pro( cem5t4 ,! triplet has already be5 describ$ 9 ,lesson ,,xii4 ,x is ev5 bett] ?an ! d\blet & m difficult to detect4 ,bo? ! file te/ & ! sunlight-c>d te/ s]ve to detect d\blets1 z well z pa/e imitations1 except t 9 ! file te/ ) ! fully protect$ d\blet ! back ( ! /one mu/ be te/$ ) ! file1 z ! girdle & top are ( h>d mat]ial4 ,9 ! sunlight-c>d te/ ( a d\blet 7! refraction ( g>net be+ s+le l t ( glass71 s+le images ( ! facets w be _h on ! c>d :5 ! sunlight is reflect$ onto x4 ,a reflection ( ! l[] or inn] surface ( ! g>net top c be se5 also & ?is s]ves to /ill fur!r id5tify a d\blet or a triplet4 ,! appe>ance ( ?is reflection is mu* l t receiv$ on ! c>d f ! top ( ! table4 ,x is l>g] ?an ! reflections ( ! small] facets & is b little color$4 ,,te/s ,,= ,,d\blets4 ,a tra9$ eye c also detect a d\blet or a triplet by not+ ! diff]5ce 9 ! "* ( ! surface lu/] ( ! g>net "p & ( ! glass "p4 ,g>net takes a ke5] & m res9\s lu/] ?an glass4 ,by tipp+ ! d\blet s t light is reflect$ to ! eye f ! slop+ top surface1 "o c see at once :]e ! g>net leaves (f & ! glass beg9s4 ,ev5 ?r\gh a %[ w9d[ "o c tell a d\blet 9 ?is way al?\gh "h x is necess>y to move oneself1 in/ead ( ! /one1 until a prop] position is obta9$ to get a reflection f ! top slope ( ! d\blet4 ,if ! g>net cov]s ! :ole top ( ! imitation !n x is n possible to get s direct a comp>ison1 b ev5 "h "o c look fir/ at ! top surface & !n at ! back & ?us comp>e ! lu/]4 ,x is also well to closely exam9e ) a l5s ! region ( ! girdle1 to see if any evid5ce ( ! jo9+ ( two mat]ials c be se54 ,frequ5tly ! lapid>y bevels ! edge s z to br+ ! l9e ( junction betwe5 real & false mat]ial at ! %>p edge ( ! bevel4 ,boil+ a d\blet 9 alcohol or *lor(orm w frequ5tly dissolve ! cem5t & sep>ate ! p>ts4 ,! di*roscope also s]ves to detect ! false "* ( d\blets & pa/e imitations1 z nei!r %[s di*roism4 ,z rubies1 em]alds1 sapphires1 & 9 fact mo/ color$ /ones ( value1 %[ di/9ct di*roism1 ?is te/ is a sure "o aga9/ ^! imitations4 ,triplets & d\blets too may be expos$ by dipp+ !m sidewise into oil1 ?us remov+ ! prismatic refraction almo/ completely1 z ! oil has ab\t ! same refractive index z ! /one4 ,"o c !n look directly ?r\gh glass & g>net1 or o!r topp+ mat]ial1 sep>ately1 & ea* mat]ial !n %[s its prop] color4 ,?us zones ( color appe> 9 a d\blet or triplet :5 "u ! oil4 ,a real gem w\ld appe> almo/ uni=m 9 color "u ^! conditions4 ,r\nd gas bubbles c frequ5tly be f\nd 9 pa/e1 & h5ce 9 ! pa/e "p ( a d\blet4 ,also1 ! natural flaws ( ! real /one are nev] f\nd 9 pa/e1 b may be pres5t 9 ! real /one "p ( a d\blet or a triplet4 ,"s imitation em]alds on ! m>ket1 h[ev]1 h be5 made 9 a way to c\nt]feit ! flaws & faults g5]ally f\nd 9 ?is /one4 ,,alt]$ ,,/ones4 ,9 addition to ! out & out imitations made ( pa/e1 & ! d\blets1 !re are num]\s imitations curr5t 9 ! trade t are made by /a9+ or by o!rwise alt]+ ! color ( "s g5u9e b inexp5sive gem mat]ial4 ,= example1 l>ge quantities ( some:at por\s *alc$ony f ,brazil are /a9$ & sold 9 imitation ( natural agate or s>d or o!r /ones4 ,9 _m cases ! /a9+ is sup]ficial1 s t ! /one has to be %ap$ be=e x is /a9$1 !n /a9$ & poli%$4 ,l>ge quantities ( slightly crackl$ qu>tz are /a9$ to resemble lapis lazuli1 & sold1 usually ) ! title ,swiss ,lapis4 ,a file te/ w reveal ! "* ( ?is imitation1 z x is h>d] ?an a file1 :ile true lapis is s(t]4 ,! color too is nev] ( s f9e a blue z t ( f9e lapis4 ,x has a ,prussian blue effect4 ,turquoises ( inf]ior color are also sometimes /a9$ to improve !m4 ,a bett] product is made artificially4 ,opals are sometimes impregnat$ ) organic matt]1 :i* is !n *>r$1 p]haps ) sulphuric acid1 ?us giv+ !m some:at ! appe>ance ( black opal4 ,opals are also imitat$ by add+ oxide ( t9 to glass1 ?us imp>t+ a slight milk9ess to x4 ,! imitation is !n %ap$ f ?is glass by mold+1 & ! back ( ! cabo*on is giv5 an irregul> surface1 :i* may be set ov] t9sel to give ! effect ( fire4 ,pale /ones are frequ5tly m\nt$ ov] foil1 or 9 enamel$ or /a9$ sett+s & ?us _! color is seem+ly improv$4 ,diamonds ( poor color are occasionally pa9t$2 (t5 ! back ( ! brilliant is treat$ ) a violet dye/uff1 :i* ev5 9 s small an am\nt t x is difficult to detect1 w neutralize ! yell[ ( ! /one & make x appe> to be ( a f9e blue-:ite color4 ,! pa9t+ is1 ( c\rse1 n p]man5t1 s t su* treatm5t ( a diamond ) a view to sell+ x is fraudul5t4 ,! pa9t$ /one may be detect$ by wa%+ x ) alcohol1 :5 ! dye w be remov$ & ! (f-color w become app>5t4 ,if ! /one is unset "o c see ) a l5s a wav]y metallic appe>ance on ! surfaces t h be5 pa9t$4 ,?is effect is due to ! action ( ! v ?9 film ( dye ^u ! light t falls ^u x4 ,besides ! /a9+ ( g5u9e mat]ials1 !y are sometimes alt]$ 9 color by heat treatm5t1 & ?is topic w be discuss$ 9 ! next lesson4 ,,lesson ,,xxvi ,,alt]ation ,,( ,,! ,,color ,,( ,,preci\s ,,/ones ,_m gem m9]als *ange color :5 m or less /rongly heat$4 ,extreme heat :it5s _m color$ mat]ials completely4 ,,p9k$ ,,topaz4 ,john ,rusk9 advises u to seek out & ca/ aside all mann] ( false or dy$ or alt]$ /ones b1 9 spite ( 8 advice1 p]haps ! mo/ ju/ifiable use ( heat treatm5t is t :i* alt]s ! color ( true topaz f a w9e-yell[ to a f9e p9k4 ,x w\ld appe> t ! w9e-yell[ is a composite color compos$ ( p9k & yell[ & t ! p9k con/itu5t is less easily *ang$ by heat ?an is ! yell[ "o4 ,if too high a temp]ature is us$ bo? colors disappe> & :ite topaz results4 ,z ! latt] is abundant 9 nature & ( little value1 su* a result is v undesirable4 ,p9k topaz1 h[ev]1 is v r>e1 & until rec5tly1 :5 p9k t\rmal9e f ,cali=nia & ,madagasc>1 & p9k b]yl 7morganite7 f ,madagasc>1 became available 9 quantity1 ! p9k$ topazes _h b few compet+ gems1 & ?us comm&$ a high] price ?an ! natural topazes4 ,( c\rse1 c>e has to be tak5 9 heat+ a m9]al to raise & l[] ! temp]ature sl[ly1 9 ord] to avoid sudd5 & unequal expansion or contraction1 :i* w\ld crack & ru9 ! specim51 z ! writ] le>n$ to 8 sorr[ ) ! fir/ topaz t he tri$ to p9k4 ,,spani% ,,topaz4 ,ano!r mat]ial t ga9s a m valuable color by heat treatm5t is ! smoky qu>tz ( ,spa91 :i*1 on be+ g5tly heat$1 yields ! s-call$ ,spani% topaz4 ,"s ame?y/s are alt]$ to a yell[ color by mild heat+4 ,too great a temp]ature completely decolorizes color$ qu>tz4 ,"s d>k qu>tz yields a ne>ly g>net r$ product1 aft] heat+4 ,,zircon4 ,slight increase 9 temp]ature causes _m ( ! zircons f ,ceylon to *ange m>k$ly 9 color4 ,an alcohol flame s]ves admirably to effect ! *ange1 c>e be+ tak5 to w>m up ! /one v gradually & to cool x sl[ly4 ,drafts %\ld be prev5t$1 z !y might sudd5ly cool ! /one & crack x4 ,"s zircons become completely :it5$ by ?is treatm5t4 ,at ! same "t !y increase m>k$ly 9 d5sity & 9 refractive index & ?us become ev5 m snappy & brilliant ?an :5 color$4 ,"o is tempt$ to suspect t ! space lattice ( ! cry/al has _h its /rata drawn clos] toge!r dur+ ! heat+ & left p]man5tly 9 a clos] ord] ( arrangem5t4 ,o!r zircons m]ely become light] color$ & less attractive4 ,"s ( ! :it5$ /ones aga9 become m or less color$ on exposure to /rong light4 ,ultra-violet light w sometimes re/ore ^! to a f9e deep color 9 a %ort "t4 ,! :it5$ zircon1 :5 f9ely cut 9 ! brilliant =m1 ) truly flat facets & %>p edges & ) a top angle ( ab\t #ci degrees & a back angle ( ab\t #dd degrees1 s closely resembles a diamond t x w deceive almo/ anyone on casual inspection4 ,! exp]t1 ev51 may be deceiv$1 if caught (f 8 gu>d4 ,! writ] has a f9e specim5 ( a little ov] "o c>at1 ) :i* he has deceiv$ _m jewel]s & pawnbrok]s1 & ev5 an import] or two4 ,if x is pres5t$ z a /one t closely resembles diamond y\r exp]t w say3 ,yes1 x is pretty good1 b x w\ld nev] fool me4 ,if1 h[ev]1 y cat* him (f 8 gu>d by sugge/+1 p]haps1 ,did y ev] see a diamond ) a poli%$ girdle81 !n he w look at x ) int]e/1 rem>k on its f9e color & make1 & nev] ?9k ( *all5g+ its "*4 ,! refractive index ( ! d5se type ( zircon is s high 7#a4ib-a4ih7 t x lights up well ov] mo/ ( ! surface ( ! brilliant :5 cut1 z above indicat$1 & does n %[ m>k$ly ! weak d>k c5t] %[n by :ite sapphire1 :ite topaz1 colorless qu>tz1 colorless b]yl1 & pa/e1 :5 se5 f ! side4 ,moreov]1 ! lu/] ( zircon is ne>ly adamant9e1 s ! exp]t does n miss ! cold metallic glitt] z he w\ld ) any o!r :ite /one4 ,! color disp]sion1 too1 is s high 7#hf z great z 9 diamond7 t ! zircon has consid]able fire1 & ?us ! casual h&l] is aga9 deceiv$4 ,a f9e :ite zircon is really pretti] ?an a poor diamond4 ,x _c comp>e1 h[ev]1 ) a f9e diamond4 ,x w\ld nev] d to let an exp]t see y\r zircon beside ev5 a fair diamond4 ,! zircon w\ld look sleepy4 ,x is only :5 no direct comp>ison is possible1 & :5 ! exp]t is n suspici\s1 t a zircon c deceive him4 ,( c\rse1 ! use ( ! sci5tific te/s ( ! e>li] lessons w1 at once1 detect ! "* ( a :it5$ zircon4 ,! h>dness is b #g4e1 ! refraction s /rongly d\ble t ! edges ( ! back facets appe> d\ble-l9$ :5 view$ ?r\gh ! table ) a l5s1 & ! specific gravity is #d4fi4 ,d\ble spots ( light appe> on ! c>d :5 ! sunlight-c>d te/ is appli$4 ,h5ce1 x is easy to detect zircon by any ( ^! te/s if !re is reason to suspect t x has be5 sub/itut$ = diamond4 ,,corundum ,,gems4 ,rubies ( /reaky color are said to be improv$ by c>eful heat+4 ,usually ruby und]goes a s]ies ( color *anges on be+ heat$1 b returns ?r\gh ! same s]ies 9 rev]se ord] on be+ cool$1 & f9ally resumes its orig9al color4 ,/rong heat+ w :it5 "s yell[ sapphire4 ,! au?or ?us obta9$ a :ite sapphire f a cry/al ( light yell[ mat]ial4 ,x is int]e/+ to note t ! corundum gems und]go m>k$ *ange 9 color "u ! influ5ce ( radium4 ,a regul> s]ies ( *anges is said to be produc$ 9 :ite sapphire by ?is means1 ! f9al color be+ yell[4 ,?is color may !n be remov$ by heat & ! s]ies run ?r\gh aga94 ,x is n /at$ t a f9e r$ has ev] be5 ?us obta9$4 ,p]haps ,nature1 by h] sl[] me?ods1 us+ ! fa9t traces ( radio-active mat]ial 9 ! rocks1 r$d5s ! corundum ( ,burmah at h] leisure1 & f9ally arrives at ! mu* s\ght pigeon blood color4 ,x is said t ! natives ( ,india h a leg5d to ! effect t ! :ite sapphires ( ! m9es are rip5+ rubies1 & t "o day !y w mature4 ,p]haps !y are n f> wrong4 ,,diamond4 ,diamonds ( yell[i% t9t may be improv$ 9 color by ! use ( high-p[] radium4 ,at pres5t ! latt] is s r>e & co/ly t !re is no evid5ce ( its comm]cial use = ?is purpose4 ,sci5ti/s h br\ght ab\t ! *ange to a light blue z an exp]im5t4 ,x is n yet kn[n :e!r ! *ange w be p]man5t4 ,p]haps "h aga9 ,nature has anticipat$ man's discov]y & made ! f9e blui%-violet ,brazilian diamonds 7:i* fluoresce to a deep violet "u an arc light1 & :i* %9e = a few mom5ts 9 ! d>k aft] exposure to light7 by associat+ !m = ages ) radio-active mat]ial4 ,"s ( ! ,african /ones also h ^! *>act]i/ics4 ,aside f ! *ange 9 ! color ( diamond t may be br\ght ab\t by means ( radium1 ! m9]al is extremely reluctant to alt] its color4 ,_m exp]im5t]s besides ! au?or h tri$ 9 va9 a ho/ ( exp$i5ts 9 ! hope ( f9d+ "s way to improve ! color ( diamond4 ,ab\t ! only noticeable alt]ation t ! au?or has be5 able to br+ ab\t 0 ^u a br[n diamond1 ! color ( :i* 0 made some:at light] & m a%5 by heat+ x 9 a curr5t ( hydrog5 gas to a l[ r$ heat4 ,,lesson ,,xxvii ,,pe>ls ,unlike ! gems t h be5 s f> consid]$1 ! pe>l is n a m9]al1 b is ( organic orig91 t is1 x is ! product ( a liv+ organism4 ,!re are two pr9cipal types ( molluscs :i* yield true pe>ls 9 comm]cial quantities4 ,! be/ kn[n ( ! fir/ type is ! s-call$ pe>l oy/] 7,meleagr9a m>g>itif]a74 ,! pe>l mussel ( fre% wat] /reams is ( ! second type 7,unio m>g>itif]a74 ,o!r species ( molluscs hav+ pe>ly l9+s to _! %ells may produce pe>ls1 b mo/ ( ! pe>ls ( comm]ce come f "o or ! o!r ( ! two v>ieties m5tion$4 ,,/ructure ,,( ,,pe>l4 ,! /ructure & mat]ial ( ! true pe>l mu/ be fir/ und]/ood 9 ord] to und]/& ! und]ly+ reasons = ! rem>kable beauty ( ?is gem4 ,pe>ls are compos$ p>tly ( ! m9]al sub/ance calcium c>bonate 7*emically ! same z m>ble7 & p>tly ( a t\gh1 horny sub/ance ( organic nature call$ con*iol94 ,! %ell ( ! pe>l-be>+ mollusc is also compos$ ( ^! two sub/ances4 ,calcium c>bonate may cry/allize 9 ei!r ( two =ms1 calcite or aragonite4 ,9 m>ble we h calcite4 ,9 ! out] portions ( ! %ell ( ! pe>l oy/] ! calcium c>bonate is 9 ! =m ( calcite1 b 9 ! inn] nacre\s l9+ & 9 ! pe>l itself ! m9]al is pres5t z aragonite4 ,?is is deposit$ by ! mollusc 9 v ?9 cry/all9e lay]s 9 ! horny lay]s ( con*iol91 s t ! l9+ ( ! %ell is built ( approximately p>allel lay]s ( m9]al & ( animal sub/ance4 ,9 ! normal %ell ?is is all t takes place1 b 9 ! case ( a mollusc ^: int]ior is invad$ by any small s\rce ( irritation1 su* z a bor]1 or a gra9 ( s&1 or o!r bit ( =eign mat]ial1 a process ( alt]nate deposit ( con*iol9 & ( aragonite goes on ^u ! invad+ matt]1 ?us =m+ a pe>l4 ,! pe>l is built 9 lay]s l an onion4 ,9 %ape x may be sph]ical1 or pe>-%ap$1 or button-%ap$ or ( any less regul> %ape ?an ^!4 ,! regul> %apes are m highly valu$4 ,! sph]ical %ape is ( greate/ value1 o!r ?+s be+ equal4 ,next comes ! drop or pe> %ape1 !n ! button %ape1 & aft] ^! ! ho/ ( irregul> %apes kn[n to ! jewel] z b>oques4 ,! riv] man :o ga!rs mussels calls ^! odd-%ap$ pe>ls slugs4 ,let u n[ attempt to und]/& h[ ! beautiful lu/] & iridesc5ce ( ! pe>l are relat$ to ! lay]-l /ructure ( ! gem4 ,9 ! fir/ place1 x %\ld be und]/ood t bo? con*iol9 & aragonite are transluc5t1 t is1 !y pass light to a c]ta9 ext5t4 ,! lay]s be+ exce$+ly ?91 light c p5etrate a consid]able numb] ( !m if n o!rwise deflect$ f its c\rse4 ,we ?us obta9 reflections n m]ely f ! out] surface ( a pe>l1 b f lay] aft] lay] )9 ! gem & all ^! reflections rea* ! eye 9 a bl5d$ reflection ( great beauty4 ,! lu/] ( a pe>l is !n n purely a surface lu/] 9 ! usual s5se ( t t]m1 b x is a lu/] due to _m sup]pos$ surfaces4 ,x is s diff]5t f o!r types ( lu/] t we describe x m]ely z pe>ly lu/] ev5 ?\gh we f9d x 9 "s o!r mat]ial1 z1 = example 9 c]ta9 sapphires1 9 :i* x is due to a simil> lay]-l arrangem5t ( /ructure4 ,,ori5t4 ,! f95ess ( ! lu/] ( a pe>l1 or z is said 9 ! trade1 ! ori5t1 dep5ds ^u ! numb] ( lay]s t take "p 9 ! reflection1 & ?is numb] 9 turn dep5ds ^u ! transluc5cy ( ! mat]ial & ! ?9ness ( ! lay]s4 ,v f9e pe>ls usually h v _m1 v ?9 lay]s tak+ "p 9 ! reflection4 ,! degree ( transluc5cy1 consid]$ ap>t1 is sometimes call$ ! wat] ( ! pe>l4 ,9 addition to _! beautiful lu/]1 _m pe>ls display iridesc5ce1 & ?is is due 9 "p1 z 9 ! case ( ! pe>ly l9+ ( ! %ell 7"m ( pe>l7 to ov]lapp+ ( successive lay]s1 l ! ov]lapp+ ( %+les on a ro(4 ,?is gives rise to a l9$ surface1 mu* l ! diffraction grat+ ( ! physici/1 :i* is made by rul+ a glass plate ) ?\s&s ( p>allel l9es to ! in*4 ,su* a grat+ produces wond]ful spectra1 9 :i* ! ra9b[ colors are widely sep>at$ & v vivid4 ,! pr9cipal on :i* ?is sep>ation ( light dep5ds is kn[n z diffraction & _c be expla9$ "h1 b a simil> effect takes place :5 light falls on ! naturally rul$ surface ( a pe>l & helps produce ! play ( colors kn[n z iridesc5ce4 ,! ?9 lay]s !mselves also help to produce ! iridesc5ce by int]f]5ce ( light mu* z 9 ! case ( ! opal1 :i* has already be5 discuss$4 ,,color4 ,hav+ expla9$ ! cause ( ! ori5t & wat] ( pe>ls1 ! color mu/ next be consid]$4 ,pe>ls may be _h ( almo/ any color1 b ! majority ( f9e pe>ls are :ite1 or ne>ly s4 ,! f9e ,ori5tal pe>ls frequ5tly h a creamy t9t4 ,among fre% wat] pe>ls ! creamy t9t is less (t5 se51 b f9e p9k t9ts occur4 ,occasionally a black pe>l is f\nd & on acc\nt ( its r>ity comm&s a price ne>ly z great z t obta9able = a :ite pe>l ( simil> size & quality4 ,! value ( pe>ls dep5ds ^u sev]al diff]5t factors & x is f> f an easy matt] to e/imate ! value ( a f9e specim54 ,x is mu* easi] to grade & e/imate ! value ( diamonds ?an to d ! same = pe>ls1 & x is only by long & intimate acqua9tance ) ! pe>ls !mselves t "o c hope to become exp]t 9 decid+ values4 ,!re are1 h[ev]1 sev]al g5]al factors t gov]n ! value ( pe>ls4 ,*ief among ^! are3 #a1 ,ori5t2 #b1 ,color2 #c1 ,texture or ,sk92 #d1 ,%ape & ,size4 ,,factors ,,gov]n+ ,,! ,,value ,,( ,,pe>ls4 ,tak+ up ea* ( ^! factors 9 turn1 x may be said ( ! fir/ t unless a pe>l has t f9e ke5 lu/] kn[n z a f9e ori5t1 x is ( b limit$ value4 ,no matt] :at ! size1 or h[ p]fect ! %ape1 x is no?+1 if dead & lu/]less4 ,to h great value ! gem mu/ gleam ) t s(t b lively lu/] peculi> to f9e specim5s ( pe>l4 ,) v>iations 9 ori5t g wide v>iations 9 value4 ,z to color1 ! *oice/ pe>ls are pure :ite or delicate rose p9k or creamy :ite4 ,pe>ls 9 ^! %ades c be _h 9 numb]s & ^! colors are :at might be call$ regul> colors4 ,fancy-color$ pe>ls h peculi> & irregul> values1 dep5d+ a good deal ^u r>ity & ^u ! obta9+ ( a cu/om] = an odd color4 ,f9e p9k & f9e black pe>ls are examples ( ! type t is meant "h4 ,to be v valuable a pe>l mu/ h a smoo? ev5 sk91 t is1 ! texture ( its surface mu/ be ev5 & regul>4 ,x mu/ n h pits or scrat*es or wr9kles1 or little rais$ spots ^u x1 or any cracks 9 x4 ,9 connection ) ?is topic ( sk91 x may be m5tion$ t x is sometimes true t a pe>l ( bad sk9 or ( poor lu/] may be improv$ m>k$ly by peel+ x1 z ! process is call$4 ,z 0 said above1 a pe>l is built 9 lay]s mu* l an onion1 & x c (t5 be peel$1 t is1 "o or m lay]s c be remov$1 ?us expos+ fre% lay]s b5ea?1 ^: texture & lu/] may be bett] ?an ^? ( ! orig9al outside lay]4 ,,peel+ ,a ,,pe>l4 ,possibly an anecdote ( an actual case may s]ve be/ to expla9 ! me?od by :i* peel+ is sometimes accompli%$4 ,! writ] 0 once at ,v9c5nes1 ,ind41 on bus9ess1 & !re became acqua9t$ ) a pe>l buy] :o 0 /opp+ at t place to buy fre% wat] pe>ls & slugs f ! riv]m5 :o ga!r ! mussels = ! sake ( _! %ells4 ,! latt] are made into pe>l buttons = clo?+4 ,x happ5$ t ! pe>l buy] _h accumulat$ "s tw5ty-eight ounces ( slugs & a numb] ( pe>ls & 0 leav+ on ! same tra9 ) ! au?or1 :o %>$ 8 seat ) him4 ,:ile we 7 look+ ov] ! slugs toge!r ! pe>l buy] put 8 h& 9 8 pocket & drew out a five-doll> bill :i* he unroll$1 expos+ a pe>l ( ab\t six gra9s1 well %ap$1 b ( r dead lu/]4 ,rem>k+ t he _h paid b #d = x & t he _h roll$ x up 9 ! bill = safe keep+ until he got "t to peel x1 he took out a small p5knife1 op5$ "o ( ! blades1 put a c\ple ( kid glove f+] tips on ! ?umb & fir/ f+] ( 8 left h& & proce$$ to peel ! pe>l on ! mov+ tra94 ,hold+ 8 two h&s toge!r to /eady !m1 he press$ ! edge ( 8 knife blade aga9/ ! pe>l until ! h>d] /eel _h p5etrat$ /raight d[n ?r\gh "o lay]4 ,!n ) a flak+1 lat]al motion he flak$ (f a "p ( ! out] sk94 ,bit by bit all ( ! out] lay] 0 flak$ (f1 & t1 too1 )\t appreciably scrat*+ ! next lay]1 s great 0 ! work]'s skill4 ,:5 ! pe>l 0 completely peel$ x 0 g5tly rubb$ ) ?ree grades ( poli%+ pap]1 ea* f9] ?an ! previ\s "o1 & !n ! writ] 0 all[$ to exam9e x4 ,! appe>ance _h be5 mu* improv$1 al?\gh x 0 n ( extremely f9e quality ev5 :5 peel$4 ,"u a high p[] magnifi] sc>cely a trace ( ! peel+ c\ld be se54 ,! value ( ! #d pe>l _h be5 rais$ to at lea/ #ajj & n _m m9utes _h be5 requir$ = ! *ange4 ,a sl[] & m labori\s1 b saf]1 process ( peel+ a pe>l1 consi/s 9 g5tly rubb+ ! surface ) a v f9e1 r s(t1 abrasive p[d] until all ( ! out] sk9 has be5 ?us worn away4 ,( c\rse1 9 _m su* cases no bett] sk9 ?an ! out] "o c\ld be f\nd & disappo9tm5t w\ld result f ! peel+ ( su* a pe>l4 ,x %\ld be add$ t x w n d to try to peel a "p ( a pe>l 9 ord] to remove an excresc5ce1 = !n "o w\ld inevitably cut across ! lay]s1 expos+ _! edges1 & su* a surface looks1 :5 poli%$1 mu* l a pe>l button1 b n l a pe>l4 ,9 ?is connection may be m5tion$ ! widespread belief on ! "p ( ! public t ! concretions f\nd 9 ! common edible oy/] c be poli%$ by a lapid>y1 z a r\gh preci\s /one c be improv$ by ! latt]1 & t a f9e pe>l w result4 ,x is frequ5tly necess>y = jewel]s to :om su* pe>ls are br\ght1 to undeceive ! p]son br++ !m & to tell him t only ^? molluscs t h a beautiful pe>ly l9+ to _! %ells are capable ( produc+ true pe>ls & t ! latt] require no assi/ance f ! lapid>y4 ,,%ape4 ,to return to ! topic ( factors gov]n+ ! value ( pe>ls1 ! %ape ( ! pe>l makes a va/ diff]5ce 9 ! value4 ,p]fectly sph]ical pe>ls are mo/ highly valu$ & closely foll[+ come ^? ( drop or pe> %ape1 z ?is %ape l5ds itself nicely to ! mak+ ( p5dants4 ,oval or egg-%ap$ pe>ls are also good4 ,aft] ^! come ! button %apes1 9 :i* "o side is flatt5$4 ,pe>ls ( irregul> %ape are mu* less highly valu$4 ,! irregul>-%ap$ pe>ls are call$ b>oque pe>ls 9 ! trade4 ,! riv]m5 engag$ 9 ! fre% wat] pe>l fi%]y call !m slugs4 ,"s ( ! m regul> ( ^! are call$ nuggets4 ,o!rs are t]m$ spikes because ( _! po9t$ %ape1 & /ill o!rs are call$ w+ pe>ls on acc\nt ( _! resemblance to a bird's w+4 ,mo/ ( ! b>oques are too irregul> 9 %ape to h any special "n apply+ to _! =m4 ,,weight4 ,aft] ori5t1 color1 sk91 & %ape h be5 consid]$1 size or weight f9ally det]m9es ! value4 ,pe>ls are sold by an arbitr>y unit ( weight kn[n z ! pe>l gra94 ,x is n equal to ! gra9 avoirdupois1 b is "o f\r? ( a diamond c>at4 ,z ! new metric c>at is "o fif? ( a gram & z !re are #ae4dc avoirdupois gra9s 9 a gram1 x is se5 at once t !re are b #c4jh real gra9s 9 a c>at r ?an f\r4 ,?us ! pe>l gra9 is slightly light] ?an ! avoirdupois gra94 ,s9ce l>ge1 f9e pe>ls are exce$+ly r>e1 ! value m\nts ) size mu* m rapidly ?an is ! case ) any o!r gem2 9 fact1 ! value increases z ! squ>e ( ! weight4 ,= example1 let u consid] two pe>ls1 "o ( "o gra9 weight1 ! o!r ( two gra9s1 & bo? ( ! same grade z to quality4 ,if ! small] is wor? say #b p] gra91 !n ! l>g] is wor? #b #b 7! squ>e ( ! weight7 times #b 7! price p] gra9 base1 z x is call$ 9 ! trade71 :i* totals #h4 ,a f\r-gra9 pe>l ( ?is grade w\ld be wor? #d #d #b #cb1 etc4 ,?us x is se5 t ! price increases v rapidly ) increase 9 weight4 ,,price ,,p] ,,gra9 ,,base4 ,"s ( ! l[] grades ( pe>ls 9 small sizes are sold by ! gra9 /raight1 t is1 ! price p] gra9 is m]ely multipli$ by ! weight 9 gra9s to get ! value1 j z ! price p] c>at w\ld be multipli$ by ! numb] ( c>ats to get ! value ( a diamond4 ,?is me?od ( figur+ ! value ( pe>ls is us$ only = ! *eap] grades & small sizes1 h[ev]1 & ! me?od fir/ expla9$1 ! calculation p] gra9 base1 is ! "o 9 univ]sal use = f9e gems4 ,v f9e exceptional gems may be sold at a l>ge price = ! piece1 reg>dless ( ! weight4 ,x is int]e/+ to note 9 ?is connection t ,tav]ni]1 ! ,fr5* gem m]*ant ( ! sev5te5? c5tury1 tells u t 9 8 day ! price ( l>ge diamonds 0 calculat$ by a me?od simil> to t :i* we n[ use = pe>ls1 t is1 ! weight 9 c>ats 0 squ>$ & ! product multipli$ by ! price p] c>at4 ,su* a me?od w\ld give f> too high a price = diamonds to-day4 ,,! ,,high ,,price ,,( ,,f9e ,,pe>ls4 ,?is sugge/s ! ?\ght t pe>ls ( f9e quality & great size are ! mo/ co/ly ( all gems to-day & yet !re seems to be no halt+ 9 ! dem& = !m4 ,9 fact1 ,am]ica is only j beg9n+ to get int]e/$ 9 pe>ls & is com+ to e/eem !m z !y h long be5 e/eem$ 9 ! ,ea/ & 9 ,europe4 ,^? :o h ?\ght t ! advance 9 ! prices ( diamonds 9 rec5t ye>s w soon put !m at prohibitive rates %\ld consid] ! enorm\s prices t h be5 obta9$ & are be+ obta9$ = f9e pe>ls4 ,9 ord] to facilitate ! calculat+ ( prices ( pe>ls1 tables h be5 comput$ & publi%$ giv+ ! values ( pe>ls ( all sizes at diff]5t prices p] gra9 base1 & sev]al times ^! tables h be5 outgr[n1 & new ones1 runn+ to high] values1 h be5 made4 ,! pres5t tables run to #ej p] gra9 base4 ,!re is mu* ju/ification = ! high prices dem&$ & paid = l>ge & f9e pe>ls4 ,su* gems are really exce$+ly sc>ce4 ,^? :o1 z boys1 h op5$ hundr$s ( riv] mussels only to f9d a v few small1 badly mis%ap5 slugs w realize t x is only "o mollusc 9 a v l>ge numb] t conta9s a f9e pe>l4 ,moreov]1 l ! bison & ! wild pigeon1 ! pe>l-be>+ molluscs may be greatly dim9i%$ 9 numb]s or ev5 ext]m9at$ by ! gre$ ( man & 8 fe>fully de/ructive me?ods ( h>ve/+ nature's productions4 ,9 fact1 ! fi%]ies h be5 dw9dl+ 9 yield = "s "t1 & mo/ ( ! f9e pe>ls t are m>ket$ are old pe>ls1 already drill$1 f ! treasuries ( ,ea/]n pot5tates1 :o h be5 =c$ by necessity to accept ! high prices (f]$ by ! ,we/ = "p ( _! treasures4 ,9 ,india1 pe>ls h long be5 acceptable collat]al = loans1 & _m f9e gems h come on ! m>ket aft] failure ( ! own]s to repay su* loans4 ,hav+ consid]$ ! factors be>+ on ! value ( pe>ls1 we w next consid] briefly _! physical prop]ties4 ,! specific gravity is less def9ite ?an ) m9]als & v>ies betwe5 #b4fe & #b4gj4 ,x may be ev5 high] = p9k pe>ls4 ,,physical ,,prop]ties4 ,9 h>dness pe>ls also v>y1 rang+ betwe5 #c-a_/b & #d on ,mohs's scale4 ,!y are ?us v s(t & easily worn or scrat*$ by h>d usage4 ,a case %[+ ! r rapid we>+ away ( pe>ls rec5tly came to ! att5tion ( ! writ]4 ,a p5dant 9 ! %ape ( a ,lat9 cross _h be5 made ( r\nd pe>ls :i* _h be5 drill$ & /rung on two sl5d] gold rods to =m ! cross4 ,! pe>ls 7 free to rotate on ! wires4 ,aft] a p]iod ( "s tw5ty or m ye>s ( we> ! pe>ls _h all become di/9ctly cyl9drical 9 %ape1 ! rubb+ aga9/ ! g>m5ts ov] :i* ! p5dant _h be5 worn hav+ be5 suffici5t to gr9d away ! s(t mat]ial to t ext5t4 ,! lu/] 0 /ill good1 ! pe>ls hav+ virtually be5 peel$ v sl[ly by abrasion4 ,,c>e ,,( ,,pe>ls4 ,?is example sugge/s ! great c>e t %\ld be tak5 by own]s ( f9e pe>ls to prev5t undue rubb+ or we> ( ^! valuable b n extremely durable gems4 ,!y %\ld be c>efully wip$ aft] be+ worn to remove du/ & !n put away 9 a tightly clos$ case4 ,pe>ls %\ld nev] be all[$ to come 9 contact ) any acid1 n ev5 weak acids l lemonade1 or pun* or v9eg>1 z1 be+ l>gely calcium c>bonate !y are v easily act$ ^u by acids1 & a m]e t\* ) an acid might ru9 ! surface lu/]4 ,be+ p>tly organic 9 nature1 pe>ls are n ev]la/+1 b mu/ ev5tually decay1 z is %[n by ! p[d]y condition ( v old pe>ls t h be5 f\nd ) mummies or 9 anci5t ru9s4 ,! organic matt] has yield$ to bact]ial attack & decay$1 leav+ only ! p[d]y m9]al matt] beh9d4 ,z heat & moi/ure are ! conditions mo/ conducive to ! gr[? ( bact]ia1 & h5ce to decay1 x w\ld foll[ t f9e pe>ls %\ld be kept 9 a dry cool place :5 n 9 use4 ,,lesson ,,xxviii ,,cultur$ ,,pe>ls ,,& ,,imitations ,,( ,,pe>ls ,,cultur$ ,,pe>ls4 ,l all v valuable gems1 pe>ls h /imulat$ ! +5uity ( man to attempt to make imitations t w\ld pass = g5u9e4 ,p]haps ! mo/ +5i\s1 z well z ! mo/ natural look+ product1 is ! cultur$ pe>l4 ,?is is really natural pe>l on mu* ( its ext]ior1 b artificial )9 & at ! back4 ,9 ord] to br+ ab\t ?is result ! ,japanese1 :o orig9at$ ! pres5t comm]cial product1 b :o probably borr[$ ! orig9al idea f ! ,*9ese1 call to _! assi/ance ! pe>l oy/] itself4 ,! oy/]s are g5tly op5$1 small hemisph]ical discs ( "m-(-pe>l are introduc$ betwe5 %ell & mantle & ! oy/] replant$4 ,! =eign mat]ial is coat$ by ! oy/] ) true pe>ly lay]s z usual1 & aft] sev]al ye>s a suffici5tly ?ick accumulation ( pe>ly lay]s is ?us deposit$ on ! nucleus s t ! oy/] may be ga!r$ & op5$ & ! cultur$ pe>l remov$ by saw+ x out f ! %ell to :i* x has become atta*$4 ,to ! base is !n neatly cem5t$ a piece ( "m-(-pe>l to complete a ne>ly sph]ical %ape1 & ! portions ( ! surface t h n be5 cov]$ ) true pe>l are !n poli%$4 ,! product1 :5 set 9 a prop] pe>l m\nt+1 is q conv9c+ & really beautiful4 ,z ! "t dur+ :i* ! oy/] is all[$ to "w ^u ! cultur$ pe>l is d\btless f> less ?an is requir$ = ! gr[? ( a l>ge natural pe>l1 ! numb] ( lay]s ( true pe>ly mat]ial is consid]ably small] ?an ! numb] ( lay]s t take "p 9 ! multiple reflections expla9$ 9 ! previ\s lesson1 & h5ce ! ori5t ( ! cultur$ pe>l is nev] equal to t ( a f9e true pe>l4 ,x is frequ5tly v good h[ev]1 & = uses t d n dem& exposure ( ! :ole surface ( ! pe>l1 ! cultur$ pe>l supplies a sub/itute = g5u9e pe>ls ( mod]ate quality & price4 ,! back p>ts ( ! cultur$ pe>l1 be+ only poli%$ "m-(-pe>l1 h ! appe>ance ( ! ord9>y pe>l button1 r ?an t ( true pe>l4 ,,imitations ,,( ,,pe>ls4 ,aside f ^! half artificial cultur$ pe>ls1 ! out & out imitations ( pe>ls t h be5 mo/ successfully sold are ( two g5]al types1 fir/ ,roman pe>ls1 &1 second1 ,inde/ructible pe>ls4 ,! ,roman pe>ls are made holl[ & aft]w>d wax fill$1 ! ,inde/ructible pe>ls h solid enamel bases4 ,9 bo? types ! pe>ly appe>ance is obta9$ by l9+ ! int]ior1 or coat+ ! ext]ior1 ) m or less num]\s lay]s ( :at is kn[n z nacre or "s times z ess5ce d'ori5te4 ,?is is prep>$ f ! scales ( a small fi% f\nd 9 ! ,nor? ,sea & 9 ,russia4 ,! scales are remov$ & treat$ ) c]ta9 solutions :i* remove ! silv]y p[d] f ! scales4 ,! nacre is !n prep>$ f ?is p[d]4 ,! f95ess ( ! pe>ly effect becomes great] z ! prep>ation ages1 s v f9e imitations are usually made f old nacre4 ,! effect is also bett] ! l>g] ! numb] ( successive lay]s us$4 ,! artificial pe>l ?us resembles ! true pe>l 9 ! physical causes = ! beautiful effect4 ,9 "s cases ! ,roman pe>l has a true iridesc5ce :i* is produc$ by burn+ colors into ! holl[ enamel bead4 ,"s ( ! inde/ructible pe>ls are made ov] beads ( opalesc5t glass1 ?us imp>t+ a f9] effect to ! f9i%$ product4 ,:ile ! *eap] grades ( inde/ructible pe>ls h b ?ree or f\r lay]s ( nacre1 "s ( ! f9e ones h z _m z ?irty or m4 ,! e>li] inde/ructible pe>ls 7 made ) a coat+ mat]ial :i* 0 easily affect$ by heat1 or by wat]1 or by p]spiration1 z a gelat9e-l siz+ 0 includ$ 9 x4 ,! m rec5t product has a m9]al b9d] :i* is n ?us affect$1 s t ! pe>ls are really ab\t z durable z natural ones1 & w at lea/ la/ a lifetime if us$ ) prop] c>e4 ,l f9e natural pe>ls1 ! f9e imitations %\ld be wip$ aft] use & c>efully put away4 ,!y %\ld also be re/rung occasionally1 z %\ld real pe>ls bo? to prev5t loss by ! break+ ( ! /r+ & because ! /r+ becomes soil$ aft] a "t1 & ?is hurts ! appe>ance ( ! jewel4 ,! ,roman type ( imitation w n /& mu* heat1 z ! wax core w\ld melt & run out4 ,,te/+ ,,imitations ,,( ,,pe>ls4 ,z ! mak+ ( imitations ( pe>ls is ma9ly h&-"w & z _m treatm5ts are requir$ = ! be/ imitations1 fairly high prices are dem&$ = ^! bett] products1 & ! appe>ance & p]man5cy w>rant su* prices4 ,! be/ imitation pe>ls are really v difficult ( detection except by close exam9ation4 ,!y w n1 ( c\rse1 /& inspection "u a high magnification4 ,artificial pe>ls may also be detect$ by _! incorrect specific gravity1 by _! incorrect degree ( h>dness1 & 9 ! case ( ! holl[ pe>ls by mak+ a t9y ink spot ^u ! surface ( ! pe>l & look+ at x ?r\gh a l5s4 ,a reflection ( ! spot f ! inside surface ( ! bead w appe> beside ! spot itself if ! pe>l is ( ! ,roman type4 ,! artificial pe>ls s f> describ$ are high class products4 ,"s ( ! v *eap & poor imitations are m]ely solid1 or holl[1 glass or enamel beads :i* h be5 made slightly pe>ly1 ei!r by add+ v>i\s mat]ials to ! glass or enamel :5 x 0 made1 or by crudely coat+ ! beads )\t or )9 ) wax conta9+ *eap nacre4 ,,lesson ,,xxix ,,! ,,use ,,( ,,balances ,,& ,,! ,,unit ,,( ,,weight ,,9 ,,use ,,= ,,preci\s ,,/ones ,z preci\s /ones are almo/ always sold by weight1 & z ! value at /ake is frequ5tly v great1 x is almo/ z necess>y = a gem m]*ant1 z x is = ! *emi/1 to h delicate balances & to keep !m 9 good ord] & to use !m skillfully4 ,a g5]al und]/&+ ( ! unit ( weight 9 use = preci\s /ones & h[ x is relat$ to o!r /&>d weights is also necess>y to ! gem deal]4 ,we w !re=e consid] 9 ?is lesson ! use & c>e ( balances & ! nature & relative value ( ! unit ( weight = preci\s /ones4 ,,delicate ,,balances ,,ne$$4 ,z x is necess>y1 on acc\nt ( _! great value1 to weigh "s gems1 su* z diamonds1 em]alds1 rubies1 etc41 ) accuracy to at lea/ ! "o hundr$? "p ( a c>at 7:i* is r\ghly 9 ! neighborhood ( #a_/ae1jjj ( an ounce avoirdupois71 balances ( v delicate & accurate con/ruction are a necess>y "p ( ! equipm5t ( e gem m]*ant4 ,:ile portable balances ( a fair degree ( accuracy are to be _h1 ! be/ & sure/ balances are sub/antially con/ruct$ & h\s$ 9 glass cases1 mu* z are ^? ( ! analytic *emi/1 :i* mu/ d ev5 f9] weigh+4 ,! case protects ! balance f du/ & dirt & prev5ts ! action ( air curr5ts dur+ ! weigh+4 ,! balance itself has v delicate knife edges1 sometimes ( agate1 sometimes ( h>d5$ /eel1 & ^! knife edges re/1 :5 9 use1 on a block ( agate or /eel1 s t !re is a m9imum am\nt ( friction4 ,:5 n 9 use ! balance beam & knife edges are lift$ f ! block & held firmly by a metal arm1 or else1 z is ! case ) "s balances1 ! po/ support+ ! block is l[]$1 leav+ ! beam & knife edges out ( contact ) x4 ,! object ( ?is sep>ation is to prev5t any r\gh contact betwe5 ! knife edges & ! block on :i* !y re/4 ,advantage %\ld always be tak5 ( ?is device :5ev] any fairly heavy load is put on or tak5 (f ( ei!r pan1 z ! sudd5 tipp+ ( ! beam might *ip ! knife edges if n support$4 ,:5 ! load is ne>ly balanc$ !re may be no h>m 9 c>efully add+ or remov+ small weights :ile ! knife edges are re/+ on ! block1 b ev5 !n x is saf] to l[] ! beam & pans4 ,x %\ld be ne$less to /ate t z level & rigid a support %\ld be _h = "o's balance z circum/ances p]mit4 ,,me?od ,,( ,,use ,,( ,,balances4 ,be=e us+ a balance "o %\ld see t ! pans are clean1 t ! base ( ! balance is prop]ly level$ 7! bett] balances h a _s level atta*$7 & t ! pans balance ea* o!r )\t load4 ,:5 slightly out ( balance ! defect may be adju/$ by unscrew+ ! little adju/+ nut at ! end ( ! beam t is too light1 or by screw+ 9 ! nut at ! opposite end4 ,hav+ se5 t ! adju/m5t is p]fect ! pans %\ld be l[]$ & ! object to be weigh$ plac$ on ! left-h& pan 7because a "r-h&$ p]son w f9d x h&i] to h&le 8 weights on ! "r-h& pan74 ,"o %\ld next guess z ne>ly z possible ! weight ( ! /one & place well back on ! "r-h& pan ! weight t he ?9ks comes ne>e/ to t ( ! /one4 ,if ! weight is too heavy ! next light] weight %\ld replace x4 ,small] weights %\ld be add$ until a p]fect balance is _h1 ! small weights be+ neatly arrang$ 9 ! ord] ( _! size1 9 ord] to m rapidly c\nt !m :5 ! /one is balanc$4 ,?is is ! case :5 ! po9t] sw+s approximately equal di/ances to ! "r & to ! left & !re is !n no ne$ to wait = x to come to re/ 9 ! c5t]4 ,x is well to c\nt ! weights z !y lie on ! pan 7:i* is easily done if !y h be5 arrang$ 9 desc5d+ ord] ( size z sugge/$ above7 !n write d[n ! total1 & on remov+ ! weights c\nt al\d z !y are replac$ 9 ! box & note if ! total *ecks t :i* 0 writt5 d[n4 ,x may seem unnecess>y to be s c>eful 9 ?is matt]1 b x is bett] to be ov]-c>eful ?an to make a mi/ake :]e e hundr$? ( a c>at may mean f "o to five or six doll>s or m4 ,no deal] c af=d to h a /one t he has sold prove to be light] ?an he has /at$ x to be4 ,"o %\ld be at lea/ )9 "o "o-hundr$? ( a c>at ( ! correct weight4 ,x %\ld be unnecess>y to add t accurate weights %\ld nev] be h&l$ ) ! f+]s4 ,ivory tipp$ =ceps are be/ = h&l+ ! weights4 ,! =ceps commonly us$ = h&l+ diamonds w1 9 "t1 we> away ! weights by scrat*+ !m s t !y w weigh mat]ially less4 ,unless ! weights are ( plat9um or plat$ ) gold1 ! p]spiration ( ! h&s w\ld cause !m to oxidize & ga9 9 weight4 ,x w\ld be well to disc>d ! small] weights1 :i* are mo/ 9 use1 e few ye>s & obta9 new & accurate ones4 ,9 case ?is is n done "o %\ld at lea/ h ! weights *eck$ aga9/ o!rs kn[n to be ( /&>d weight4 ,any *emi/ w h balances & weights f> m accurate ?an ! be/ 9 use = preci\s /ones & w gladly *eck ! weights ( a gem deal] = a mod]ate fee4 ,to *eck ! accuracy ( y\r balance1 *ange ! /one & weights to opposite pans1 9 :i* case !y %\ld /ill balance4 ,"o %\ld nev] ov]load a balance1 bo? because ! balance might be injur$ & because ! relative accuracy decreases z ! load increases4 ,if ! weight ( a p>cel ( /ones heavi] ?an ! total ( ! weights provid$ ) ! balance is desir$1 ! p>cel %\ld be divid$ & weigh$ 9 p>ts4 ,:ile _m deal]s neglect "s ( ! precautions above sugge/$ & someh[ get along1 yet x is saf] to use c>e & to h correct te*nique 9 ! h&l+ ( "o's balances4 ,hav+ indicat$ a few ( ! ref9em5ts ( me?od 9 weigh+ we w next consid] ! unit ( weight 9 use = preci\s /ones & see h[ x is relat$ to o!r units ( weight & 9 :at mann] x is subdivid$4 ,,! ,,unit ,,( ,,weight ,,= ,,preci\s ,,/ones4 ,! pres5t unit = preci\s /ones 9 ! ,unit$ ,/ates is ! metric c>at4 ,mo/ ( ! m progressive c\ntries h 9 rec5t ye>s agre$ ^u ! use ( ?is unit4 ,its use 9 ! ,unit$ ,/ates became g5]al ,july #a1 #aiac4 ,x is by def9ition exactly "o fif? ( a gram 7! unit ( weight ( ! ,metric ,sy/em ( weights & measures74 ,its relation to ! gra9 is t !re are #c4jh gra9s 9 ! metric c>at4 ,! c>at 9 use 9 ?is c\ntry up to a few ye>s ago 0 ab\t #b-a_/b heavi] ?an ! pres5t metric c>at4 ,x 0 equal to 4#bjec grams in/ead ( 4#bjjj grams 7#a_/e gram74 ,! c>ats ( c\ntries n us+ ! metric c>at v>y consid]ably1 b yet approximate ! metric c>at some:at ne>ly4 ,?us1 t 9 use 9 ,great ,brita9 0 4#bjec g41 9 ,am/]dam 4#bjeg g41 9 ,b]l9 4#bjedd g41 9 ,lisbon 4#bjege g41 & 9 ,flor5ce #j4aigb g4 ,! latt] 0 ! only "o t 0 "u ! metric c>at4 ,! *ange to ! metric c>at 0 desirable1 z x unifi$ ! practice ( weigh+1 :i* n only v>i$ 9 diff]5t c\ntries1 b ev5 9 ! same c\ntry4 ,?us !re 0 no v exact agreem5t among ! mak]s ( diamond weights 9 ! ,unit$ ,/ates prior to ! adoption ( ! metric c>at4 ,"o man's c>at 0 a bit heavi] or light] ?an ano!r's4 ,) a def9ite & simple relation%ip to ! /&>d gram !re is n[ no excuse = any v>iation 9 weights4 ,! ,bureau ( ,/&>ds at ,wa%+ton af=ds manufactur]s e facility = /&>diz+ _! weights4 ,,! ,,decimal ,,sy/em ,,( ,,subdivision ,,( ,,! ,,c>at4 ,) ! adoption ( ! metric c>at ! cu/om ( express+ p>ts ( a c>at 9 common fractions ^: d5om9ators 7 p[]s ( ! numb] #b 7#a_/b1 #a_/d1 #a_/h1 #a_/af1 #a_/cb1 #a_/fd7 0 disc>d$ z awkw>d & sl[ = computation & ! decimal sy/em ( subdivision 0 adopt$4 ,?us ! metric c>at is divid$ into t5?s & "o hundr$?s4 ,x is cu/om>y1 h[ev]1 to sum up ! "o hundr$?s & express !m z ! total numb] ( "o hundr$?s & n to express !m z t5?s4 ,?us1 a /one ( #b4eg c>ats is said to weigh two & fifty-sev5 hundr$?s c>ats4 ,! decimal sy/em ( subdivision ( ! c>at makes ! figur+ ( values simpl] :]e no tables are h&y4 ,( c\rse1 new tables 7 at once prep>$ :5 ! new c>at 0 adopt$ & !y af=d a rapid means ( asc]ta9+ ! value ( a /one ( any weight :5 ! price p] c>at is kn[n4 ,%\ld x become necess>y to conv]t ! weight ( a /one f its expression 9 ! old sy/em to t ( ! new1 "o ne$ only get #a4jb-a_/b ( ! old weight4 7,! old c>at 0 approximately 4#bje g41 :ile ! new "o is 4#bjj g4 ,h5ce "o old c>at 4#bje 4#ajb-a_/b is ---- -------- #ajb-a_/b ( a new "o47 4#bjj 4#ajj ,,me?od ,,( ,,conv]t+ ,,weights4 ,if ! old weight has fractions ^! %\ld fir/ be *ang$ to decimals = conv5i5ce4 ,= example1 suppose x is wi%$ to *ange #b-a_/d #a_/af old c>ats to metric c>ats4 #a_/d 4#be & #a_/af 4#jfbe4 ,h5ce #b-a_/d #a_/af #b4cabe4 ,n[ get #ajb-a_/b ( ?is3 7#b4cabe #a4jbe #b4cg metric c>ats74 ,if1 = any reason "o %\ld ne$ to *ange f metric c>ats to old ,u4 ,s4 c>ats "o %\ld multiply by 4#igef 7 4#bjj g4 7 7 ------- 4#igef 7 7 4#bje g4 7 ,z 0 said 9 ,lesson ,,xxv41 pe>ls are sold by ! pe>l gra91 :i* is arbitr>ily fix$ at #a_/d ( a c>at4 ,) ! *ange to ! metric c>at ! pe>l gra9 0 correspond+ly *ang$ & its weight is n[ #a_/d ( 4#bjj g4 4#je g41 z express$ 9 ! metric sy/em4 ,,lesson ,,xxx ,,t>iff ,,laws ,,on ,,preci\s ,,& ,,imitation ,,/ones ,s9ce x is necess>y = a nation1 z well z = an individual1 to h an income1 & s9ce articles ( luxury are m easily tax$ ?an are ^? ( necessity1 ! traffic 9 gems & _! imitations has frequ5tly be5 made a s\rce ( rev5ue to our gov]nm5t4 ,usually ! p] c5t4 *>g$ z t>iff has be5 comp>atively l[1 especially ^u v valuable gems1 su* z diamonds & pe>ls1 = ! reason t too high a t>iff w\ld t5d to tempt unscrupul\s deal]s to smuggle su* goods into ! c\ntry )\t decl>+ !m4 ,:5 ! m>g9 ( diff]5ce betwe5 ! values1 ) & )\t ! t>iff1 is kept small ! temptation is b slight1 :5 ! dang] ( detection & ! dra/ic nature ( ! usual puni%m5t are tak5 into acc\nt4 ,r\gh /ones h frequ5tly be5 all[$ to ent] ! c\ntry duty free because !y 7 reg>d$ z desirable raw mat]ials :i* w\ld af=d employm5t to home indu/ry4 ,! t>iff laws ( ,octob] #c1 #aiac1 made1 h[ev]1 "s sweep+ *anges 9 ! policy ( our gov]nm5t t[>d preci\s /ones & z ^? laws are /ill 9 =ce 7,april #d1 #aiag7 ?is lesson w attempt to set =? cle>ly ! exact conditions "u ! pres5t law4 ,p]haps ! p>agraph ( fir/ importance to ! trade is ,no4 #ceg :i* reads z foll[s4 #ceg4 ,diamonds & o!r preci\s /ones1 r\gh or uncut1 & n advanc$ 9 condition or value f _! natural /ate by cleav+1 splitt+1 cutt+1 or o!r process1 :e!r 9 _! natural =m or brok51 & bort2 any ( ! =ego+ n set1 & diamond du/1 #aj p] c5tum ad valorem2 pe>ls & p>ts !re(1 drill$ or undrill$1 b n set or /rung2 diamonds1 coral1 rubies1 cameos1 & o!r preci\s /ones & semi-preci\s /ones1 cut b n set1 & suitable = use 9 ! manufacture ( jewelry1 #bj p] c5tum ad valorem2 imitation preci\s /ones1 includ+ pe>ls & p>ts !re(1 = use 9 ! manufacture ( jewelry1 d\blets1 artificial1 or s-call$ syn!tic or recon/ruct$1 pe>ls & p>ts !re(1 rubies1 or o!r preci\s /ones1 #bj p] c5tum ad valorem4 ,x w be notic$ t ! *ief *anges ov] ! previ\s law are fir/ t :i* imposes a #aj duty on r\gh preci\s /ones1 :i* 7 =m]ly free ( duty1 & second ! advance 9 ! duty on cut diamonds & o!r cut /ones f ! =m] #aj to ! pres5t #bj4 ,?is increase 9 ! t>iff 0 reg>d$ z unwise by _m cons]vative import]s1 z ! temptation to defraud ! gov]nm5t is made mu* great] ?an be=e4 ,! *ange 0 ev5 fe>$ by hone/ deal]s :o 7 afraid t !y c\ld n successfully compete ) di%one/ import]s :o might smuggle gems into ! c\ntry4 ,9 spite ( a r det]m9$ opposition ! *ange 0 made & our mo/ repres5tative deal]s h be5 mak+ ! be/ ( ! situation & h be5 do+ all t !y c\ld to help prev5t smuggl+ or at lea/ r$uce x to a m9imum4 ,?r\gh _! k ( ! movem5ts ( diamond /ocks & ( prices !y are able to detect any unduly l>ge supply or any unw>rant$ l[ness ( price & ?us to assi/ ! gov]nm5t ag5ts by direct+ inve/igation t[>ds any deal] :o seems to be enjoy+ immunity f ! t>iff4 ,! "q ( ! /atus ( ,japanese cultur$ pe>ls has be5 settl$ z foll[s4 ,p>agraph #ceg 7quot$ above7 is rul$ to cov] !m & !y are ?us subject to a #bj ad valorem tax4 ,c>bonadoes--m9]s' diamonds--are free ( duty1 "u p>agraph #dgd4 ,crude m9]als are also free ( duty1 p>agraph #edi4 ,p>agraph #fjg decl>es ,specim5s ( natural hi/ory & m9]alogy are free4 ,9 case ! own] is n prep>$ to pay ! tax on import$ m]*&ise ! gov]nm5t holds ! goods = a p]iod ( ?ree ye>s p5d+ su* paym5ts4 ,9 case an import] %[s t import$ m]*&ise 0 pur*as$ at m ?an actual m>ket value1 he may d$uct ! diff]5ce at "t ( entry & pay duty only on ! :olesale =eign m>ket value1 "u ,section ,,iii41 p>agraph #a4 ,on ! o!r h&1 if ! exam9] f9ds m]*&ise to be und]valu$ on ! invoice1 su* m]*&ise is subject to additional p5al duties1 b 9 case ( disagreem5t betwe5 ! import] & ! exam9] z to ! actual m>ket value1 appeal may be tak5 to ! ,cu/oms ,c\rt4 ,s9ce ! ,philipp9e ,isl&s are possessions ( ! ,unit$ ,/ates1 pe>ls f ^? isl&s may be admitt$ free ( duty :5 ! facts ( _! orig9 are c]tifi$ to4 ,9 ! case ( preci\s /ones :i* _h _! orig9 9 ! ,unit$ ,/ates1 b :i* 7 export$ & kept = a "t abroad x has be5 rul$ t su* /ones may be import$ into ! ,unit$ ,/ates free ( duty4 ,:5 preci\s or imitation preci\s /ones are import$ into ! ,unit$ ,/ates & subsequ5tly m\nt$ into jewelry :i* is !n export$1 ! duty :i* 0 paid ^u entry may be refund$ less a d$uction ( #a4 ,! au?or wi%es to ext5d 8 ?anks to ,exam9] ,w4 ,b4 ,treadwell ( ,new ,york1 = 8 assi/ance 9 reg>d to ! subject dealt ) 9 ?is lesson4 ,,bibliography ,! /ud5t ( gems w1 ( c\rse1 want to read _m books on ! subject & ! foll[+ brief bibliography w enable ! beg9n] to select 8 read+ wisely f ! />t4 ,mu* m complete bibliographies w be f\nd 9 "s ( ! books li/$ "h1 "o :i* is notably complete to date ( publication is conta9$ 9 ,diamonds & ,preci\s ,/ones1 by ,h>ry ,emanuel1 ,f4,r4,g4,s41 ,london1 ,john ,camd5 ,hott51 #ahfg4 ,?is cov]s _m languages4 ,! book :i* w probably be f\nd mo/ useful by ^? :o h ma/]$ ?is little text is ! "w by ,g4 ,f4 ,h]b]t-,smi?1 to :i* frequ5t ref]5ce has be5 made at ! close ( _m ( our *apt]s4 ,x is ?or\ghly sci5tific1 yet und]/&able1 & is v complete on ! sci5tific side ( ! subject4 ,gem-,/ones1 ,g4 ,f4 ,h]b]t-,smi?1 ,jas4 ,pott ,co41 ,n4 ,y4 ,= ano!r "w & "o :i* conta9s in=mation ( trade "* z well z sci5tific in=mation ab\t gems see ,preci\s ,/ones by ,w4 ,r4 ,cattelle1 ,j4 ,b4 ,lipp9cott ,co41 ,phila41 or see ,a ,h&book ( ,preci\s ,/ones1 by ,m4 ,d4 ,ro?s*ild1 ,g4 ,p4 ,putnam's ,sons1 ,n4 ,y4 ,gems & ,gem ,m9]als1 by ,oliv] ,cumm+s ,f>r+ton1 ,a4 ,w4 ,mum=d1 publi%]1 ,*icago1 #aijc1 is ano!r good g5]al "w on gems4 ,its color plates ( r\gh gem m9]als are especially good4 ,^? :o are especially int]e/$ 9 ! diamond %\ld see ,! ,diamond by ,w4 ,r4 ,cattelle1 ,! ,john ,lane ,co41 ,n4 ,y41 :i* gives a good acc\nt ( its subject & is ri* 9 comm]cial in=mation1 or ,diamonds3 ,a ,/udy ( ! ,factors :i* ,gov]n _! ,value1 by ! pres5t au?or1 ,g4 ,p4 ,putnam's ,sons1 ,n4 ,y41 #aiad4 ,sir ,wm4 ,crook's1 ! ,diamond1 ,h>p] ,bros41 ,n4 ,y41 is v int]e/+1 especially 9 its acc\nt ( ! au?or's visits to ! ,s4 ,african m9es4 ,/ud5ts ( pe>ls w f9d ,! ,book ( ! ,pe>l1 by ,dr4 ,geo4 ,f4 ,kunz & ,dr4 ,*as4 ,/ev5son1 ,c5tury ,co41 ,n4 ,y41 v complete4 ,a small] "w1 yet a good "o1 on pe>ls is ,! ,pe>l by ,w4 ,r4 ,cattelle1 ,j4 ,b4 ,lipp9cott ,co41 ,phila41 #aijg4 ,?is book is /rong on ! comm]cial side4 ,an old] "w is ,pe>ls & ,pe>l+ by ,d4 ,edw9 ,/reet]1 ,geo4 ,bell ,co41 ,london4 ,a "w on gems & gem-cutt+ by a practical cutt] is ,! ,gem ,cutt]'s ,craft1 by ,leopold ,cl>emont1 ,geo4 ,bell ,sons1 ,london1 b x %\ld be said t v few trade secrets w be f\nd expos$ 9 ! book4 ,on ! subject ( sci5tific preci\s /ones ,! ,production & ,id5tification ( ,artificial ,preci\s ,/ones1 by ,noel ,heaton1 ,b4,sc41 ,f4,c4,s41 read be=e ! ,royal ,society ( ,arts1 ,apr4 #bf1 #aiaa1 is v f9e4 ,x may be _h 9 ! annual ,report ( ! ,smi?sonian ,in/itution = #aiaa1 p4 #bag4 ,x gives "o ( ! be/ acc\nts to be _h ( ! hi/ory ( ! artificial production ( preci\s /ones1 especially ( ! corundum gems4 ,x also conta9s a spl5did acc\nt ( h[ to di/+ui% sci5tific f natural gems4 ,mo/ /ud5ts ( gems w ne$ to ref] frequ5tly to "s good text-book ( m9]alogy4 ,al?\gh old1 ,dana's ,m9]alogy is /ill a /&>d "w4 ,a new] book & "o ( a m popul> nature is ,l4 ,p4 ,gratacap's ,! ,popul> ,guide to ,m9]als1 ,d4 ,van ,no/r& ,co41 ,n4 ,y4 ,among l>g] & m exp5sive books on gems may be m5tion$ ,preci\s ,/ones1 by ,dr4 ,max ,bau]4 ,?is is an ,engli% translation ( a ,g]man "w :i* is a classic 9 its field4 ,z x is n[ out ( pr9t 9 its ,engli% edition1 a some:at detail$ acc\nt ( its "* may be ( value to ^? :o may be incl9$ to g to ! ef=t to seek a copy at a public libr>y or p]haps to pur*ase "o ?r\gh second-h& book /ores4 ,a popul> acc\nt ( _! *>act]s1 occurr5ce & applications1 ) an introduction to _! det]m9ation1 = m9]alogi/s1 lapid>ies1 jewel]s1 etc41 ) an app5dix on pe>ls & coral1 by ,dr4 ,max ,bau]1 ,privy ,c\ncillor1 pr(essor 9 ! ,union ( ,m>burg4 ,translat$ f ! ,g]man by ,l4 ,j4 ,sp5c]1 ,m4,a4 7,cantab471 ,f4,g4,s41 assi/ant 9 ! m9]al dep>tm5t ( ! ,briti% ,museum4 ,) tw5ty plates & n9ety-f\r figures 9 ! text4 ,london1 ,*as4 ,griff9 ,co41 ,ltd43 ,phila41 ,j4 ,b4 ,lipp9cott ,co41 #aijd4 ,! book is a l>ge "o1 xv #fbg pages1 & is divid$ into ?ree p>ts ) an app5dix on pe>ls & coral4 ,"p ,i4 deals ) ! g5]al *>act]s ( preci\s /ones4 #a4 ,natural *>act]s & occurr5ce4 #b4 ,applications ( ,preci\s ,/ones4 #c4 ,classification ( ,preci\s ,/ones4 #ajf pages4 ,"p ,,ii4 ,sy/ematic ,description ( ,preci\s ,/ones1 ,diamond1 ,corundum ,gems1 ,sp9el1 etc4 #dej pages4 ,"p ,,iii4 ,det]m9ation & ,di/+ui%+ ( ,preci\s ,/ones4 #bj pages4 ,app5dix1 #bf pages4 ,pe>ls & ,coral4 ,bau] is exhau/ive 9 8 descriptions ( ! m important preci\s /ones & he also describes briefly v _m little kn[n & little us$ gem m9]als4 ,on =ms ( cutt+ he is old-fa%ion$4 ,fir/ #fh pages giv5 to explanation ( *>act]s us$ 9 id5tify+ /ones4 ,good4 ,on ! ,process ( ,cutt+4 ,pages #gi-hg4 ,good acc\nt4 ,m practical ?an mo/ books give4 ,c>eful acc\nts ( occurr5ce ( preci\s /ones ) maps4 ,"* ( ! occurr5ce ( diamond 9 ,india1 ,brazil1 & ,africa1 q 9 detail4 ,! /ud5t :o wi%es to ma/] ! subject ( gems _c af=d to neglect ,bau]4 ,= ^? :o read ,fr5*1 ! late/1 ! mo/ complete & ?or\gh book on gems is ,jean ,esc>d's ,les ,pi]res ,prcieuses1 ,h4 ,dunod et ,e4 ,p9at1 ,p>is1 #aiad4 ,x is a l>ge & f9ely illu/rat$ "w4 ,! au?or has really outdone ,bau]4 ,! detail 9 reg>d to diamonds especially is v f9e4 ,ev5 ! use ( diamonds 9 me*anical ways is v completely gone into & also details 9 reg>d to cutt+ diamonds are v completely giv54 ,x is to be hop$ t an ,engli% translation w soon become available4 ,ano!r l>ge & ?or\ghgo+ "w is ,g>dn] ,f4 ,williams' ,! ,diamond ,m9es ( ,s\? ,africa1 ,mac,millan1 ,n4 ,y4 ,dr4 ,geo4 ,f4 ,kunz's ,gems & ,preci\s ,/ones ( ,nor? ,am]ica1 ,! ,sci4 ,pub4 ,co41 ,n4 ,y41 #ahij1 #ccf pages1 #h color$ plates 7excell5t ones too71 _m engrav+s1 is a v complete acc\nt ( all publi%$ f9ds ( preci\s /ones 9 ! ,unit$ ,/ates1 ,canada1 & ,mexico1 giv+ a popul> description ( _! value1 hi/ory1 ar*eology1 & ( ! collections 9 :i* !y exi/1 also a *apt] on pe>ls & on rem>kable =eign gems own$ 9 ! ,unit$ ,/ates4 ,_m r>e & little kn[n semi-preci\s /ones are describ$ "h4 ,dr4 ,kunz is also ! au?or ( sev]al m rec5t gem books notably ,! ,magic ( ,jewels & ,*>ms & ,! ,curi\s ,lore ( ,preci\s ,/ones1 ,lipp9cott1 ,phila4 ,among books on engrav$ gems is ! old ,h& ,book ( ,gem ,engrav+ by ,c4 ,w4 ,k+2 ,bell ,daldy1 ,london1 #ahff1 & "o by ,duffield ,osborne2 ,h5ry ,holt ,co41 ,n4 ,y4 ,ano!r book on ?is subject is ,engrav$ ,gems by ,maxwell ,som]ville2 ,drexel ,biddle1 ,phila4 ,= ^? :o wi% /ill fur!r ref]5ces ! foll[+ old] works w prove int]e/+4 ,preci\s ,/ones1 by ,w4 ,r4 ,cattelle2 ,lipp9cott1 ,phila4 ,preci\s ,/ones1 by ,w4 ,good*ild2 ,d4 ,van ,no/r& ,co41 ,n4 ,y4 ,julius ,wodiska1 ( ,new ,york1 has also writt5 an int]e/+ "w on preci\s /ones1 ,a ,book ( ,preci\s ,/ones1 ,putnam's1 #aijg4 ,/ill old] works are ,preci\s ,/ones & ,gems by ,edw9 ,w4 ,/reet]2 ,*apman ,hall1 ,london1 #ahgg4 ,?is is a book ( #bfd pages ) n9e illu/rations4 ,x conta9s mu* ( value & 0 unsurpass$ 9 its day4 ,its fir/-h& acc\nts ( num]\s important1 ev5 celebrat$ diamonds & o!r preci\s /ones w always make x valuable to ! /ud5t ( gems4 ,ano!r book by ! same au?or is ,! ,great ,diamonds ( ! ,_w2 ,geo4 ,bell ,sons1 ,london1 #ahhb2 #cba pages4 ,n illu/rat$4 ,its title adequately describes its cont5ts4 ,x is an excell5t "w4 ,! au?or ev5 travel$ 9 ,india trac+ ! hi/ory ( "s ( ! fam\s diamonds t he describes4 ,diamonds & ,preci\s ,/ones1 by ,l\is ,dieulafait publi%$ 9 its ,engli% translation by ,scribn]1 ,arm/rong ,co41 ,n4 ,y41 #ahgd1 is ano!r old b int]e/+ "w4 ,x has #bib pages & #abf engrav+s on wood4 ,x gives a f9e acc\nt ( diamond cutt+ z practic$ at t "t4 ,!re is also an excell5t hi/ory ( ! production ( artificial preci\s /ones to t date4 ,! ,natural ,hi/ory ( ,preci\s ,/ones & ( ! ,preci\s ,metals by ,c4 ,w4 ,k+1 ,m4,a41 ,bell ,daldy1 ,london1 #ahgj1 is ri* 9 ref]5ces to classical lit]ature4 ,"o or two int]e/+ monographs on preci\s /ones h be5 writt5 & ,! ,t\rmal9e1 by ,augu/us ,c4 ,haml9 is "o ( ^!4 ,mr4 ,haml9 became int]e/$ 9 gems because ( 8 accid5tal discov]y ( "s ( ! f9e t\rmal9es ( ,ma9e4 ,8 ,leisure ,h\rs among ! ,gems is also v readable4 ,jas4 ,r4 ,osgood ,co41 ,bo/on1 #ahhd4 ,x deals especially ) diamond1 em]ald1 opal1 & sapphire4 ,he gives a good acc\nt ( ,am]ican f9ds ( diamond1 & a long acc\nt ( ,european regalia4 ,! book is full ( int]e/+ comm5t & conta9s _m ref]5ces to old] au?ors4 ,! ,te>s ( ! ,heliades or ,amb] z a ,gem1 by ,w4 ,arnold ,buffum1 ,g4 ,p4 ,putnam's ,sons1 ,n4 ,y41 #aijj1 is z its "n implies a monograph on amb]4 ,a good "w on ! hi/ory ( preci\s /ones & on hi/orical-jewels is ,gems & ,jewels by ,madame de ,b>r]a2 ,ri*>d ,b5tley1 ,london1 #ahfj4 ,x deals also ) ! geography ( gem s\rces4 ,an int]e/+ *apt] on ,great ,jewel ,robb]ies is also includ$4 ,( /ill great] age b ( great int]e/ is ,john ,mawe's old "w1 on diamonds & preci\s /ones4 ,9 x ! au?or discusses 9 a conv]sational /yle t is v attractive mu* ( ! gem lore ( 8 day & %[s a pr(\nd k ( 8 subject1 a k t 0 evid5tly fir/ h& & practical1 ,a ,treatise on ,diamonds & ,preci\s ,/ones1 by ,john ,mawe1 ,london4 #bnd edition4 ,pr9t$ = & sold by ! au?or4 ,= read]s ( ,fr5*1 ,jean ,bapti/e ,tav]ni]'s ,voyages1 9 six volumes1 w be va/ly int]e/+4 ,tav]ni] made six j\rneys to ,india & ! ,ea/ betwe5 #afdj & #afhj z a gem m]*ant dur+ :i* "t he pur*as$ & br\ght back to ,europe _m celebrat$ gems includ+ ! fam\s ,fr5* blue diamond :i* he sold to ,l\is ,,xiv4 & :i* 0 /ol5 at ! robb]y ( ! ,g>de ,meuble dur+ ! ,fr5* ,revolution4 ,tav]ni] describes ^! fam\s /ones & _m o!rs t he 0 privileg$ to inspect 9 ! treasuries ( ! ,gr& ,mogul4 ,he also describes int]e/+ly & at great l5g? ! curi\s mann]s & cu/oms ( ! p ( ! ,ea/4 ,les ,six ,voyages de ,jean ,bapti/e ,tav]ni]1 etc41 ,n\velle edition1 ,r\51 #agbd4 ,pl9y's ,natural ,hi/ory1 to g mu* fur!r back1 is full ( ref]5ces to gems1 & gem /ud5ts %\ld run ?r\gh x 7x is to be _h 9 ,engli% translation7 = su* int]e/+ bits z t 9 :i* he describes ! belief t qu>tz cry/al results f ! effect ( v great cold ^u ice1 a belief :i* ,pl9y himself is c>eful n to subscribe to4 ,he cont5ts himself ) relat+ :at o!rs believe 9 ?is reg>d4 ,bo? ! ,hebrew scriptures & ! ,new ,te/am5t af=d _m ref]5ces to gems ) :i* ! eag] /ud5t ( ! subject %\ld be famili>4 ,%e is m preci\s ?an rubies 7ref]r+ to wisdom7 is b "o ( ^!4 ,9 conclusion ! au?or hopes t ?is little text may lead a few to pursue fur!r ?is mo/ fasc9at+ !me & t ! pursuit may br+ mu* ( pleasure z well z ( pr(it4 ,,index ,absorption1 #ae ,adamant9e lu/]1 #dj1 #da ,agate1 #abh1 #ach1 #agb1 #aig ,alex&rite1 #adj ,alm&ite 7see ,g>net7 ,alt]$ /ones1 #bdg-bdi1 #bej-beg ,amazonite1 #agf ,ame?y/1 #id1 #agj1 #aie1 #aif ,aquam>9e1 #adc1 #ahi ,azurite1 #acb1 #adh1 #agg1 #aii ,balances1 ,c>e & use (1 #bhc-bic ,b]yl1 #hd1 #adc1 #aij ,bibliography1 #cja ,blood/one1 #agb ,blue diamonds1 #ia ,blue-:ite diamonds1 #ia ,brazilian diamonds1 #ahb ,brilliancy1 #bjc ,brilliant cut /ones1 #bcc ,brilliant1 ,!ory ( !1 #bje ,brittl5ess ( gems1 #aai ,br[n /ones1 #ie ,bubbles 9 gems1 #ajc ,bubbles 9 glass1 #ha ,bubbles 9 sci5tific /ones1 #ajc ,burmah rubies1 #aed ,cabo*ons1 #de1 #baf1 #bbg ,c>bon1 #acf ,c>borundum1 #ed1 #ee1 #ef ,c>nelian1 #abh1 #ach1 #agb ,cat's-eye1 #dd-df1 #ach1 #aga ,*alc$ony1 #ach ,*rysob]yl1 #de1 #he1 #abb1 #adj1 #aeg1 #ahh ,*rysob]yl cat's-eye1 #de1 #df1 #he1 #ahh ,*rysolite1 #agf ,c9namon /one1 #add ,citr9e qu>tz1 #afa1 #aga1 #aie1 #aif ,cleav+ ( diamonds1 #bjh ,cleav+ ( preci\s /ones1 #bac ,color1 cause (1 9 m9]als1 #ae ,color ( gems1 #ff-ib ,colorless /ones1 #ig ,corundum gems1 #fh-gj1 #gc1 #aja1 #aba1 #acd1 #acg ,corundum gems1 defects (1 #aja ,cultur$ pe>ls1 #bgg-bgi ,cutt+ ( diamonds1 #bji ,cutt+ ( preci\s /ones1 #bja-bbf ,demantoid g>net1 #fb1 #fd1 #hb1 #acj1 #add1 #afi1 #aic ,d5sity ( m9]als1 #bc ,diamonds1 #fa1 #gc1 #ia1 #abj1 #acd1 #aea-aec1 #agi-ahf ,di*roism1 #ae-bb1 #aac ,di*roscope1 !1 #ag-bj ,disp]sion1 #fj-fe ,d\ble refraction1 #e ,d\blets1 #da1 #bda-bdf ,em]ald1 #ge-hb1 #adc1 #afd1 #ahi ,em]ald1 we>+ qualities (1 #aji ,epidote1 #i ,extraord9>y ray1 #af ,fancy diamonds1 #ia1 #aea ,fire1 cause (1 #bjg ,=ms ( preci\s /ones1 #bbg-bcf ,g>net1 #fi1 #hb1 #if1 #acj1 #adc1 #add1 #afg-agj1 #aib-aid ,g>net1 ,alm&ite1 #adc1 #afh1 #aic ,g>net1 ,&radite1 #hb1 #acj1 #add1 #afi1 #aic ,g>net1 ,demantoid1 #fb1 #fd1 #hb1 #acj1 #add1 #afi1 #aic ,g>net1 ,pyrope1 #add1 #afh1 #aib1 #aic ,glass1 #fb1 #adb ,glass imitations1 #ha1 #bcg-bdi ,golcondas1 #ahj ,gra9 base1 price ( pe>ls p]1 #bga ,h>dness1 #dg-ed1 #ee-ei1 #aac ,h>dness & we>+ qualities1 #aai-acb ,h>dness1 ,mohs's scale (1 #dh-ea ,h>dness1 table (1 #ed ,h>dness1 te/ (1 #ea-ed1 #eh ,heliodor1 #afe ,hope ,blue diamond1 #ia ,hyac9?1 #aff ,imitations ( preci\s /ones1 #bcg-bdi ,imitations ( pe>ls1 #bgg-bhb ,imp]fections1 #aaa ,imp]fections 9 corundum gems1 #aja ,imp]fections 9 glass1 #ha ,imp]fections 9 sci5tific /ones1 #ajd ,jac9?1 #aff ,jade1 #abh1 #adg1 #age1 #aig ,jadeite1 #abh1 #aig ,j>goons1 #aff ,jasp]1 #abh1 #agb ,kunzite1 #aie ,lapis lazuli1 #acb1 #agg1 #aii ,labradorite1 #agf ,lu/]1 #ch-db ,make ( diamonds1 #bje-bjg ,make ( preci\s /ones1 #bbj ,mala*ite1 #acb1 #adh1 #agg1 #aii ,metallic oxides1 #acg ,m9]al species1 #acc-adh ,mix$ cut /ones1 #bcf ,mohs's scale ( h>dness1 #dh-ea ,moon/one1 #dd1 #de1 #aca1 #adf1 #agf1 #aih ,morganite1 #afe ,nacre1 #bhj ,nam+ preci\s /ones1 #adi-afc1 #afd-agh ,nephrite1 #abi1 #aig ,occurr5ce ( preci\s /ones1 #agi-bjj ,oliv9e 7see ,demantoid ,g>net7 ,oliv9e1 #hc1 #agf ,onyx1 #agb ,opal1 #dd1 #aca1 #aci1 #agc ,ord9>y ray1 #af ,ori5t ( pe>ls1 #bfa ,ori5tal /ones1 #hd1 #aef ,pa/e gems1 #adb1 #bcg-bda ,pe>ls1 #beh-bgf ,peel+ pe>ls1 #bfe ,p]idot1 #h1 #acj1 #agf1 #aih ,p9k /ones1 #ic ,p9k$ topaz1 #bej ,plasma1 #agb ,poli%+ ( diamonds1 #baj ,poli%+ ( preci\s /ones1 #bah ,prase1 #ach1 #agb ,prop]ties1 def9ition (1 #a ,purple /ones1 #id ,qu>tz1 av5tur9e1 #aga ,qu>tz1 citr9e1 #afa1 #aga1 #aie1 #aif ,qu>tz gems1 #de1 #abg1 #aga1 #aie1 #aig ,reflection1 total1 #bjd ,refraction1 #d ,refraction1 d\ble1 #h-ac ,refraction1 d\ble1 te/ =1 #aj1 #aab ,refractomet]1 #e ,rhodolite g>net1 #afh ,roman pe>ls1 #bgi ,rose cut /ones1 #bca ,rose qu>tz1 #aga1 #aig ,rubellite1 #ic ,ruby1 #ab1 #fg1 #fi1 #aec1 #aed1 #ahf ,ruby1 sci5tific1 #ii-ajh ,sapphires1 #fc1 #hg1 #hh1 #aee1 #ahg ,s>d1 #agb ,s>donyx1 #agb ,sci5tific /ones1 #ii-ajh ,sci5tific /ones1 defects 91 #ajd ,sci5tific /ones1 te/s =1 #ii-ajh ,siam rubies1 #aed ,silicates1 #ada ,silk 9 rubies1 #aag ,slitt+ ( preci\s /ones1 #bac ,s\? ,african diamonds1 #ahd ,specific gravity1 #bc-cg1 #aad ,sph5e1 #i1 #fb1 #fd ,sp9els1 #ga1 #ij1 #abc1 #adj1 #aeh1 #ahh ,spodum5e1 #ie1 #agj1 #aie ,/> /ones1 #dd1 #df1 #aeg ,/ep cut /ones1 #bce ,/ructure ( pe>ls1 #beh ,table1 ( h>dness1 #ed ,table ( refraction1 #ab-ac ,table ( specific gravity1 #bi ,t>iff laws1 #bid-bii ,te/ = d\ble refraction1 #aj ,te/+ h>dness1 #ea-ed1 #eh ,te/+ imitations ( pe>ls1 #bha ,te/+ unkn[n gems1 #aji-aah ,tig]'s-eye1 #de1 #ach1 #aga ,topaz1 #fg1 #gc1 #ia1 #abd1 #ade1 #aei1 #ahi ,t\ghness 9 /ones1 #aai ,t\rmal9e1 #gb1 #gg1 #gi-ha1 #if1 #adf1 #afg1 #aid ,triplets1 #gi1 #bdf ,turquoise1 #acj1 #adh1 #aih ,unit ( weight1 #bhi ,v>iscite1 #adh ,vitre\s lu/]1 #da ,we>+ qualities ( gems1 #aai ,zircon1 #i1 #fb1 #gb1 #ib1 #ig1 #abe1 #adg1 #aff1 #aia ,diamonds ,a ,/udy ( ! ,factors t ,gov]n _! ,value ,by ,frank ,b4 ,wade ,i %all speak a little m ( ! diamonds1 t !y :o "k !m n may n be deceiv$ by *apm5 :o g ?r\gh ! c\ntry sell+ !m1 = :oev] w buy ! diamond1 x is ne$ful t he "k !m1 444--,*ap4 ,,xiv41 ,! ,voyages & ,travels ( ,sir ,john ,maundeville4 ,table ( ,cont5ts ,i4--,col\r4 ,,ii4--,flaws4 ,,iii4--,make4 ,,iv4--,repair+ & ,recutt+4 ,v4--,m\nt+4 ,,vi4--,buy+ ! ,engagem5t ,r+4 99 99 99 99 99 ,g4 ,p4 ,putnam's ,sons ,new ,york ,london ,a ,book ( ,preci\s ,/ones ,! ,id5tification ( ,gems & ,gem ,m9]als & an ,acc\nt ( ,_! ,sci5tific1 ,comm]cial1 ,arti/ic1 & ,hi/orical ,aspects ,by ,julius ,wodiska #hvo4 ,) #cc ,full-page ,illu/rations & #d ,color$ ,plates ,a description1 9 altoge!r a new fa%ion1 ( gems & gem m9]als1 _! nature & hi/ory1 compreh5sible to e read]1 & ( prime value to /ud5ts & to jewel]s4 ,! g5]al read] w enjoy ! simple descriptions ( ! orig91 developm5t1 & treatm5t ( ! diamond1 sapphire1 & o!r preci\s /ones1 z well z ( ! beautiful semi-preci\s /ones4 ,j en\gh ( ! te*nical has be5 provid$ to make ! new gem book a vade mecum = /ud5ts ( gem m9]als & = ! army ( jewel]s 9 ! ,unit$ ,/ates1 z well z _! fell[-craftsm5 & m]*ants 9 all ,engli%-speak+ places4 ,! art & indu/ry ( m\nt+ gems is some:at elaborately cov]$1 especially z exemplifi$ 9 ! "w ( /ud5ts at te*nical s*ools & ! _m unatta*$ work]s 9 jewelry design+ & mak+ :o =m a "p ( ! ,arts & ,crafts movem5t4 ,"s ( ! qua9t sup]/itions ab\t gems 9 ! *apt] on folklore h a curi\s int]e/4 ,! au?or takes cognizance ( ! public desire n[adays = ! novel & uncommon 9 gems1 & %[s t prospectors1 gem m9]s1 m9]alogi/s1 & jewel]s are co-op]at+ to greatly l5g!n ! li/s ( popul> semi-preci\s /ones4 ,a *apt] is devot$ to collections ( gems 9 museums4 99 99 99 99 99 ,g4 ,p4 ,putnam's ,sons ,new ,york ,london 99 99 99 99 99 ,transcrib]'s ,note3 ,inconsi/5t hyph5ation & spell+s h be5 /&>dis$1 al?\gh consi/5t v>iants rema9 z pr9t$4 ,m9or typographical errors h be5 correct$ )\t note1 :il/ significant *anges are li/$ bel[4 p4 #ac1 'ind5tity' am5d$ to id5tity3 '444 ( unkn[n id5tity comes along 444'2 p4 #bj1 'dis*roism' am5d$ to di*roism3 '444 b %[s h>dly any di*roism4'2 p4 #fg1 'qu>t' am5d$ to qu>tz3 '444 7qu>tz topaz7 444'2 p4 #aah1 ',saphire d'eau' am5d$ to ,saphir d'eau2 pp4 #adj1 #adc1 'b]ylium' am5d$ to b]yllium2 pp4 #adh1 #cah1 ',v>icite' am5d$ to ,v>iscite2 p4 #aeg1 ',cs>' am5d$ to ,cz>3 '444 ,cz> ,alex&] ,,ii41 9 ^: 444'2 p4 #afg1 'rubelite' am5d$ to rubellite3 '444 sometimes call$ rubellite1 & :ite 444'2 p4 #aij1 ',m9as ,g>aes' am5d$ to ,m9as ,g]aes2 p4 #aii1 ',khorassan' am5d$ to ,khorasan3 '444 prov9ce ( ,khorasan 9 ,p]sia 444'2 p4 #bbg1 'cabo*' am5d$ to cabo*e2 p4 #beh1 'uniom>g>if]' am5d$ to ,unio m>g>itif]a2 p4 #bih1 'me*&ise' am5d$ to m]*&ise3 '444 tax on import$ m]*&ise 444'2 p4 #cja1 ',emanual' am5d$ to ,emanuel3 '444 ,diamonds & ,preci\s ,/ones1 by ,h>ry ,emanuel 444'2 p4 #cja1 ',hatt5' am5d$ to ,hott53 '444 ,john ,camd5 ,hott5 444'2 p4 #cjh1 ',/reetor' am5d$ to ,/reet]3 ',preci\s ,/ones & ,gems by ,edw9 ,w4 ,/reet] 444'2 p4 #cad1 ',epidot' am5d$ to ,epidote4