GIA COLORED STONES

GIA COLORED STONES


Mineralxc-xcanswer--
Axcnatural,xcinorganicxcsubstancexcwithxcaxccharacteristicxcchemicalxccompositionxcandxcu
suallyxccharacteristicxcstructure.

Mixedxccutxc-xcanswer--Axccuttingxcstylexcthatxccombinesxcbrilliant-
cutxcandxcstepxccutxcfacets.

Abrasionsxc-xcanswer--
Tinyxcnicksxcandxcpitsxccausedxcbyxcwearxcandxcdamagexctoxcaxcgem'sxcfacetxcedgesxcorxccu
let.

Absorptionxcspectrumxc-xcanswer--
Axcpatternxcofxcdarkxcverticalxclinesxcorxcbandsxcshownxcbyxccertainxcgemsxcwhenxcviewedxct
hroughxcaxcspectroscope.

Adularescencexc-xcanswer--
Thexccloudyxcbluishxcwhitexclightxcinxcaxcmoonstone,xccausedxcbyxcscatteringxcofxclight.

Agatexc-xcanswer--
Chalcedonyxcwithxcaxccurvedxcorxcangularxcbandsxcorxclayersxcthatxcdifferxcinxccolorxcandxctr
ansparencyxc.

Aggregatexc-xcanswer--Axcmassxcofxctiny,xcrandomlyxcorientedxccrystals.

Akoyaxc-xcanswer--
CommonxcnamexcforxcthexcPinctadaxcfucataxcoysterxcandxcthexcnaturalxcorxcculturedxcpearl
sxcitxcproduces.

Allochromaticxc-xcanswer--
Axcgemxccoloredxcbyxctracexcelementsxcinxcitsxccrystalxcstructure.

Alluvialxcdepositxc-xcanswer--
Axcdepositxcwherexcgemsxcarexcerodedxcfromxctheirxcsourcexcrock,xcthenxctransportedxcawa
yxcfromxctheirxcsourcexcandxcfurtherxcconcentrated.

Amorphousxc-xcanswer--Lackingxcaxcregularxccrystalxcstructure.

Aragonitexc-xcanswer--Axccrystalizedxcformxcofxccalciumxccarbonatexcfoundxcinxcnacre.

Assembledxcstonexc-xcanswer--
Twoxcorxcmorexcseparatexcpiecesxcofxcmaterialxcjoinedxctoxcformxcaxcunit.

,Asterismxc-xcanswer--
Crossingxcofxcchatoyantxcbands,xccreatingxcaxcstarxcinxcthexcdomexcofxccabochon.

Atomxc-xcanswer--Thexcbasicxcstructuralxcunitxcofxcallxcmatter.

Aventurescencexc-xcanswer--
Axcglitteryxceffectxccausedxcbyxclightxcreflectingxcfromxcsmall,xcflatxcinclusionsxcwithinxcaxcge
mstone.

Backgroundxccolorxc-xcanswer--Anxcopal'sxcbodycolor,xcindependentxcofxcitsxcplay-of-
color.

Beadxcnucleusxc-xcanswer--
Axcbeadxcusedxcasxcthexccorexcofxcaxcculturedxcpearl,xcusuallyxcmadexcfromxcaxcfreshwaterxc
musselxcshell.

Bleachingxc-xcanswer--
Axctreatmentxcthatxcusesxcchemicalsxctoxclightenxcorxcremovexccolor.

Blemishxc-xcanswer--
Characteristicxcorxcirregularityxcconfinedxctoxcthexcsurfacexcofxcaxcpolishedxcgemstone.

BluexcSheenxc-xcanswer--
Tradexctermxcforxcaxchighlyxcprized,xcvividxcbluexcadularescencexcdisplayedxcbyxcthexcfinest
xcmoonstone.



Bodycolorxc-xcanswer--
Axcgemstone'sxcbasicxccolor,xcdeterminedxcbyxcitsxcselectivexcabsorptionxcofxclight.

Botryoidalxc-xcanswer--
Axccrystalxcgrowthxchabitxcwithxcaxcbumpyxcappearancexcsimilarxctoxcaxcbunchxcofxcgrapes.

Boulderxcopalxc-xcanswer--Thinxclayersxcofxcpreciousxcopal,xccutxctoxcincludexcmatrix.

Boulexc-xcanswer--Axccylindricalxcsyntheticxccrystalxcproducedxcbyxcthexcflame-
fusionxcprocess.

Brilliancexc-xcanswer--
Lightxcthatxceventuallyxcreturnsxctoxcthexceyexcafterxcenteringxcaxcgemxcthroughxcthexccrown
,xcreflectingxcoffxcitsxcpavilionxcfacets,xcandxcexitingxcbackxcthroughxcthexccrown.

Brilliantxccutxc-xcanswer--Cuttingxcstylexcwithxctriangularxcorxckite-
shapedxcfacetsxcthatxcradiatexcfromxcthexccenterxctowardxcgirdle.

Cabochonxc-xcanswer--
Axcsmoothlyxcroundedxcpolishedxcgemxcwithxcaxcdomedxctopxcandxcaxcflatxcorxccurvedxcbase
.

Calcareousxcconcretionxc-xcanswer--Axcnon-nacreousxcnaturalxc"pearl".

,Calibratedxcsizesxc-xcanswer--Gemstonexcsizesxccutxctoxcfitxcstandardxcmountings.

Cameoxc-xcanswer--
Axcgemxccarvingxcstylexcinxcwhichxcthexcdesignxcoftenxcaxcwomen'sxcprofile,xcprojectsxcsligh
tlyxcfromxcaxcflatxcorxccurvedxcsurface.

Cavityxc-xcanswer--Anxcopeningxcthatxcextendsxcintoxcaxcgemxcfromxcthexcsurface.

Centipedesxc-xcanswer--
Tinyxctensionxccracksxcinxcaxcmoonstonexcthatxcinterferexcwithxcadularescencexcandxcreduc
excvalue.

Ceramicxcprocessxc-xcanswer--
Axcprocessxcinxcwhichxcgroundxcpowderxcisxcheated,xcsometimesxcunderxcpressure,xctoxcpr
oducexcaxcfine-grainedxcsolidxcmaterial.

Certificatexcofxcoriginxc-xcanswer--
Axcdocumentxcthatxcindicatesxcaxcstone'sxcgeographicxcorigin,xcbasedxconxcitsxcinclusionsxc
andxctracexcelementxcchemistry.

Chalcedonyxc-xcanswer--Axccryptocrystallinexcquartzxcaggregate.

Chargexctransferxc-xcanswer--
Axcprocessxcwherexcthexcelectronsxcthatxcselectivelyxcabsorbxclightxcarexcpassedxcbackxcan
dxcforthxcbetweenxcneighboringxcimpurityxcions.

Chatoyancyxc-xcanswer--
Bandsxcofxclightxcinxccertainxcgems,xccausedxcbyxcreflectionxcofxclightxcfromxcmanyxcparallel,
xcneedle-likexcinclusionsxcorxchollowxctubes.



Chemicalxccompositionxc-xcanswer--
Kindsxcandxcrelativexcquantitiesxcofxcatomsxcthatxcmakexcupxcaxcmaterial.

Chemicalxcelementxc-xcanswer--
Axcsubstancexcthatxcconsistsxcofxcatomsxcofxconlyxconexckind.

Chipxc-xcanswer--Axcdamagedxcareaxconxcaxcgem,xcusuallyxcnearxcthexcgirdle.

Chromexctourmalinexc-xcanswer--
Tradexctermxcforxcaxcvibrantxcgreenxctourmalinexcthat'sxccoloredxcbyxctracesxcofxcvanadium,
xcchromium,xcorxcboth.



Circledxcpearlxc-xcanswer--
Axcpearlxcwithxconexcorxcmorexcgroovedxcorxcridgedxcringsxcallxcthexcwayxcaroundxcit.

Cleavagexc-xcanswer--
Axcsmooth,xcflatxcbreakxcinxcaxcgemstonexcparallelxctoxcplanesxcofxcatomicxcweakness,xccau
sedxcbyxcweakxcorxcfewerxcbondsxcbetweenxcatomsxcorxcboth.

, Cloudxc-xcanswer--
Anyxchazyxcorxcmilkyxcareaxcthatxccannotxcbexcdescribedxcasxcaxcfeather,xcfingerprint,xcorxcg
roupxcofxcincludedxccrystalsxcorxcneedles.

Cobbingxc-xcanswer--
Removingxcheavilyxcincludedxcsectionsxcfromxcaxcgemstonexcroughxcbyxccarefullyxctapping
xcitxcwithxcaxcsmallxchammer.



Colorxccenterxc-xcanswer--
Axcsmallxcdefectxcinxcthexcatomicxcstructurexcofxcaxcmaterialxcthatxcabsorbxclightxcandxcgivexcr
isexctoxcaxccolor.

ColorxcChangexc-xcanswer--
Axcdistinctxcchangexcinxcgemxccolorxcunderxcdifferentxctypesxcofxclighting.

Colorxcrangexc-xcanswer--Thexcselectionxcofxccolorsxcinxcwhichxcaxcgemstonexcoccurs.

Colorxczoningxc-xcanswer--
Areasxcofxcdifferentxccolorxcinxcaxcgem,xccausedxcbyxcvariationsxcinxcgrowthxcconditions.

Colorlessxcimpregnationxc-xcanswer--
Fillingxcofxcporesxcorxcotherxcopeningsxcwithxcmeltedxcwax,xcresin,xcpolymer,xcorxcplasticxcto
xcimprovexcappearancexcandxcstability.



Commercialxcmarketxc-xcanswer--Marketxcsectorxcwherexcaverage-
qualityxcgemstonesxcarexcusedxcinxcmass-marketxcjewelry.

Conchiolinxc-xcanswer--
Thexcorganicxc"glue"xcinxcnacrexcthatxcholdsxcaragonitexcplateletsxctogether.

Conchoidalxcfracturexc-xcanswer--
Axccurvedxcandxcridgedxcfracturexcinxcaxcgemstone,xcextendingxcfromxcthexcsurfacexcinward
.

Consignmentxc-xcanswer--
Axcselectionxcofxcgoodsxcloanedxctoxcaxcdealerxcbyxcanotherxcwholesalerxcorxcgemxccutter.

Contactxcmetamorphismxc-xcanswer--
Localizedxcchangesxccausedxcbyxcanxcigneousxcintrusionxcthatxctakesxcplacexcwherexcthexc
magmaxcmeetsxcthexcsurroundingxcrock.xcNewxcmineralsxcmayxcformxcduexctoxctemperatur
excchangesxcorxcintroductionxcofxcfluidsxcfromxcthexcmagma.

Corexc-xcanswer--Thexcearth'sxcinnermostxclayer.

Crazingxc-xcanswer--
Thexcnetworkxcofxctinyxcfracturesxcthatxcdevelopxcwhenxcopalxclosesxcmoisture.

Crownxc-xcanswer--Topxcpartxcofxcthexcgemxcabovexcthexcgirdle.