beryllium diffused blue sapphires at june 26th 2009
DESCRIPTION
sapphire inclusionTRANSCRIPT
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BerylliumTreatedBlueSapphires
Continuingmarketobservationsandupdateincludingtheemergenceoflargersizestones
GarryDuToit,JitlapitThanachakaphadandKennethScarratt
GIALaboratory,Bangkok
June25th2009
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Figure1:Abluesapphirerecentlyexaminedinthelaboratoryweighing22.52ctwasdeterminedtocontain7.509.50ppmaofberylliumbyusingLAICPMS.Photo:SuchadaKittayachaiwattanaGIA
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Abstract
Thispaper,whichconstitutesasmallportionofanongoingproject,isanupdateonthepresenceinthe market of beryllium treated blue sapphires, the types of material and their identifyingcharacteristics.Fivecommercialquality (in the1ct range)beryllium treatedbluesapphires thatarerepresentativeofalargeparcelrecentlypurchasedontheBangkokmarketaredescribedwithdetailsof their chemistry, inclusion scenes and optical data. Further, two large 22ct and 53ct berylliumtreatedbluesapphires thatare reportedly treatedbyadifferent techniquearealsodescribed.Thedatarevealsseveraltypesofstartmaterialareusedfortheberylliumtreatmentofbluesapphiresbutthat in each case there are important clues that lead the gemologist toward the nature of thetreatmentwiththeultimatetestbeinganalysisusingLAICPMS.
Acknowledgements
Theauthorsacknowledgewith thanks thecontinuedassistancebeinggiven to themas thisprojectprogressesbyJohnEmmett,TerryColdhamandThawatchaiSomjaineuk.
Introduction
In 2003 (Emmett, et al., 2003) Emmett discussed (From our analysis of the impact of berylliumdiffusiononverydarkbluesapphireswhere[Ti4+]>>[Mg2+],wefindthatberylliumdiffusionshouldproducethecondition[Ti4+]>[Mg2++Be2+],substantiallyreducingthebluecolorsaturation)andshowedhowoverdarkbluesapphirescouldbelightenedtoamorecommercialblue.Itisalsoworthyof note that Emmett (Emmett, 2007) in a memo to the corundum group (a small group ofgemologicallyminded individualswitha strong interest in thechemistryandphysicsofcorundum)and following further research, states that the beryllium ppm range required for visible coloralterationinbluesapphireisaslittleasbetween0.5and1.5ppma(1ppma=0.45ppmw).
InJuly2003andagaininJuly2004GemmologicalAssociationofAllJapanreportedtomembersoftheLaboratoryManualHarmonizationCommitteethattheyseemedtobedetectingconcentrationsofBeinsomeheatedbluesapphires(Figure15).Inoneinstancein2004theyreportedtheamounttobe10to35ppmw.However,itwasnotclearatthetimeifthesewereintentionallytreatedalongthelinesof the Emmett explanation (above) or by some other process, or that they were some of thesapphiresthathadnotturnedyellow(butneverthelesswerediffusedwithBe)duringtheberylliumtreatment processes used to create the yellow and padparadscha colors that were the focus oftreatersduringthatperiod( ).TheGAAJwerealsoatthistimeusingtheirnewlyacquiredLAICPMS which began an era of easier detection of Be and other light elements by gemologicallaboratories.
Figure2
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure2:Anassortmentofcorundumfollowingheatingwithberyllium,notethatwhilemanynowappearellowoforange,manyremainblue.Photo:JohnEmmetty from(Emmett,etal.,2003).
In 2005 while routinely examining stones for Be content Peretti (Peretti, 2005a, Peretti, 2005b)discoveredthatthisorasimilartreatmenttechniquehadbeguntobeusedtocommerciallyenhancethe appearance of blue sapphires. Over the ensuingmonths several authors examined these Betreatedbluesapphiresandreportedtheirobservations(DuToit,2006,Pardieu,2006,Pardieu,2008).
WhiletheconsensusconcerningthesestonesisthatanalyticaldataacquiredbyLAICPMSisrequiredto identify thepresenceofberyllium inanartificiallydiffused form (berylliummayalsobepresentnaturally inblue sapphires (Pardieu,2007, Shen,2007,Pardieu,2008, Shen,2009),whenpresent,certaincharacteristicinclusionsscenesmayindicatethatthistreatmenthadbeenused(Figure3).
FiveBerylliumtreatedbluesapphiresrepresentingalargeparcel
BeinglocatedinBangkoktheauthorsareoftenaskedabouttreatedrubiesandsapphiresandifmanyfindtheirwaytothelaboratory.Inthelast12monthsseveralpeoplehaveaskedifmanyBerylliumtreatedblue sapphiresare submitted forexamination towhichweanswer;no,even thougheveryheated sapphire is checked for Be content very few Be treated stones are discoveredwithin thesamplessubmitted. However,wedoexpandonthisbycautioningthatthetypeofstonesthataresubmittedtolaboratoriesmaynotberepresentativeoftheavailablematerialinthemarket.Indeedafterbeingaskedthisquestionafewtimes,wehavegoneoutintothemarketandfounditrelativelyeasy to obtain large parcels of Be treated blue sapphires (being sold under various name tags)e.g.,Figure4.
RecentlyTerryColdhamofSapphex(Australia)knowinglypurchasedalargeparcelofBetreatedbluesapphiresinBangkok(exampleimageFigure4).UponthestonesreachinghiminAustraliahelookedthroughthe lotonhismicroscopeandsuspectedthattheywerea littledifferentfromthematerialthat had been previously described in the texts. He selected five stones (Table 1) that wererepresentative (Figure 5) and sent them toGIA LaboratoryBangkok for further examination. Thestoneswereallovalfacetedandweighedbetween0.874and1.209ct. Thecolorsvariedfrom light(stone1)todark(stone3)blueincolor.
Table1:FiveberylliumtreatedbluesapphirespurchasedbyTerryColdhamontheBangkokmarketin2009
Sample Ctweight Notes
sapphire1 0.891 Wasovalfaceted;nowpolishedtoanopticallyorientedcube
sapphire2 0.874
sapphire3 1.101
sapphire4 1.209 Wasovalfaceted;nowpolishedtoathinsectionseeFigure5 sapphire5 0.883
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure3:ThewebandspringlikeinclusionsceneoftenrecordedinBerylliumtreatedbluesapphires.PhotoShaneMcClure@GIA
Figure4:AnimageexampleofBetreatedbluesapphirescurrentlyontheBangkokmarket(photoTerryColdham)
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure 5: Five Be treated blue sapphires selected as a representative sample from a larger lot purchased inBangkok inMarch 2009. They are from left to right 1 (0.891ct), 2 (0.874ct), 3 (1.101ct), 4 (1.209ct) and 5(0.883ct).
Berylliumandothertraceelementcontent
Uponreceiptofthefivestones (Figure5)andasthesehadbeensoldasBetreatedbluesapphires,theywerefirstlyanalyzedusingLAICPMS.Threespotswerechosenatrandomonthegirdleofeachstone foranalysisand the resultsare setout inTable1. Allof the stoneswere found to containberyllium,withsomespotsrecordingquitehighlevels.TheBelevelsrecordedrangedfrom11.77to45.15ppma. Otherelement levelswerealsorecordedwithNbandTahavingnoconcentrations (instones that contain beryllium naturally the Be tends to correlatewith the presence of these twoelements (andpotentiallyothers)which isnot the case for artificially treated stones (Shen,2007,Shen,2009).IncomparisonwiththeTicompositionrelativelyhighMgconcentrationswererecordedforthesesampleswhichdoesnotfitwellwiththe[Ti4+]>[Mg2++Be2+]scenarioforlighteningdarkbluesapphiresaspresentedbyEmmett(Emmett,etal.,2003)asoneofthereasonsfortreatingbluesapphiresbythismethod.IndeedthedescriptiongivenoftheprocessamongsttradersinBangkokisthat the stones are darkened by the Be treatment and not lightened; something that is eitherreportedconjectureoraprocesswedonotpresentlyunderstand.
Table 2: The beryllium levels found to be present at three spots for each of the Be treated blue sapphiresdepictedinFigure3,plusthelevelsforTi.V,Cr,FeandGainppma.
Sample Be Mg Ti Cr Fe Ga
sapphire1_sp1 13.43 35.18 30.65 0.00 193.00 16.46sapphire1_sp2 10.83 35.17 29.51 1.47 187.67 16.26sapphire1_sp3 11.77 20.90 16.67 4.81 174.42 15.56
sapphire2_sp1 15.87 44.77 37.21 5.31 573.60 17.57
sapphire2_sp2 16.84 47.23 40.05 4.86 487.44 17.72
sapphire2_sp3 13.69 41.72 41.59 5.74 637.87 18.63
sapphire3_sp1 27.36 22.87 22.65 9.12 722.57 16.30sapphire3_sp2 45.15 25.40 24.54 10.59 725.13 16.29sapphire3_sp3 15.25 28.54 28.35 9.89 733.16 15.74
sapphire4_sp1 14.27 25.95 26.02 5.69 250.91 17.83sapphire4_sp2 14.98 29.98 26.03 5.96 281.73 18.65sapphire4_sp3 15.95 28.48 25.63 5.87 273.44 19.17
sapphire5_sp1 29.45 22.60 27.45 1.10 229.95 12.88sapphire5_sp2 18.79 49.16 51.15 2.57 263.98 14.00sapphire5_sp3 18.80 62.38 69.46 2.83 277.38 14.18
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Depthofslice1.03mmOldweight1.209ctNewweight0.359ct
129
9
41
30
3.34mm
7.24mm
Figure6:Betreatedsapphirenumber4waspolisheddowntoathinsliceandsampledat41pointsbyLAICPMStodeterminethedepthorthebepenetrationalongwithotherelementdistribution.Notethattheablationspottothefarrightwasnotincludedintheanalysis.
Totestthevalidityofthechemicaldataobtainedatthesurfaceofthefacetedstones,andrealizethepenetrationdepthof theBeused in theprocess, stonenumber4,originallyanoval faceted stoneweighing 1.209ct, was ground down and polished to a thin slice without shortening its greatestdimension(Figure6).Theslicewasthencleanedinaquaregia 1inpreparationforchemicalanalysisbyLAICPMS.Theslicewasthenanalyzedat41pointsfromtheedges(girdle,culetandtable)tothedeepestpointswithintheoriginalfacedstone(29pointsparalleltotheoriginalgirdleand12pointsfromtheoriginaltabletoculet).
TheresultsoftheanalysesfortheelementsBe,Mg,Ti,Cr,FeandGaarepresentedinTable3.TheseresultsshowarelativelyevendistributionofMg,Ti,Cr,FeandGa (Figure7) foreachofthepointsanalyzedbutforBetheretendstobe largerconcentrationtowardstheedgeswhencomparedwiththecenterofthestoneexamined(Figure8andFigure9).ThistendencyofalowerBeconcentrationtowards the center is to be expected for a situationwhere the elementhas been diffused into afacetedorpreformedstone.
1Aquaregiaisa1:3mixtureofnitricandhydrochloricacidsusedtocleananypolishingresiduesthatmightinterferewithachemicalanalysis.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Table3:Theconcentrations(inppma)forBe,Mg,Ti,FeandGatakengirdletogirdleandtabletoculetrecordedforsapphire#4afterbeingpolisheddowntoathinslice(Figure6)fromtheoriginalovalfacetedform(Figure5).
Spot Be Mg Ti Cr Fe Ga
1 12.71 27.04 23.80 7.29 471.71 18.47
2 12.32 28.35 21.49 9.85 465.14 18.80
3 10.96 29.13 23.81 11.08 487.04 19.97
4 9.86 30.50 22.59 11.81 465.50 19.12
5 10.12 29.59 22.90 12.35 470.98 18.85
6 11.04 29.32 26.11 11.54 479.38 18.99
7 9.26 29.67 23.69 9.59 473.53 17.66
8 9.35 32.91 25.34 10.71 468.42 18.14
9 9.36 27.98 25.60 11.47 467.69 18.85
10 6.74 26.51 24.01 11.60 464.77 19.19
11 8.44 31.86 22.90 10.97 457.47 18.66
12 8.80 33.68 24.23 12.10 481.20 18.85
13 8.55 27.89 25.68 9.36 469.15 19.07
14 6.94 30.88 23.93 11.71 474.63 18.39
15 7.46 31.63 24.98 11.53 476.09 18.26
16 6.85 31.68 22.24 11.56 468.42 18.38
17 6.63 30.31 24.18 10.62 483.39 18.64
18 7.19 31.21 23.59 11.64 470.61 18.85
19 7.48 31.56 22.82 11.05 461.85 18.51
20 9.08 33.86 23.31 11.60 457.11 18.69
21 8.22 33.39 24.07 9.28 449.80 18.39
22 7.65 32.09 22.76 11.66 471.71 18.68
23 8.48 32.51 25.08 9.89 464.41 18.52
24 9.03 28.30 23.20 10.44 466.60 18.61
25 11.17 30.21 24.83 11.25 475.73 17.75
26 12.47 30.15 21.31 11.26 458.57 19.29
27 11.67 29.07 23.62 10.49 477.19 18.01
28 11.37 28.12 22.09 10.54 476.82 18.33
29 12.74 18.97 21.50 11.41 462.58 18.25
30 10.43 25.74 23.94 11.88 466.96 17.53
31 9.54 28.70 26.01 9.53 489.60 19.13
32 8.15 28.17 24.69 10.80 477.92 18.50
33 9.36 30.79 25.02 13.02 488.14 18.40
34 10.19 30.92 23.10 9.89 467.69 17.65
35 9.28 31.99 24.26 11.64 470.61 17.10
36 10.93 28.91 27.39 11.91 458.20 18.01
37 7.08 31.16 25.04 11.18 463.68 18.47
38 9.42 30.11 25.48 11.34 478.28 18.33
39 11.74 29.69 23.93 10.27 469.88 18.06
40 12.17 28.11 22.99 11.64 459.30 18.33
41 14.36 29.95 22.82 11.80 464.77 18.02
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure7:The29LAICPMSanalysispointsparallelwiththegirdle(Figure6)forthepolisheddownthinsliceofsapphire#4showingrelativelyevenconcentrationsofMg,Ti,V,CrandGaacrosstheanalysisline.
Figure8:The29analysispointstakenparalleltothegirdleonthepolisheddownthinsliceofsapphire#4showthat there is ahigher concentrationofBe towards theedges (the surfaceof theoriginal faceted stone) (1213ppma)comparedwiththeconcentrationstowardsthecenter(68ppma).
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure9:The12analysispointstakentabletoculetonthepolisheddownthinsliceofsapphire#4donotshowasimilardropintheconcentrationsofBetowardsthecenterofthestone.
Inclusionscenes
Of the fivesubmitted,onestone (number4Figure5)was found toberelatively freeof inclusions,while the remainder revealed numerous inclusion scenes but all reminiscent of those normalfollowinghightemperatureheatingTheinclusionscenesaredepictedinFigure10,Figure11,Figure12,andFigure13.
Stonenumber1(Figure5)wasalittleunusualasitcontainednumerous(previoustoheating)crystalsthathadmeltedresulting in theirreplacementwithwhat isprobablyglasswithashrinkagebubble(Figure 10). Stone number 2, (Figure 5) revealed the total destruction of individual (previously)crystals(fromhightemperatureheating)thatareseennowtobesurroundedbyfinecloudsofpinpoint inclusions(observedwithreflected lightfromanopticalfiber)(Figure11). Instonenumber3(Figure5) thetreatmentprocess left tracesofartificiallyhealed tubes,circularand indistinctcoiledspringlikeformations(previouslyreportedasbeingcharacteristicofBetreatedbluesapphires)andheatdestroyed(previously)crystalssurroundedbyfinecloudsofpinpointinclusions(Figure12).Instone#5(Figure5)coiledspringlikeandweblikeformationsthathavepreviouslybeenreportedascharacteristicofBe treatedblue sapphires are present as are heat destroyed (previously) crystalssurroundedbyfinecloudsofpinpointinclusions(Figure13).
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure 10: The inclusion scenewithin an oval 0.891ct (stone #1 Figure 5)Be treated blue sapphire revealingindicationsofthehightemperatureheatingenvironmentithadexperiencedduringthetreatmentprocess.Topleft;localizedcreatedand/oralteredhealedfracturessurroundingamyriadof(previously)crystalinclusions.Topright and bottom left; melted (previously) crystals with shrinkage bubbles. Bottom right; a group of small(previously)crystalsdestroyedduringthetreatmentprocess.
Figure11: The inclusion scenewithin anoval0.874ct (stone#2, Figure5)Be treatedblue sapphire revealingindicationsofhightemperatureheating.Allimagesshowthetotaldestructionofindividual(previously)crystalswith top leftand right,aswell asbottom left showing that theseare surroundedby fine cloudsofpinpointinclusions(seeninreflectedlightfromanopticalfiber).
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure12: The inclusion scenewithin anoval1.101ct (stone#3, Figure5)Be treatedblue sapphire revealingindicationsofhigh temperatureheating. Top left tracesofartificiallyhealed tubes, top rightandbottom leftcircularand indistinct coiled springlike formations thathavepreviouslybeen reportedas characteristicofBetreatedbluesapphires.Bottomright,heatdestroyed(previously)crystalssurroundedbyfinecloudsofpinpointinclusions(seeninreflectedlightfromanopticalfiber)asseenalsoinFigure10.
Figure 13: The inclusion scenewithin an oval 0.883ct (stone #5 Figure 5)Be treated blue sapphire revealingindications of a high temperature heating environment. This stone displays coiled springlike and weblikeformations(bottomleftandright)reportedasbeingcharacteristicofBetreatedbluesapphires.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure14:Stonenumber4afterbeingpolishedtoathinslice(1.03mm),seehere immersed indiiodomethane.Nocolorzoningwasobserved,eitherintermsofnaturalgrowthorsurfaceconformal(thewhiteareatopleftandthegrayareabottomrightjustinsidetheedgeofthestoneisrelatedtoremainingfacetrefection)
Colorzoning
Each of the five Be treated blue sapphires (Figure 5 and Figure 14)were examined immersed indiiodomethane (RI 1.74) to observe any color zoning thatmay be present. No colorless rims asobservedandreportedbyGAAJ(Kitawaki,2006)(Figure15)werefoundtobepresent inanyofthefive stones,and the slightdiscoloration fromblue tograyat the rimdescribedbyPeretti (Peretti,2005a) was also not observed in these samples. No other kind of surface conformal zoning waspresentinanyofthestones,e.g.,seeFigure14,andangularbluecolorzoningwasobservedonlyinstone#5.Nobluecolorzoningwasobservedinstones1to4althoughstraightbrown(rutile)zoneswerenotedinstone#3aswerebrownhalossurroundingdestroyedcrystalsinstone#3.
Figure15:ColorlessrimstoheatedbluesapphiresinwhichBewasdetectedbyresearchersattheGemmologicalAssociationofAllJapaninJuly2003(left)wheretherimappearedtobesurfaceconformalandJuly2004(right)wheretherimwasnotsurfaceconformal.GAAJ.PhotoGAAJ
Fluorescence:
All fivestoneswere found tobe inert toSWultraviolet lightbut fluoresced red tovaryingdegreesunder LW ultraviolet light. This red fluorescence was recorded in greater intensity using the
DiamondView (The Diamond Trading Company) at 2.5sec integration, 16.00db gain and a fullapertureatfullpower(Figure16,Figure17,Figure18,Figure19andFigure20).
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure16:Stonenumber1(Figure5)innormallight(left)andintheDiamondView(right)
Figure17:Stonenumber2(Figure5)innormallight(left)andintheDiamondView(right)
Figure18:Stonenumber3(Figure5)innormallight(left)andintheDiamondView(right)
Figure19:Stonenumber4(Figure5)innormallight(left)andintheDiamondView(right)
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure20:Stonenumber5(Figure5)innormallight(left)andintheDiamondView(right)
UV/visibleandIRspectroscopy
TheUV/visible spectrawere recorded forboth theO and E rays andmay be compared in Figure21,Figure22,Figure23,Figure24andFigure25.Theabsorptionedge isgivenarbitrarily foreachspectrumat9.5cm1. It is interestingtonoteboththedifferences inapparentcolorofthesamples(Figure 5) and the variables in visible spectra. The absorption edge varies from 298.5 to 310nmbetweenthesamplesandtheheightoftheshoulderat330nmvariesfromapproximately1.25to3.5cm1.Stonenumber3(1.101ct),thedarkestofthefive,presentedanentirelydifferentspectrumtotheother fourwitha relativelystrongabsorbanceataround880nm; italsocontained thegreatestamountofFe(Table2).
OFechargetransfer
Fe2+Ti4+
Fe3+Fe3+ Oray
Fe2+Ti4+
Eray
Figure21:Theabsorptionspectraobtainedfromanoval0.891ctBetreatedbluesapphire.Theabsorptionedgeisgivenarbitrarilyat9.5cm1.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure22:Theabsorptionspectraobtainedfromanoval0.874ctBetreatedbluesapphireTheabsorptionedgeisgivenarbitrarilyat9.5cm1.
Fe2+Ti3+
Figure23:Theabsorptionspectraobtainedfromanoval1.101ctBetreatedbluesapphire.Theabsorptionedgeisgivenarbitrarilyat9.5cm1.
Figure24:Theabsorptionspectraobtainedfromanoval1.209ctBetreatedbluesapphireTheabsorptionedgeisgivenarbitrarilyat9.5cm1.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure25:Theabsorptionspectraobtainedfromanoval0.883ctBetreatedbluesapphireTheabsorptionedgeisgivenarbitrarilyat9.5cm1.
Intheinfraredtheonlycommonpointofinterestinallfivesampleswastheconsistentpresenceofapeaklocatedat3209cm1;thepeakheightvaryingfromapproximately0.02to0.09cmcm1(Figure26).Whatthispeak isrelatedto isstilluncertainalthoughasimilarpeak isobservedwithinthePunsiritype spectrum recorded for the largerBe treated stones (Figure33andFigure35)described later.Further spectra are presently being recorded on a larger number of similar sizedBe treated bluesapphiresintoestablishwhetherornotthispeakisconsistentandpossiblyrelatedtosomeelementofthetreatmentprocess.AhmadjanAbduriyimofGAAJalsoconfirmsthepresenceofthe3209peakinBetreatedbluesapphiresexaminedinJapan(Abduriyim,2009).
Figure26:Intheinfraredspectraallfivesamples(Figure5)aclearfeaturewasrecordedcenteredat3209cm1.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure27:Greaterdetailofthe3209cm1instonenumbers1and2.
Figure28:Greaterdetailofthe3209cm1instonenumber3showingtwosmallsidebandsat3104and3315cm1.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Twolargeberylliumtreatedbluesapphires
While theyhavebeen reported (Peretti,2005a), large sizes inBe treatedblue sapphireshaveonlybeenrarelysubmittedtothe laboratoryforexamination;so itwasa littlesurprisingwhenberylliumwasdiscoveredintheheated22.52ctbluesapphireseeninFigure1,andwithinamatterofdaysthiswasfollowedwiththesubmissionofthe55.88ctsstoneseen inFigure29whereberylliumwasalsorecorded.Furtherexaminationofthetraceelementcompositionprovidingsufficientinformationtoconcludethatinbothcasesthestoneshadbeenberylliumtreated.
In thecaseof the second stone (55.88ct) it transpired thatoneof theownersactually treated thestone. He asked ifwewould like to visit him at his facilitywherewe could talk about the newberyllium treatment technique he was using to produce these relatively large Sri Lankan bluesapphires.Thismeetinghastakenplacewithrelevantdetailsofthisandfutureplannedmeetingstobeaddedtothispaperatalaterstageintheresearchprocess.
Berylliumandothertraceelementcontent
Uponreceiptofeachofthesetwostones(Figure1andFigure29)itwasfirstlydeterminedthroughamicroscopicexaminationoftheirinclusionscenes(e.g.,Figure30,Figure31andFigure32)thattheywereheatedandasperprocedure2theirtraceelementcompositionwasanalyzedusingLAICPMS.ThreespotswerechosenforanalysisoneachstoneandtheresultsaresetoutinTable5andTable7.Bothstoneswerefoundtocontainberylliumwiththelevelsrangingfrom7.50to18.17ppma.Otherelement levels were also recorded with Nb and Ta having no concentrations indicating that theberylliumhadbeenaddedartificiallyduringtheheatingprocess(Shen,2007,Shen,2009).
Figure29:A55.88ctberylliumtreatedbluesapphire.
2Procedure in such cases requires thatheated corundum is analyzedusing LAICPMS and that inparticulartheconcentrationsforBe,Ta,andNbarerecorded.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Table 4: The Be concentrations (in ppma) in three spots examined on the 55.88ct Be treated blue sapphiredepictedinFigure9.DatacollectedbyLAICPMS
Sample Beinppma
53.88ctBetreatedbluesapphire,spot1 13.0053.88ctBetreatedbluesapphire,spot2 17.1253.88ctBetreatedbluesapphire,spot3 18.17Table5:Traceelementconcentrations (inppma) in the55.88ctBe treatedbluesapphiredepicted inFigure9.DatacollectedbyEDXRF
Sample Ti V Cr Fe Ga
53.88ctBetreatedbluesapphire 38.3 3.8 0.04 168.07 19.98Table 6: The Be concentrations (in ppma) in three spots examined on the 22.52ct Be treated blue sapphiredepictedinFigure1.DatacollectedbyLAICPMS
Sample Beinppma
22.52ctBetreatedbluesapphire,spot1 7.5822.52ctBetreatedbluesapphire,spot2 7.6522.52ctBetreatedbluesapphire,spot3 9.46Table7Traceelementconcentrations (inppma) in the22.52ctBe treatedblue sapphiredepicted inFigure1.DatacollectedbyEDXRF
Sample Ti V Cr Fe Ga
22.52ctBetreatedbluesapphire 84.67 3.20 BDL 53.45 21.15
TheirchemistrywasalsoanalyzedusingEDXRF 3andtheconcentrationsforTi,V,Cr,FeandGaarelistedinTable6andTable8
Inclusionscenes
Both the 22.52ct and the 53.88ct beryllium treated blue sapphires are relatively clean internally.Noneof the inclusions typicalofberyllium treatedblue sapphires (Peretti,2005a, Shen,2007) asdepicted inFigure3,Figure10,Figure11,Figure12andFigure13areevident. Figure30,Figure31and Figure32depict theonlynear surface and internal featurespresent in the two stones; thesefeaturesbeingindicativeofheattreatmentonly.
3 EDXRF (Energy Dispersive Xray Fluorescence) is a fast technique used for bulk analyses whereconcentrationsofelementsNaandabovearedesired.ThesamestandardsareusedbothforEDXRFandLAICPMS.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure 30:A surfacebreakingheat alteredhealed fracture recorded in thehe 55.88ctberyllium treatedbluesapphiredepictedinFigure29.
Figure31:Nearsurfacefeathering,afeatureoftenassociatedwithheatedsapphires,recordedinthehe55.88ctberylliumtreatedbluesapphiredepictedinFigure29.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure32:Animageoftheinclusionscenewithinthe55.88ctberylliumtreatedbluesapphiredepictedinFigure29.ThestoneisrelativelycleaninternallyandcontainednoneoftheinclusiontypesdepictedinFigure10,Figure11,Figure12orFigure13.
Fluorescence:
ContrarytothesmallerstonesdescribedabovebothoftheselargestoneswerefoundtobeinerttoLWandSWultravioletlight.
UV/visibleandIRspectroscopy:
Given that these two large sapphires are production stones rather than research stones theamountofdatacollectedislimitedtotherequirementsofthereportandachievingareliableresult.In cases where an identification of the stone (and any treatments) is the only requirement thecollectionofIRspectraisnormalprocedure,however,unlessanorigindeterminationisrequiredthecollectionofUV/visiblespectraisnotnormal.
ForthesetwolargestonestheIRspectrawererecordedwithsimilarresults.Inadditiontoapeakat3209 that ispresent in the five smaller stonesdescribedearlier (Figure26), these largeBe treatedblue sapphires recorded broad peaks at 3112, 3057 and 2628 (Figure 33 and Figure 35). ThesespectraresemblethemultibandstructureseeninsomePunsiritypeheatedbluesapphiresrecordedinthepast(AGTAGTC,2003,AGTAGTC,2004b,AGTAGTC,2004a).
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure33:Inadditiontothepeakat3209thatispresentinthefivesmallerstonesdescribedearlier(Figure26),this22.52ctBetreatedbluesapphirehaspeaksat3112,3057and2628.Showingastrongresemblancetothemultiband structure seen in somePunsiritypeheatedblue sapphires recorded in thepastand to thatof the53.88ctdescribedherein(Figure35).
Figure34:Amixed(OandE)rayspectrumofthe53.88ctberylliumtreatedbluesapphiredepictedinFigure29.Theabsorptionedgeat9.5cm1issituatedat297nm.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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Figure35:Inadditiontothepeakat3209thatispresentinthefivesmallerstonesdescribedearlier(Figure26),this53.88ctBetreatedbluesapphirehaspeaksat3112,3057and2628.Showingastrongresemblancetothemultiband structure seen in somePunsiritypeheatedblue sapphires recorded in thepastand to thatof the22.52ctsapphiredescribedherein(Figure33).
For theUV/visible theonly spectrum recordedwas that for the53.88ct stone. Thiswas a surveyspectrum(Figure34)withnoattemptmadetorecordseparateOandErays.However,thespectrumisofthetypeonewouldexpectfromaSriLankanbluesapphirethathasbeenheated.Moredetailedspectraofthisstonetypewillbeforthcomingasthisprojectcontinues.
Discussion
The foregoingobservationsonberylliumtreatedbluesapphiresconstitutesapreliminary foray intoan importantareaofgemstone treatment that,with theadventof largeBe treatedbluesapphiresreachingthemarket,mayrequiregemologiststoexaminemorecloselythosestonesthatrevealanysignsofheattreatment.
From the data obtained with this small group of stones, it would appear that a more rigorousapproachtounderstandingoftheprocessesinvolvedandtotheinterpretationofresultsisneededtobetterunderstandtheeffectsofBediffusioninbluesapphire.
Unlike previous experiences with Be treated yellow, orange and smaller blue stones, the treaterresponsibleforthelargersizesseemstobewillingtosharehistechnique/methodwiththeauthorsandthususheringinaratherrefreshingeraofgreatertransparency.Detailsofamoreindepthstudyof the technique and the before and after treatmentmaterialswill be added to this text in duecourse.
DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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DuToit,G., Thanachakaphad, J., Scarratt, K. (2009) Beryllium Treated Blue Sapphires: Continuingmarket observations andupdateincludingtheemergenceoflargersizestones.June25th2009.OngoingResearch,http://www.giathai.net/lab.php
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