HK June 2012 Kashmir sapphire - SSEF

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1 Kashmir sapphires: Potential and limitations of origin determination by chemical fingerprinting with LA ICP mass spectrometry Dr. Michael S. Krzemnicki & P. Halicki Swiss Gemmological Institute SSEF Photos © M.S. Krzemnicki, SSEF, except where indicated otherwise The data presented in this talk are the part of the Master thesis of P. Halicki, University Basel and SSEF GAHK Seminar 23th June 2012 Kashmir Sapphire

Transcript of HK June 2012 Kashmir sapphire - SSEF

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Kashmir sapphires: Potential and limitations of origin determination by chemical fingerprinting with LA ICP mass spectrometry

Dr.$Michael$S.$Krzemnicki$&$P.$Halicki$Swiss$Gemmological$Institute$SSEF$$Photos$©$M.S.$Krzemnicki,$SSEF,$except$where$indicated$otherwise$The$data$presented$in$this$talk$are$the$part$of$the$Master$thesis$of$P.$Halicki,$University$Basel$and$SSEF$

GAHK$Seminar$23th$June$2012$

Kashmir Sapphire

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© Swiss Gemmological Institute SSEF

11.01 ct SSEF Gemstone Report No. 63039 Sold for 10‘740‘000 HK$ at the Christies sale in HK in May 2012

Sapphires from Kashmir

© Swiss Gemmological Institute SSEF

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The velvety blue of Kashmir sapphires

Sapphires$from$Kashmir$contain$subQmicroscopic$inclusions$which$scatter$the$transmitted$light.$$$As$a$result,$these$stones$often$show$a$$highly$appreciated$velvety$blue$colour.$

Photos © H.A. Hänni, SSEF

© Swiss Gemmological Institute SSEF

© Swiss Gemmological Institute SSEF

In$the$Padar$region$in$the$Zanskar$mountain$range$$

Treasured by the Maharadja

The$Maharaja$of$Jammu$and$Kashmir,$circa$1900$www.kashmirphotos.org/history.html$

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© Swiss Gemmological Institute SSEF

from$Tom$D.$LaTouche$(1890)$Records(of(the(Geological(Survey(of(India.$

The Kashmir sapphire mines

In$the$Padar$region$in$the$Zanskar$mountain$range:$$Q  discovered$1880$Q  main$mining$operation$1882Q1887$Q  sporadic$activity$between$$1888$–$1945$and$up$to$nowadays,$but$no$evident$production$of$

gemQquality$material$anymore.$

Origin determination is always an expert opinion

© Swiss Gemmological Institute SSEF

The$origin$determination$of$gemmological$laboratories$is$always$based$on$scienti`ic$analyses$(trace$element$composition,$absorption$spectra),$inclusion$analyses$(e.g.$Raman$

microspectrometry$and$FTIR$spectrometry)$and$meticulous$microscopic$observations.$$

An$origin$of$a$gemstone$mentioned$on$a$gemstone$report$is$always$an$expert$opinion.$

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Foto: Baltoro-Gletscher, Karakorum; Guilhem Vellut via, WikiCommons!

Coloured gemstones are formed during large-scale geological processes which have shaped the world as we know it today...!

Kashmir sapphire Foto: Baltoro-Gletscher, Karakorum; Guilhem Vellut via, WikiCommons!

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The collision of the Indian plate with the Eurasian continental plate has produced some of the most important sources for coloured gems, such as the sapphires from Kashmir and the sapphires and rubies from Burma, and many more.!

Garnier et al. 2006!

Corundum in skarn!Andranondambo !

1994"

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Sapphires from East-Africa, Sri Lanka, Madagascar, and South India

Distribution$of$corundum$deposits$connected$to$PanQAfrican$tectonoQmetamorphic$events$(750Q450$ma)$by$the$collision$of$eastern$and$western$Gondwana.$$In$midQJurassic$(about$160$ma),$India$started$to$drift$towards$north.$

modi`ied$after$Collins$&$Windley$2002,$Santosh$&$Collins$2003)!

© Swiss Gemmological Institute SSEF

Tanzania

Australia

Kashmir

Burma (Myanmar)

Cambodia

Montana, USA

Ceylon (Sri Lanka)

Madagascar

© www.mygeo.info

Q  Kashmir-(India)-Q  Burma-(Myanmar)-Q  Ceylon-(Sri-Lanka)-Q  Madagascar-Q  Tanzania-Q  Pailin,-Cambodia-Q  Australia-Q  Montana-(USA)-Q  ....-

Economically important sapphire sources

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© Swiss Gemmological Institute SSEF

Origin determination:

Combining$classical$approaches$with$advanced$scienti`ic$analytical$methods$

Lot$3798-A$pair$of$sapphire$and$diamond$ear$clips$by$Cartier$4.70$and$4.60$ct$SSEF$report$62271$$$

© Swiss Gemmological Institute SSEF

Kashmir Sapphire

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Pargasite$needles$(amphibole)$

© Swiss Gemmological Institute SSEF

© Swiss Gemmological Institute SSEF

xenomorphous-plagioclase- Short-prismatic-tourmaline-

corroded-prismatic-zircon- uraninite-with-tension-cracks-Photos © H.A. Hänni, SSEF

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© Swiss Gemmological Institute SSEF

`ine$dust$tracks$

netQlike$healing$`issures$

Photos © H.A. Hänni, SSEF

© Swiss Gemmological Institute SSEF

CrQenriched$growth$layers$Photo © H.A. Hänni, SSEF

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The Kashmir - Madagascar challenge !

The Kashmir - Madagascar challenge !

Photos © H.A. Hänni, SSEF

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Madagascar sapphire

Inclusion photos © H.A. Hänni, SSEF

Madagascar sapphire

Inclusion photos © H.A. Hänni, SSEF

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Madagascar sapphire

Inclusion photos © H.A. Hänni, SSEF

The blurred picture: Sapphire

© SSEF Swiss Gemmological Institute

Regular$growth$in$basaltic$sapphires$$Overlapping$irregular$growth$(heterogeneous$growth)$

Photos: © H.A. Hänni, SSEF

The Kashmir – Basaltic (e.g. Pailin) mix-up!

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Ceylon sapphire

© SSEF Swiss Gemmological Institute Photos © H.A. Hänni, SSEF

UV-Vis Spectrometry

© SSEF Swiss Gemmological Institute"

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© Swiss Gemmological Institute SSEF

Raman microspectrometry

Laser Ablation Inductively Coupled Plasma

Mass Spectrometry LA-ICP-MS

© SSEF Swiss Gemmological Institute

With Prof. Thomas Pettke !at the Geochemical Lab, !University of Berne, Switzerland!

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© Swiss Gemmological Institute SSEF

The LA-ICP-MS instrument

The$instrument$at$the$Institute$of$Geological$Sciences,$University$of$Berne$(Switzerland)$has$been$optimized$for$analyses$of$minerals$and$`luid$inclusions$in$minerals.$

© Swiss Gemmological Institute SSEF

The LA-ICP-MS instrument

Lambda$Physics,$Coherent:$Pulsed$nanosecond$$ArF$excimer$laser$(193$nm)$

Microlas$system:$Beam$modulation$optics$to$homogenize$laser$beam$energy$pro`ile$

Perkin$Elmer:$DRCQe$quadrupole$mass$spectrometer$

Pettke, 2006!

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© Swiss Gemmological Institute SSEF

Laser ablation

© T. Pettke,, University Berne

Local$heating$and$vaporization$

© Swiss Gemmological Institute SSEF

Important: Standardised Operation Procedures

Q  Laser$drill$holes$generally$60Q120$microns$(=0.06Q0.12$mm)$large$and$only$a$few$microns$deep.$Q  External$standardisation:$NIST$SRM$610$or$SRM$612$glass$standards$Q  Internal$standardisation$for$corundum$usually$99.5$wt%$Al2O3$Q  Carrier$gas$helium$admixed$with$hydrogen$for$better$ablation$yield$and$transport$Q  To$correct$for$any$possible$instrumental$drift,$each$analytical$series$starts$with$two$analyses$on$

the$multiQelement$standard$(SRM$610$or$612),$followed$by$maximum$16$analyses$on$the$samples,$and$`inished$with$two$analyses$on$the$standard$again.$

$$

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© Swiss Gemmological Institute SSEF

Features of LA ICP MS

+$nearly$all$chemical$elements$can$be$analysed$+$up$to$50$elements$at$the$same$time$+$point$analysis$(zoning)$+$only$minor$sample$preparation$+$large$dynamic$range$of$analysis$$$$$(from$subQppm$to$main$element$concentrations)$+$quantitative$data$

Q $slightly$destructive$analysis$(laser$drill$holes$diameter$ca$100$µm)$Q $how$representative$are$point$analyses$for$the$whole$stone?$Q $raw$data$(qualitative)$has$to$be$processed$to$get$quantitative$data$Q$contamination$effects$Q $spike$`iltering$Q $highly$sophisticated$instrument$$

Chemical$analysis$of$specimens$

Photo:$Aeschlimann,$2003$

© Swiss Gemmological Institute SSEF

Research study with LAICPMS on sapphires

Photo$©$P.$Halicki,$SSEF$

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© Swiss Gemmological Institute SSEF

Data processing

LA-ICP-MS Pearls

10

100

1000

10000

100000

1000000

10000000

100000000

30 40 50 60 70 80 90 100 110 120

time (sec.)

co

un

ts

Mn

Ca

I

Ba

Mg

homogeneous$signal$

Setting$of$integrals$for$data$processing$is$easy$

Integration time

Raw data

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Surface$contamination$!$

Spikes$!$ Spikes$!$Spikes$!$

Surface$contamination$!$

Data processing

© Swiss Gemmological Institute SSEF

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Madagascar!

Kashmir!Sri Lanka!

Burma!

Fe-(ppm

)-

Ti-(ppm)-

Results:

Madagascar!

Kashmir!

Sri Lanka!

Fe-(ppm

)-

Ga-(ppm)-

Results:

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Madagascar$

Kashmir$

Burma$

Madagascar!

Kashmir!

Burma!

Ti-(ppm

)-

Mg-(ppm)-

Results:

20.12.2011 75

© Swiss Gemmological Institute SSEF

24.04.2012

Zentraler Weiterbildungskurs SGG

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Comparison

Peucat et al (2007) Kashmir this study

Trace$element$concentrations$generally$indicate$origin$„trends“,$but$are$often$not$resulting$in$conclusive$results.$

Possibilities & Limitations:

24.04.2012

Zentraler Weiterbildungskurs SGG

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Comparison

Peucat et al (2007) Kashmir this study

Peucat$et$al.$2007$20.12.2011 80

Thailand (Bo Phloi) + Cambodia

Peucat et al (2007)

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© Swiss Gemmological Institute SSEF

Q  LAQICPQMS$is$a$sophisticated$analytical$method$$$$$$$$$to$characterise$the$chemical$composition$of$gemstones.$$Q  The$machine$produces$always$results,$but$are$they$real?$$Q  Many$instrumental$parameters$have$to$be$controlled$to$produce$reliable$

results.$$

Q  The$raw$data$has$to$be$carefully$processed$to$$avoid$any$artefact$or$contamination.$

$Q  For$sapphires,$large$overlapping$of$trace$element$concentration$ranges$occur.$$Q  Thus,$the$origin$determination$of$sapphires$cannot$rely$upon$only$trace$

element$analyses,$but$needs$the$important$contribution$$of$$spectral$and$microscopic$evidences.$

Conclusions:

© Swiss Gemmological Institute SSEF

A guide to the world�s major sources of coloured gemstones, diamonds and pearls.!!

for more details see www.gemexplorer.org!also as a free App available in iTunes, !

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Thank you for your attention

© Swiss Gemmological Institute SSEF