GAHK$Seminar$23th$June$2012$ 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$SSEF$ Kashmir Sapphire 1!
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 2!
The velvety blue of Kashmir sapphires Photos H.A. Hänni, SSEF Sapphires$from$Kashmir$contain$subQ microscopic$inclusions$which$scatter$the$ transmitted$light.$$ $ As$a$result,$these$stones$often$show$a$$ highly$appreciated$velvety$blue$colour.$ Treasured by the Maharadja In$the$Padar$region$in$the$ Zanskar$mountain$range$$ The$Maharaja$of$Jammu$and$Kashmir,$circa$1900$ www.kashmirphotos.org/history.html$ 3!
The Kashmir sapphire mines from$tom$d.$latouche$(1890)$ Records(of(the(Geological(Survey(of(India.$ In$the$Padar$region$in$the$Zanskar$mountain$range:$ $ Q discovered$1880$ Q main$mining$operation$1882q1887$ Q sporadic$activity$between$$1888$ $1945$and$up$to$nowadays,$but$no$evident$production$of$ gemqquality$material$anymore.$ Origin determination is always an expert opinion 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.$ 4!
Coloured gemstones are formed during large-scale geological processes which have shaped the world as we know it today...! Foto: Baltoro-Gletscher, Karakorum; Guilhem Vellut via, WikiCommons! Kashmir sapphire Foto: Baltoro-Gletscher, Karakorum; Guilhem Vellut via, WikiCommons! 5!
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" 6!
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$2003)! Economically important sapphire sources Montana, USA Kashmir Burma (Myanmar) Q Kashmir-(India)- Q Burma-(Myanmar)- Q Ceylon-(Sri-Lanka)- Q Madagascar- Q Tanzania- Q Pailin,-Cambodia- Q Australia- Q Montana-(USA)- Q...- Tanzania Madagascar Cambodia Ceylon (Sri Lanka) Australia www.mygeo.info 7!
Origin determination: Combining$ classical$ approaches$ with$ advanced$ scienti`ic$ analytical$ methods$ Kashmir Sapphire Lot$3798- A$pair$of$sapphire$and$diamond$ ear$clips$by$cartier$ 4.70$and$4.60$ct$ SSEF$report$62271$$$ 8!
Pargasite$needles$(amphibole)$ xenomorphous-plagioclase- Short-prismatic-tourmalinecorroded-prismatic-zircon- uraninite-with-tension-cracks- Photos H.A. Hänni, SSEF 9!
Photos H.A. Hänni, SSEF `ine$dust$tracks$ netqlike$healing$`issures$ Photo H.A. Hänni, SSEF CrQenriched$growth$layers$ 10!
The Kashmir - Madagascar challenge! The Kashmir - Madagascar challenge! Photos H.A. Hänni, SSEF 11!
Madagascar sapphire Inclusion photos H.A. Hänni, SSEF Madagascar sapphire Inclusion photos H.A. Hänni, SSEF 12!
Madagascar sapphire Inclusion photos H.A. Hänni, SSEF The blurred picture: Sapphire The Kashmir Basaltic (e.g. Pailin) mix-up! Overlapping$irregular$growth$ (heterogeneous$growth)$ SSEF Photos: Swiss Gemmological H.A. Hänni, SSEF Institute Regular$growth$in$basaltic$sapphires$$ 13!
Ceylon sapphire Photos H.A. Hänni, SSEF SSEF Swiss Gemmological Institute UV-Vis Spectrometry SSEF Swiss Gemmological Institute" 14!
Raman microspectrometry Laser Ablation Inductively Coupled Plasma Mass Spectrometry LA-ICP-MS With Prof. Thomas Pettke! at the Geochemical Lab,! University of Berne, Switzerland! SSEF Swiss Gemmological Institute 15!
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.$ The LA-ICP-MS instrument Pettke, 2006! Microlas$system:$ Beam$modulation$optics$to$ homogenize$laser$beam$ energy$pro`ile$ Lambda$Physics,$Coherent:$ Pulsed$nanosecond$$ ArF$excimer$laser$(193$nm)$ Perkin$Elmer:$ DRCQe$quadrupole$mass$ spectrometer$ 16!
Laser ablation T. Pettke,, University Berne Local$heating$and$vaporization$ Important: Standardised Operation Procedures Q Q Laser$drill$holes$generally$60Q120$microns$(=0.06Q0.12$mm)$large$and$only$a$few$microns$deep.$ External$standardisation:$NIST$SRM$610$or$SRM$612$glass$standards$ Q Internal$standardisation$for$corundum$usually$99.5$wt%$Al 2 O 3$ Q Carrier$gas$helium$admixed$with$hydrogen$for$better$ablation$yield$and$transport$ Q To$correct$for$any$possible$instrumental$drift,$each$analytical$series$starts$with$two$analyses$on$ the$multiqelement$standard$(srm$610$or$612),$followed$by$maximum$16$analyses$on$the$ samples,$and$`inished$with$two$analyses$on$the$standard$again.$ $ $ 17!
Features of LA ICP MS Chemical$analysis$of$specimens$ +$nearly$all$chemical$elements$can$be$analysed$ +$up$to$50$elements$at$the$same$time$ +$point$analysis$(zoning)$ +$only$minor$sample$preparation$ +$large$dynamic$range$of$analysis$$ $$$(from$subqppm$to$main$element$concentrations)$ +$quantitative$data$ Photo:$Aeschlimann,$2003$ Q $slightly$destructive$analysis$(laser$drill$holes$diameter$ca$100$µm)$ Q $how$representative$are$point$analyses$for$the$whole$stone?$ Q $raw$data$(qualitative)$has$to$be$processed$to$get$quantitative$data$ Q$contamination$effects$ Q $spike$`iltering$ Q $highly$sophisticated$instrument$$ Research study with LAICPMS on sapphires Photo$ $P.$Halicki,$SSEF$ 18!
Data Raw processing data homogeneous$signal$ LA-ICP-MS Pearls 100000000 10000000 Ca 1000000 Mn counts 100000 10000 Ba I Mg 1000 100 Integration time 10 30 40 50 60 70 80 90 100 110 120 time (sec.) Setting$of$integrals$for$data$processing$is$easy$ 19!
Data processing Surface$contamination$!$ Surface$contamination$!$ Spikes$!$ Spikes$!$ Spikes$!$ 20!
Burma! Results: Madagascar! Sri Lanka! Kashmir! Results: Madagascar! Kashmir! Sri Lanka! Fe-(ppm)- Ti-(ppm)- Fe-(ppm)- Ga-(ppm)- 21!
Ti-(ppm)- Madagascar! Results: Madagascar$ Kashmir$ Burma$ Kashmir! Burma! Mg-(ppm)- Possibilities & Limitations: 20.12.2011 Peucat$et$al.$2007$ 1 Trace$element$ concentrations$ generally$indicate$ origin$ trends,$but$ are$often$not$ resulting$in$ conclusive$results.$ 22!
Conclusions: Q LAQICPQMS$is$a$sophisticated$analytical$method$$ $$$$$$$to$characterise$the$chemical$composition$of$gemstones.$ $ Q The$machine$produces$always$results,$but$are$they$real?$ $ Q $ Q $ Q $ Q Many$instrumental$parameters$have$to$be$controlled$to$produce$reliable$ results.$ The$raw$data$has$to$be$carefully$processed$to$$avoid$any$artefact$or$ contamination.$ For$sapphires,$large$overlapping$of$trace$element$concentration$ranges$occur.$ Thus,$the$origin$determination$of$sapphires$cannot$rely$upon$only$trace$ element$analyses,$but$needs$the$important$contribution$$of$$spectral$and$ microscopic$evidences.$ 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,! 23!
Thank you for your attention 24!