TY - JOUR
T1 - Vanadium-rich ruby and sapphire within Mogok Gemfield, Myanmar
T2 - implications for gem color and genesis
AU - Zaw, Khin
AU - Sutherland, Lin
AU - Yui, Tzen Fu
AU - Meffre, Sebastien
AU - Thu, Kyaw
N1 - Funding Information:
Ross Pogson, Geoscience, Australian Museum, helped with geochemical plotting programs. Sang Ding helped in LA-ICP-MS analysis of the rubies and sapphires. This study is supported by CODES ARC Centre of Excellence, University of Tasmania. The authors are deeply indebted to reviewers and Georges Beaudoin, Editor-in-Chief, Mineralium Deposita for his insightful review, constructive comments, and suggestions to the substantial improvement of this manuscript.
Publisher Copyright:
© 2014, Springer-Verlag Berlin Heidelberg.
PY - 2014/1
Y1 - 2014/1
N2 - Rubies and sapphires are of both scientific and commercial interest. These gemstones are corundum colored by transition elements within the alumina crystal lattice: Cr3+ yields red in ruby and Fe2+, Fe3+, and Ti4+ ionic interactions color sapphires. A minor ion, V3+ induces slate to purple colors and color change in some sapphires, but its role in coloring rubies remains enigmatic. Trace element and oxygen isotope composition provide genetic signatures for natural corundum and assist geographic typing. Here, we show that V can dominate chromophore contents in Mogok ruby suites. This raises implications for their color quality, enhancement treatments, geographic origin, exploration and exploitation and their comparison with rubies elsewhere. Precise LA-ICP-MS analysis of ruby and sapphire from Mogok placer and in situ deposits reveal that V can exceed 5,000 ppm, giving V/Cr, V/Fe and V/Ti ratios up to 26, 78, and 97 respectively. Such values significantly exceed those found elsewhere suggesting a localized geological control on V-rich ruby distribution. Our results demonstrate that detailed geochemical studies of ruby suites reveal that V is a potential ruby tracer, encourage comparisons of V/Cr-variation between ruby suites and widen the scope for geographic typing and genesis of ruby. This will allow more precise comparison of Asian and other ruby fields and assist confirmation of Mogok sources for rubies in historical and contemporary gems and jewelry.
AB - Rubies and sapphires are of both scientific and commercial interest. These gemstones are corundum colored by transition elements within the alumina crystal lattice: Cr3+ yields red in ruby and Fe2+, Fe3+, and Ti4+ ionic interactions color sapphires. A minor ion, V3+ induces slate to purple colors and color change in some sapphires, but its role in coloring rubies remains enigmatic. Trace element and oxygen isotope composition provide genetic signatures for natural corundum and assist geographic typing. Here, we show that V can dominate chromophore contents in Mogok ruby suites. This raises implications for their color quality, enhancement treatments, geographic origin, exploration and exploitation and their comparison with rubies elsewhere. Precise LA-ICP-MS analysis of ruby and sapphire from Mogok placer and in situ deposits reveal that V can exceed 5,000 ppm, giving V/Cr, V/Fe and V/Ti ratios up to 26, 78, and 97 respectively. Such values significantly exceed those found elsewhere suggesting a localized geological control on V-rich ruby distribution. Our results demonstrate that detailed geochemical studies of ruby suites reveal that V is a potential ruby tracer, encourage comparisons of V/Cr-variation between ruby suites and widen the scope for geographic typing and genesis of ruby. This will allow more precise comparison of Asian and other ruby fields and assist confirmation of Mogok sources for rubies in historical and contemporary gems and jewelry.
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U2 - 10.1007/s00126-014-0545-0
DO - 10.1007/s00126-014-0545-0
M3 - Article
AN - SCOPUS:84939871955
SN - 0026-4598
VL - 50
SP - 25
EP - 39
JO - Mineralium Deposita
JF - Mineralium Deposita
IS - 1
ER -