Oxygen isotope systematics of emerald: relevance for its origin and geological significance

Oxygen isotopic composition of emerald from 62 occurrences and deposits in the world reveals a wide range in δ^sup 18^O (SMOW) between +6.2 and +24.7[per thousand]. The δ^sup 18^O-values for each deposit are restricted and can be used to determine the origin of emerald from the world's most important producers. The δ^sup 18^O-value of emerald appears to be a fingerprint of its origin, especially for gems of exceptional quality from Colombia (eastern emerald zone, δ^sup 18^O=+16.8±0.1[per thousand]; western emerald zone, δ^sup 18^O= +21.2±0.5[per thousand]), Afghanistan (δ^sup 18^O=+13.5±0.1[per thousand]), Pakistan (Swat-Mingora districts, δ^sup 18^O=+15.7±0.1[per thousand]), Brazil (Santa Terezinha de Goiás, δ^sup 18^O=+12.2±0.1[per thousand]; Quadrilatero Ferrifero, δ^sup 18^O=+6.9±0.4[per thousand]) and Zimbabwe (Sandawana, δ^sup 18^O=+7.5±0.5[per thousand]). Furthermore, the ^sup 18^O-composition of emerald appears to be a good marker of its geological environment because the data suggest that host-rock-buffering of fluid δ^sup 18^O is considerable during fluid-rock interaction.[PUBLICATION ABSTRACT]