Sapphire-ruby characteristics, West Pailin, Cambodia: clues to their origin based on trace element and O isotope analysis

Sutherland, F.L., Giuliani, G., Fallick, A.E., Garland, M. and Webb, G. (2009) Sapphire-ruby characteristics, West Pailin, Cambodia: clues to their origin based on trace element and O isotope analysis. Australian Gemmologist, 23(9), pp. 373-432.

Abstract

Trace element (Particle-induced X-ray emission) and oxygen isotope (B¹⁸O) analyses on West Pailin, Cambodian sapphires and rubies further constrain the geochernical characteristics of this basalt-derived, bimodal (two corundum types) gem deposit. The results confirm a clear distinction between magmatic origin sapphires (Fe 2300-8000ppm, Ti 15-1800ppm, Cr below detection, Ga 160-260ppm; Cr/Ga <0.01; (B¹⁸O) 7.0-7.8 ‰) and metamorphic-origin sapphires and rubies (Fe 3300-9130ppm, Ti 60-3600ppm, Cr 160-5300ppm, Ga 28-46ppm; Cr/Ga 3.6-155; (B¹⁸O 4.0-4.9 ‰). Comparisons with a similar Australian bimodal corundum deposit from the Barrington Tops, basaltic gem field show some common features, although the West Pailin magmatic suite is more depleted in Fe and noticeably higher in (B¹⁸O values. The metamorphic suite is more enriched in Ti and Cr and distinctly lower in its (B¹⁸O range than its Barrington Tops counterpart. This allows geographic distinctions to be drawn between these bimodal corundum suites and indicates differences in the geological processes by which corundum crystallised under the two regions.

• Item Type: Articles
• Keywords: Sapphire, ruby, corundum, basalt field, trace elements, oxygen isotopes, gemstone genesis, Southeast Asia, Eastern Australia.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fallick, Professor Anthony
• Authors: Sutherland, F.L., Giuliani, G., Fallick, A.E., Garland, M., and Webb, G.
• Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Australian Gemmologist
• ISSN: 0004-917