The heat treatment of corundum involving lattice diffusion of beryllium (Be) at temperatures over 1800°C has become a major issue in the gem trade.
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This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
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This study provides detailed mining and gemmological information on the Jegdalek deposit, in east-central Afghanistan, which is hosted by elongate beds of corundum-bearing marble.
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Gem-quality rubies and pink to purple sapphires are being recovered from the Luc Yen and Quy Chau mining regions of Vietnam.
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In early 2004, the GAAJ laboratory in Japan issued a lab alert about rubies they had seen that had large numbers of fractures filled with high-lead-content glass, which made them appear very transparent.
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Kyocera Corporation of Kyoto, Japan, is currently marketing under the trade name "Inamori" a macroscopically natural-appearing semitransparent asteriated synthetic ruby.
Read MoreGem-quality rubies and fancy-colour sapphires have been recovered from dolomite marble lenses located high in the Himalayan mountains of east-central Nepal (Ganesh Himal).
Read MoreThe gemmological properties of a new ruby imitation, produced by dyeing natural colourless to pale-coloured corundum, are described.
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During the past 25 years, the corundum market has been transformed from one of medium to high-priced gems to one that encompasses nearly all price ranges.
Read MoreAn overview of the many types of gem-quality material, and its inclusions, currently found in Sri Lanka.
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