Feature Gems & Gemology, Winter 1993, Vol. 29, No. 4

The Gemological Properties of Russian Gem-Quality Synthetic Yellow Diamonds

A group of gem-quality synthetic diamonds, grown in Russia using the "BARS" apparatus and now being sold for jewelry use, is examined. Study of seven yellow (five faceted, 0.11-0.51 ct) to orangy or brownish yellow as-grown samples, and three yellow to greenish yellow samples (all faceted, 0.14-0.21 ct) reportedly treated by post-growth annealing at high pressure and temperature, revealed distinctive gemological properties. These include: color and luminescence zoning, metallic inclusions, graining, and sharp visible-range absorption bands (some seen with a handheld spectroscope).