Feature Gems & Gemology, Summer 1999, Volume 35, No. 2

Russian Synthetic Ametrine

Gem-quality synthetic ametrine has been produced commercially in Russia since 1994, by hydrothermal growth from alkaline solutions. Faceted synthetic ametrine has many similarities to its natural counterpart from Bolivia. For the most part, however, the synthetic ametrine obtained for this study could be identified by a combination of characteristics, including growth features such as twinning and color zoning. EDXRF chemical analyses revealed higher concentrations of K, Mn, Fe, and Zn than in natural ametrine. IR spectra of the synthetic citrine portions showed more intense absorption in the 3700–2500 cm−1 range compared to natural ametrine; the synthetic amethyst zones showed a weak diagnostic peak at 3543 cm−1.