Feature Gems & Gemology, Winter 1991, Vol. 27, No. 4

An Examination of Nontransparent “CZ” from Russia

White, pink, and black nontransparent synthetic "cubic zirconia" is currently being manufactured in Russia and marketed primarily in cabochon and bead form. These unusual materials are potentially useful as substitutes for such gem materials as pearl, dyed black chalcedony ("onyx"), and even black diamond. The authors provide a detailed description of these new products, including the chemistry and probable manufacturing techniques. These products can be readily identified by standard gemological tests.