Inclusions in Natural, Synthetic, and Treated Diamond

Abstract

See end of article for About the Authors. GEMS & GEMOLOGY, Vol. 54, No. 4, pp. 428–429, http://dx.doi.org/10.5741/GEMS.54.4.428 © 2018 Gemological Institute of America many gem-quality diamonds are free of such diagnostic characteristics and will require advanced gemological testing to determine whether they are mined, laboratory grown, or treated. For example, chromian garnet inclusions can indicate the diamond formed in a peridotitic environment, while omphacite and kyanite would suggest an eclogitic environment. Other features that are notably diagnostic to the gemologist are so-called “flash-effect” colors that decorate lead glass–filled fractures and tapering tubes that indicate laser drilling. Gem-quality synthetic diamonds have been commercially available since 1986; however, recent im-