Feature Gems & Gemology, Summer 2010, Volume 46, No. 2

A New Type of Composite Turquoise


Several conspicuously colored specimens marketed as dyed and/or stabilized turquoise were recently examined. They were purple to purple-pink, yellow-green, and blue, in veined and unveined varieties. Testing revealed that all the specimens were composites of turquoise pieces bonded together; the purple to purple-pink and yellow-green samples were bonded with a colored polymer, and the blue ones had a colorless polymer. This article presents the gemological properties and EDXRF and FTIR analyses of this material, along with its reaction to the solvents acetone and methylene chloride.