Feature Gems & Gemology, Fall 1983, Vol. 19, No. 3

The Identification of Turquoise by Infrared Spectroscopy and X-Ray Powder Diffraction

A combination of infrared spectroscopy and X-ray powder diffraction methods is suggested for the identification of natural, treated, and synthetic turquoise as well as imitation turquoise. Both techniques require powdering only a very small quantity of the specimen (approximately 3 mg), which means minimal damage to the piece. New experimental results on treated turquoise and imitation turquoise are given.