Feature Gems & Gemology, Spring 1988, Vol. 24, No. 1

The Distinction of Natural from Synthetic Alexandrite by Infrared Spectroscopy

Infrared spectroscopy provides a means to distinguish natural from synthetic alexandrites in the range 2000-4200 cm -1, as determined by a study of spectra obtained from 15 natural and 28 synthetic alexandrites from a variety of sources. The technique is nondestructive and, with Fourier transform instrumentation, extremely rapid. It is especially useful for identifying stones that contain no distinguishing inclusions.