corundum, synthetic corundum.7, gems

Gübelin describes the diagnostic characteristics of the newer flux-grown synthetic rubies produced by Chatham, Kashan and Knischka. Particular emphasis is placed on microscopic examination of their characteristic inclusions, some of which may resemble features encountered in natural ruby and therefore complicate identification. The article illustrates and compares the internal features of the three products, showing how inclusion morphology and growth-related characteristics can be used to distinguish these synthetic rubies from natural stones. The paper contains 42 figures, 41 in color.