Feature Gems & Gemology, Summer 2004, Vol. 40, No. 2

Lab-Grown Colored Diamonds from Chatham Created Gems

Synthetic colored diamonds (yellow, blue, green, and pink) from a new source in Asia are now being sold by Chatham Created Gems of San Francisco, California. Some of this new material displays hues and weaker saturations that more closely resemble natural diamonds than most of the synthetic diamonds we have encountered previously, which typically had very intense colors. These as-grown and treated type I and type II synthetic diamonds, produced by a high pressure/high temperature process, have many distinctive visual and spectroscopic features that serve to separate them from natural diamonds. These include geometric patterns of color zoning and luminescence, metallic inclusions, and bands seen in the visible and photoluminescence spectra.