Artificial gemstones have been well established in the jewel trade for some time, but following further refinements in their manufacture, gemologists worldwide are facing increasing problems with their identification. Today, for instance, gem-quality synthetic diamonds--once deemed impossible to produce--are becoming widely available. The synthetic products of the past are still available as well, and often prove puzzling to newer generations of gemologists. Starting with the theory of synthetic gem manufacture and an explanation of the production methods used for growing and improving crystals, this definitive guide to the various manmade gem substitutes goes on to identify all existing artificial substances. The identifying internal and external features and tests are addressed, and color photographs illustrate the tell-tale features of both artificial and naturally occurring substances. Gemologists, gem dealers, curators, amateurs, and students alike will find this an indispensable resource.