Descriptions of Gem Materials is the most complete reference on natural and man-made gem materials available for gem cutters, gemologists and all others with an interest in gemstones. It provides a basis for gem identification and prepares the cutter for what may be expected when cabbing, carving or faceting a particular material. It covers the physical and optical properties for 346 distinct natural minerals and 56 man-made gems, more than 550 gem materials in all. Included are complete sets of tables for hardness, specific gravity and refractive index and information on common inclusions for each mineral. Acomplete list of varietal, alternate and incorrect names is presented and the pronunciation and derivation of gem names is provided.