Lavishly illustrated with some 400 color photographs and other illustrations, this introduction to the world of gems and minerals contains some 225 alphabetical entries. Each mineral entry lists such scientific information as the characteristic mineral form, the specific gravity, the system of symmetry, the refraction, and the hardness of the mineral. Also included is a description of the mineral's physical properties, where it occurs in the environment, how it forms, its uses and value, and, particularly in the case of gemstones, its simulated and synthetic forms and how to recognize them. Annotation copyright Book News, Inc. Portland, Or.