corundum, quality.10, fashioning.9, cutting, gems

Sinkankas provides a comprehensive reference catalogue of gemstones intended for gemologists, jewelers, collectors, and mineral enthusiasts. The entries are arranged systematically and describe natural gem materials in terms of their mineralogical and gemological properties, including chemical composition, crystal system, hardness, specific gravity, refractive indices, optical character, color, cleavage, inclusions, and other diagnostic features. Discussions also cover important localities, occurrence, varieties, nomenclature, cutting and use, and methods of identification, with attention to materials that may be confused with one another. Synthetic stones, imitations, and less familiar ornamental materials are also considered where relevant. Designed for practical consultation rather than continuous reading, the volume brings together a large body of mineralogical and gemological data in a compact reference work for identifying and studying gem materials.