English

Gemmographical tables, giving the chemical composition, optical and physical properties of the gems

Cover title: Gemmographical tables for the use of diamond & gem merchants, jewellers & students : Exhibiting in tabulated form the distinguishing characteristics of rough and cut gems. "Tables of specific gravities, hardness, crystalline forms, cleavage, etc. Illustrations and descriptions of crystalline forms of gems. Names and colors of two hundred varieties. Twin colors of gems as seen in the dichroscope."--title page. "One of the earliest such compilations and designed to be practical and easily referrable. This appears to be the author's only published gemological work."--Gemology, J. Sinkankas, entry no. 5. Partial contents: Table 1. Names and colors of gems (transparent and non-transparent) -- Table 2. Table of the chemical composition and physical properties of gems -- Table 3. Crystalline forms of gems -- Table 4. The crystalline forms of diamonds -- Table 5. The twin colors of gems, as seen in the dichroscope.

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