The chemistry, properties and tests of precious stones

A practical handbook examines the origin, physical and chemical characteristics, and identification of precious stones. It describes crystalline structure, cleavage, optical behavior such as refraction, double refraction and play of colour, plus colour origins, hardness, specific gravity, thermal and electromagnetic responses, and cutting techniques. Chapters on imitations and simple empirical tests teach how to distinguish genuine gems from substitutes and assess quality. The text combines technical exposition with practical guidance for collectors and dealers, emphasizing observational methods that determine durability, suitability for cutting and setting, and basic valuation criteria.