Robert Webster 
Practical Gemmology — A Study of the Identification of Gem-Stones, Pearls and Ornamental Minerals 

This vintage book contains an interesting and practical study of the identification of gemstones, pearls, and ornamental minerals. A comprehensive and profusely-illustrated handbook for both novice and experienced practitioners, this volume is not to be missed by anyone with a keen interest in the subject. The chapters of this book include: "Crystallography", "Physical Properties", "Specific Gravity", "Light", "Measurement of Refractive Index", "Colour in Gem Distinction", "The Microscope", "The Gem Species", "Synthetic Gems", "Imitation Gems", "Composite Stones and Artificially Induced Colour", etcetera. This book is being republished now in an affordable, modern, high quality edition — complete with a specially commissioned new introduction on gemmology.