Gemstones of the World by Walter Schumann
This is the standard reference for over twenty years, now completely revised and updated with many new illustrations. Gemstones of the World is the most comprehensive and informative colour manual of the world's gemstones and includes more than 1,400 examples. Opposite each illustration the text provides an exact description of the particular stone, including details of the properties and chemical composition which makes the stone unique. Information on location of major deposits, alternative names, stones most easily identified incorrectly, and diagrams of their crystal habits are also given. The tables on gemstones' properties and constants provide a basic system of elimination for all unidentified stones. There are also eleven tables listing commercial and mineral names, refractive indices, dispersion, pleochroism, fluorescence, absorption spectra and specific gravities of gems. From the historical to the scientific, this extraordinary reference source is filled with fascinating facts about gemstones, both precious and semi-precious. It's also a worldwide scientific survey, with stunning colour photographs of each gem and its varieties.