A practical pocket-sized guide to the identification and use of precious and semiprecious stones, novelty stones, agates and crystals. The introductory part of the book describes the geology, chemistry and properties of gemstones in clear and accessible terms. The important properties of gemstones are explained, including crystal structures and optical and physical properties, and the book also examines synthetic gems and discusses how to tell them apart from natural stones. It then covers practical aspects of gemmology and the use of stones, including fashioning and cutting, types and shapes of cut, collecting, handling and storing gemstones, and weighing and measuring stones.