Today buyers cannot be sure whether or not a gemstone is man-made, if its colour has been produced artificially and if it will survive life in a piece of jewellery. This book enables gemstone and jewellery buyers to find out for themselves. A wide range of gem and ornamental materials is described, species by species, opening up the secrets they sometimes conceal, such as when they can be artificially manufactured, when they can be cleverly imitated by other materials, and when their colour has been enhanced. Readers are told and shown what the tell-tale features are, and learn that while nothing is quite what it seems, there are ways in which they can spot give-away signs without needing to consult a laboratory.