This revised edition covers the latest gems, synthetics, treatments and instruments. It is easy to use, practical and non-technical indicating how to identify diamonds, coloured gemstones and pearls, as well as separating them from fakes and look-alikes. The book explains what instruments are needed and how to use them, where to obtain such instruments and what should be seen for each gemstone. Anyone can learn to identify most of the gems and imitations found in the market place. This volume is the key to avoiding costly mistakes and recognising profitable opportunities.