This book has tons of information about gems, with the high points being the classification of gems, and the final chapters dealing with the industry and being a collector. The vast majority of the book is devoted to describing particular gems, and though this is informative, the gems are not organized in any scheme that makes them easy to find. That reduces the value of this book as a reference book quite a bit. Still, the pictures are more than adequate and the amount of information make this book useful, just not as useful as it should have been. ( )