Many tips and tricks for detecting treatments and how to differentiate between natural and synthetic materials are covered. Of particular interest in this latest edition is a section dedicated to identifying glass-filled rubies, which have plagued the market in the last few years. This chapter will clearly help even novice gem buyers and sellers avoid a costly mistake regarding this material.
However, this book lacks in the same measure of detail regarding diffusion treatment of corundum, which is at least as problematic in the gem trade as glass-filled rubies. The other area where it falls a bit short is image quality. Although color plates are included in this version, the images are small and in some cases very poor illustrations of their intended subjects. Most of the instructional images throughout the text are otherwise adequate.
Overall, this is a welcome addition to any gemological library, especially for the gemologist who must rely on portable instruments. If you’re in search of a “how-to” book full of vibrant images, this is not the one for you. If you are a gemologist at any level in need of a practical guide to gem testing or a reference guide, then you will be quite satisfied with this book.