"It is one of the more valuable texts available to mineralogists, gemologists, and advanced collectors . Gems should be kept on a handy shelf. I use my copy almost on a daily basis and consider it a very valuable tool, as well as a useful reference." - Bob Jones, Rock & Gem Reviews of the previous editions: "Any serious gemologist should have a copy available for ready reference." - Gems and Gemology "...a truly magnificent book." - New World "...this quintessential textbook and reference will serve yet another generation of students of gemology." - The Australian Gemologist