Diamond Handbook: How to Identify & Evaluate Diamonds
Book Review by Eric J. Hoffman
Renée Newman, International Jewelry Publications, 2018. Revised and updated 3rd edition. 168 + (8) pp, more than 350 color illus, 9" x 6". $19.95
It takes a lot of courage to be a diamond dealer these days. Or even a purchaser of high-end diamonds. Especially within the past decade or so, as the number of diamond treatments, enhancements, and imitations has flourished, the task has become ever more challenging. This handbook, by renowned gemologist Renée Newman, will arm you with the information you need.
Ms. Newman begins by explaining the physical characteristics of diamond, including brightness, brilliance, and fire. Some of these physical properties form the basis for modern electronic diamond detecting instruments. The important role of lighting in evaluating diamonds is discussed, as well as practical advice on how to choose and use a loupe.
The well-known "4 C's" (color, cut, clarity, and carat weight) no longer suffice for evaluating and pricing diamonds. An entire chapter explains the additional factors needed today. Cut quality is especially well covered, with clear and useful photographs of such cut-induced defects as windowing, "fisheye," and "nailhead." The photographs throughout the book, in fact, add immensely to its value. Because round brilliants are so widely sold they receive their own dedicated discussion of cut quality. And the subject of diamond fluorescence is well covered and illustrated, including the debate of whether it adds value or detracts.
Diamond clarity grades can be confusing but this book explains them well, again with helpful close-up photographs. A later chapter explains (and shows) some of the methods for improving clarity, such as laser drilling and fracture filling. The coverage in these two chapters is the next best thing to taking these sections of a GIA diamond grading course.
An important chapter explains how to tell real diamonds from imitations, and natural diamonds from synthetic. As synthetics have gotten better and more commonplace, laboratory methods may be required. Another entire chapter deals with the many diamond treatments, especially those to improve color. These have come a long way from Georgian period foil backing and now include coating, irradiation, and HPHT (high pressure high temperature) treatments, among others.
"Fancy" colored diamonds require some special considerations, especially in judging their color; these are thoroughly covered in a dedicated chapter. Even if you could never afford a fancy colored diamond you may enjoy ogling the gorgeous photographs. Likewise, evaluating and appraising old cuts of diamonds in antique jewelry requires special knowledge that is covered in depth in its own chapter. This includes a capsule history of cuts going all the way back to Indian diamond cutters in the 1300s.
"Branded" diamonds, with guaranteed quality and special cuts very different from the standard round brilliant, receive their own chapter. Twenty-five branded examples are discussed and shown. And one of the more fascinating chapters deals with recutting diamonds, which can improve not only the cut but the clarity grades and even the color. The recut stone, even though somewhat smaller, may increase substantially in value. Several interesting examples, well illustrated with photographs, demonstrate this point.
Despite the immense amount of information in this book it is well organized and surprisingly easy to read. Ms. Newman's writing is well known for being clear and succinct. If you are at all interested in diamonds, either as a jewelry professional, a high-end collector, or a retail customer, this is the book for you.
Copyright © 2018 by Eric J. Hoffman (Home Page)
Originally published in ASJRA Newsletter, Feb-March 2018