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March-April 2014

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Media Reviews

Diamond Inclusions by Nizam Peters. American Institute of Diamond Cutting, PO Box 4067, Deerfield Beach, FL 33442; 208 pages; 2010; $135 plus shipping and handling (hardbound).

This unusual book by Nizam Peters, an active and long-standing participant in many aspects of the diamond industry, is a wealth of information about almost everything related to the evaluation of rough gem diamonds, to diamond imperfections, through cutting the finished product-everything, that is, except what we traditionally consider as inclusions. That said, Peters is quite clear in his introduction (p. 1), telling us that "inclusions manifest themselves in the form of colorless to dark or white pinpoints, fractures, and cleavages," and that these may be the result of "conditions such as heat, pressure, temperature changes" as well as mineralogical impurities and the direct impact of man. Thus, Diamond Inclusions does not exclusively treat simple mineralogical or multiphase inclusions but also the characteristics of stored stress, feathers, radiation stains, cutting imperfections, bruises, twin planes, and so on, some of which can even be classified as external rather than internal features. It is profusely illustrated and for much of its 208 pages is essentially a photo-atlas.

Diamond Inclusions begins with a short introduction and a table of contents. Interestingly, the table of contents begins with a short section called "External Features," an outline of sorts that breaks these features down into four groups. Group one consists of features of natural origin. These are covered in Chapters 1-4 and include "naturals," growth markings, radiation stains, external "grainings," twinning lines, knots, cavities, pits, nicks, surface feathers, and cleavage and fractures close to the surface. Group two consists of features that result from the manufacturing process. These are treated in Chapters 5 and 6 and include scratches, wheel marks, cutting lines, extra facets, bearded girdles, rough girdles, and abrasions. Group three, features resulting from wear and tear, are treated in Chapter 7 and include burnt facets, burn marks, and slight percussion marks or bruises. Group four, external features, are impact-derived, such as surface cleavage and fracture breaks; they are described in Chapter 8.

After Chapter 8 in the table of contents we come to a second break that contains another short section or outline, this time a subdivision of internal features. As with external features, they are separated into four groups that are treated in Chapters 9-13. The first group of internal features (Chapter 9) includes crystalline and solid inclusions imbedded in the body of the diamond. Chapter 10 discusses the second group of internal inclusions, those "that existed within and around the formation of the crystal." Group-three internal features covers structural defects formed during and after the crystallization process including fracture and cleavage feathers, colored feathers, color banding and zoning, and stress and strain. The fourth group is covered in Chapter 13 and treats those features derived from the manufacturing process and excessive wear and tear. These include bearded and rough girdles and percussion marks and bruises.

Chapters 14 and 15 are clearly the most important in the book. They are unusually insightful and particularly well illustrated. Chapter 14 describes five gem diamonds with respect to their flaws and how these are identified and handled by the cutter. Chapter 15 contains five sections, each related to one aspect of inclusions in the production of finished stones. These include planning the rough in relation to shape and inclusions, sawing the rough with consideration to inclusions, bruting the rough, and cutting and polishing the rough with regard to inclusions. The book closes rather abruptly and does not contain an index.

I must admit that my initial impressions of Diamond Inclusions were not good, for I simply could not find photographs similar to those so abundantly presented in other, more familiar gemstone-inclusion books. It quickly became clear, however, that this was an apples and oranges situation. Peters presents as inclusions a broader array of things, most of which many of us might consider imperfections rather than inclusions. In fact, the book would have been far better titled "Imperfections in Gem Diamonds." That said, this volume gives insights into the consideration and preparation of stones for the diamond trade that I have not seen elsewhere, and that alone makes it an expensive yet quite worthwhile addition to any gemstone library. My only real criticism is with some of the photographs. Even with the generally quite good captions and marking arrows, in some it is difficult to see exactly what is being illustrated. Some features are too tiny; others seem slightly out of focus. Most, however, are good illustrations that clearly depict the feature being described. I like the book, learned a great deal about gem diamonds, and recommend it to anyone contemplating faceting as a hobby or gemology as a career.

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