This very recommendable book is a very comprehensive guide to the industry of diamonds and contains historical as well as very technical guides to this fascinating world. The edition I’m reviewing here is the Second Edition from 1978 (the first was published in 1970). Regardless of the edition, some terms will necessarily be outdated by today’s standards, a flagrant example being in the names of the color grading (the D-Z grading scale widely used today was established by GIA in the 1950s, but was apparently not a global standard by the time this book was printed).
The first introductory chapter is dedicated to the history of diamonds, from antiquity through Tavernier’s travels of the 17th century, until our days. This is a very interesting chapter which touches very far-apart subjects such as diamonds in literature, and the use of diamonds before they were considered as gems: as a medicine, a poison, as well as a source of magic. Also the qualities and attributes of diamonds are treated and we are introduced to synthetics and simulants. Bruton then begins to explain how diamonds were at a later time considered in the creation of jewellery. Interestingly, the Hungarian Royal Court possessed one of the earliest important jewels (in Western civilization?) set with diamonds (in this case still uncut): the Holy Crown of Hungary, of the 11th century CE. The chapter ends with brief paragraphs about the brilliant cut and the diamond trading market as being based on trust.
The next five chapters deal with mines and the process of prospecting and extracting diamonds. We are introduced to the countries which were most relevant at an early stage in the diamond mining industry: India, Brazil, and Africa, with focus on South Africa. In the latter country, the first pipe mines (geological formations, resulting from volcanic activity) were found and exploited. We are introduced to perhaps the most famous mine in the world, the Kimberley Mine, named after the town in which it is located. Here a key role was played by the De Beers Mining Co., which was to become one of the most influential and significant players in the diamond mining industry. It must be said here that the series of photographs (both in black-and-white and color) of the mines and the African landscapes included in the book are breathtaking. Other African countries are described such as the Belgian Congo (today the Democratic Republic of Congo), Lesotho and Botswana. Also countries in other continents: Australia, Canada and Russia.
An interesting chapter follows on mining and recovery methods, from antiquity to modern times. Here we are introduced to concepts such as the use of the Cradle, the Yankee Baby and the Picking Table in recovering diamonds and the crumbling sides problem in mining (the soft earth and rocks were continuously crumbling, attempts were made to cut the rock formations into layers of concentric circles.) A chapter is dedicated to how the diamonds are extracted from the rock formations and debris coming from the mines. Apparently there were as many as ten stages the rock formations and earth went though (from primary milling to hand sorting) before the diamonds could actually be extracted and processed. Finally, diamond prospecting is described, the earliest stage in the diamond industry chain, but a crucial one, as those who knew how and where to find the precious stones, the prospectors and adventurers, were the ones who would reap the huge benefits.
Next Bruton explains how the diamond market works, or rather worked in the 1970s, with an explanation of the central role of the Central Selling Organisation, CSO. The CSO (now the Diamond Trading Company, DTC) controlled most of the world’s diamond trade. He explains how prices are controlled and the gems are sold on the market through clubs and bourses. There is a very interesting picture of the Diamond Bourse in Antwerp as it looked in those days, with a very large number of buyers, sellers and brokers sitting at tables, inspecting the diamonds in natural light allowed in by huge windows.
The book now becomes very technical, with several chapters concentrating on the techniques for the cutting and polishing of diamonds. In the history of diamond cutting, Bruton explains that in Europe the techniques originated in Venice, then spread to Bruges and Paris. In the fifteenth century, diamond cutting first appeared in Antwerp, who was to become the diamond capital of the world. The different types of cuts (Point, Table, Rose, Mazarin) and their history are described and illustrated. The illustrations notably are very detailed and accurate. We gain an understanding of the process of grading polished stones for color, clarity and cut. There are many pictures of the different clarity grades for example, but it is difficult to distinguish between them purely based on the pictures, as they are in black-and-white and of not very good resolution. The drawings next to the pictures do help, but photography was just not advanced enough in the 1970s to allow any proper illustration of color and clarity grades. Even today, with 360° diamond images of superb quality, a buyer still wants to inspect gems with a loupe in natural daylight before making a decision on the quality of the stone.
For the mineralogical enthusiasts, Bruton moves on to the geological aspects of diamond mining. Kimberlite pipes are explained and illustrated in detail. A possible explanation is given as to the reason for the formation of crystallized diamonds in the Earth’s interior. There follows a fascinating chapter on diamond crystals, where the stones are described from a purely mineralogical viewpoint. Depending on the source, a diamond assumes a different type of crystal shape (Octahedron, Hexahedron, Tetrahedron, etc.) and can contain large inclusion, even a diamond inside another diamond. We are taught the physical properties of a diamond: the explanation for its hardness lies in its geometrical structure, a structure in which the atoms form a crystal.
Bruton includes a chapter on synthetic diamonds and artificial coloration, which was in an experimental phase at the time the book was published. De Beers and GE were apparently greatly involved in the early manufacturing of artificial diamonds. There have also been attempts throughout history of deceitfully improving the color of diamonds by using the property of complimentary colors to produce white light. If a stone for example had a slight yellowish color, by applying the complimentary color violet, you could attempt to neutralize the yellow tint. The reverse has also been practiced (and still is today): using irradiation or bombardment (neutron, electron, etc.) to artificially color diamonds, so that they assume a more attractive color, for instance green.
The book ends with an interesting chapter on famous diamonds. Many legendary diamonds are treated here, among which the Cullinan, the Koh-i-Noor, the Great Mogul, the Orloff Diamond (more commonly spelled Orlov today), the Sancy and the Regent. The list is very exhaustive, I counted more than sixty. Appendix 1 and 2 include a list of the world’s largest rough and polished diamonds respectively. The last chapter focuses on identifying diamonds, either by eye or using professional instruments. There are various tests one can perform, the Tilt Test, Breath Test, Sticky test, Water Test, etc. to distinguish a diamond from its simulants (materials with similar gemological characteristics to those of a diamond).
The book includes a handy glossary of terms and a brief guide to grading standards in the appendices.