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Geology of Gems
Rocks & Minerals
Geology of Gems is the culmination of a rather massive project that spans more years than many of those involved with its publication care to remember. It is the product of a lifetime of professional evaluation of optical quartz, gemstone, and related deposits by well-known Russian geologist Eugenii Yakovlevich Kievlenko (1923-2000). Several years ago I, along with John White of Kustos, was asked to edit the very preliminary English translation of this massive work. As I began to plow through the text, it was evident that the job was far too rigorous and complex for me. Both Mr. White and I reluctantly withdrew from the project. The task was then undertaken by Dr. Art Soregaroli, who has done a remarkable job of carrying a difficult, once poorly translated text into a quite useable reference that, for some species, is the most concise and complete English description of their geological occurrences.
The book begins with an important foreword to the English edition, acknowledgments, and a general foreword. These are followed by chapter 1, a discussion of general gemstone data including a classification based in part on price index, jewels, and synthetics. Chapters 2-19 describe eighteen specific traditional gemstones or families, beginning with corundum and ending with rhodonite. For each there is a general discussion followed by descriptions of occurrences of each genetic type. For example, corundum gems are described as magmatic, pegmatite, contact-metasomatic, metamorphic, and placer deposits. There are subheadings under several deposit types for many species; for the beryl gems, emerald and aquamarine and other beryl deposits are treated separately. Although not covered individually in the text, data for twenty-eight lesser or nontraditional gemstones, such as andalusite, brazilianite, and kyanite, are tabulated in chapter 1. Chapter 20 consists of a synthesis of genetic data that presents an interesting discussion of regularity and spatial distribution of different major types of gemstone occurrences. The text closes with a listing of abbreviations and references.
The final section of the book is a "Gems Photo Gallery" in which each gemstone to which a chapter is devoted is illustrated by superb color photographs of both specimens and finished stones. Most of the 129 photos are by Jeff Scovil or Michael Leibov. Many species are represented by fine Russian specimens. In addition, the book contains 127 maps and cross sections that illustrate critical deposit characteristics and distributions.
It is easy to find fault with books of this sort. There is always a favorite deposit that was not discussed or some odd geologic circumstance about which to quibble. The English translation might not have exactly the same emphasis or meaning as the original Russian. However, there are several reasonable things that would have made the book better. The color illustrations should have been appropriately placed within the text rather than clumped at the end of the book, although this certainly would have added significantly to production costs. Four pages of ads follow the photo gallery and, to this reader, detract from the scholarly importance (and appearance) of the work. There is no index--a serious matter to those wishing to use the book as a technical reference. There is no chapter devoted to what is arguably the most important gemstone, diamond. Although integrated into the initial chapter, it is scarcely mentioned again. Finally, and by far the most serious criticism, many of the references cited in the text are not in the list of references, making it impossible to gather additional information from these sources. Still, if I were asked to recommend a single general text on the geologic occurrence of gemstones, this would be the book. I have already used it for the Connoisseur's Choice column in this magazine and will continue to do so. I recommend it as informative reading from a general interest perspective and a good addition to any mineralogical or gemological library.
-Robert B. Cook
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The Mineralogical Record, Mar/Apr 2005
Evgenii Yakovlevich Kievlenko (1923-2000) was a distinguished exploration geologist and gemologist who, among other achievements in industry, furthered the economic development of several Russian deposits of piezoelectric quartz crystals and "Iceland spar" calcite. In the late 1960's, upon joining a Soviet government team charged with identifying and evaluating gemstone deposits in the U.S.S.R, he began compiling data for the work under review here. Although Kievlenko wrote in Russian, the first good news is that Geology of Gems is nearly free of the sort of linguistic cramp-ups which have often marred English translations of Russian texts in the past; we owe thanks for a job extremely well done to the six translators and no doubt numerous copyeditors. Compliments are due, too, to the seven expert photographers whose works appear in the beautiful "Photo Gallery" at the end of the book; to Irina Fashchevskaya, for her fine layout work; and to the chief editor for the Englishing project, Dr. Art Soregaroli. This book is a careful production, as sturdy in its erudition as in its physical packaging, and something of a breakthrough in its way of combining the two title-concepts, Geology and Gems.
This is to say that while most pretty books about gemstones are aimed at readers or browsers whose interests do not necessarily run to formal geology, this book's ideal reader is required to be geologically literate, since, to quote from the Foreword, "The main purpose . . . is to acquaint professional geologists with characteristic features of geological structure and geological settings of [gemstone deposits], thereby ensuring well-directed prospecting for such deposits." But even the reader who is not (as Kievlenko was) a professional prospector will find useful the book's wealth of geological data concerning many "hot" gem-crystal localities of today. Where have you seen, anywhere else, many thousands of words and dozens of geologic maps and line drawings in explication of places like Rangkul or Kukhi-lal, Tajikistan; Malkhane, Chita Oblast, Siberia; Volodarsk-Volyn', Ukraine; or Darai-Pech, Afghanistan? Of course the book also treats, as other books do, of the geology of Brazilian, African, North American etc. gem fields, but it is a virtually unique reference work on many a gem-crystal site in central Asia. Magisterial, dense, educational, Geology of Gems is capable, too, of bringing the science behind your specimen labels to life in a flash, like lightning over the steppes.
After a 24-page presentation of "General Data on Gems," 18 chapters examine individual gem-substances. Really, though, "decorative stones," not "gems," is the operative word, since, as the "General Data" chapter announces, the book covers not only gemstone minerals but also ornamental and carving materials, synthetic gems, and organics (amber-although not pearls). A table displays Kievlenko's classification of all these substances by their commercial value, showing the evolution of his value-based system from that of Kluge (1860). Kievlenko's three major divisions, in descending order of value, are "jewelry stones," "jewelry-industrial stones," and "industrial stones." The "jewelry stones," in turn, are ranked in four "orders": first (diamond, ruby, emerald, blue sapphire, alexandrite), second (demantoid, tsavorite, spinel, black opal, tanzanite), third (other-colored sapphires, rubellite, aquamarine, imperial topaz, white and fire opal) and fourth (other beryls, other tourmalines, other garnets, amethyst, citrine). "Jewelry-industrial" and "industrial" materials range down a scale from lazurite, jadeite and nephrite at the top, through charoite, rhodonite, jasper and petrified wood, to items like "aventurine quartzite," "ophicalcite (serpentine/ calcite)" and "agalmatolite (pyrophyllite/ talc)" although, perhaps mercifully, the last three which merit separate chapters in the parade of chapters to follow are malachite, chalcedony and rhodonite.
Two more interesting tables in "General Data on Gems" deserve mention. One shows average per-carat prices (in U.S. dollars, 1987-1992) of the gem materials; the other lists 28 "non-traditional gemstones," amblygonite to willemite, with generous mineralogical, optical and geological/genetic data. Surveying this latter table, one wishes (if one is a mineral collector) that certain gem materials of "non-traditional" type, listed here, had been awarded chapters of their own: benitoite, brazilianite, euclase, sinhalite, or even sphalerite might justly have claimed more text-space (we think, if we are mineral collectors) than chalcedony or amber, each of which gets a large chapter. Another surprise, and a disappointment, is that there is no chapter on diamond to head up the parade. The English Editor says in his Foreword that this is because diamonds always have "received special and isolated attention in Russia"; we may not quite understand this, but it means that we must settle in this book for just a few diamond-factoids (e.g. the retail price per carat, for a fine 3 to 5-carat diamond, tops out at $41,500).
On, anyway, to chapters #2 (corundum) through #19 (rhodonite), which treat individual "decorative stones." Here, as mentioned, Geology rules, and the text takes on a "reference" rather than a "general reading" style, with cascades of authoritative, well organized geological/genetic information for each gem mineral. A typical one of these chapters is organized in two parts: a general discussion of the gemstone in question, with data on crystallography, optical properties, inclusions, the history of its use as a gemstone, and whatever else is of interest; and a section on geological/genetic types of deposits, with appropriate subdivisions (common headings here include magmatic, pegmatitic, greisen, hydrothermal, contact-metasomatic, and placer). There is no attempt to furnish full data for every major deposit of each type for each major species; rather there is, as already mentioned, an emphasis on detailed presentations of the geology of ex-Soviet and central Asian occurrences. For topaz, for example, the subheading "pegmatitic deposits" sets up several pages on the Volodarsk-Volyn', Ukraine pegmatite, several more on the Ural and East Siberian pegmatites, almost a whole page for the Rangkul, Tajikistan pegmatite field, and just two pages giving about a paragraph each to many U.S. and Brazilian occurrences. Then there are similar treatments, in similar proportions, for "greisen" and "hydrothermal" and "placer" topaz occurrences, taking the reader from Schneckenstein to Teofilo Otoni. Typically, too, there is a sprawling table showing the geological/ genetic classification of topaz deposits; two clear, uncluttered geological sketch-maps for the Ukraine occurrence (one for the pegmatite field, one for the eluvial placers); one sketch each for two of the Russian occurrences; and one sketch each for geological structures in Minas Gerais and the Thomas Range, Utah. Coverage of this sort seems continually to anticipate what Western readers, especially, will want most to know, both about where and how gem topaz crystals occur.
A final, summary chapter offers about 15 pages of generalization about geologic environments for gemstone species, with another big table and with sketch maps showing locations of major gemstone deposits on each continent. The "References" list that follows shows an amazing 902 titles-at least as many English, German and French (combined) titles as Russian.
Then comes our rich dessert: 30 full-color pages with uniformly fine photographs of all the book's subject-substances . . . and the ratio of crystal specimens to cut gems, slabs, carvings, etc. here is higher than you might expect. About half of the photos are by Russian photographers, and show specimens now in Russia, hence probably unfamiliar to most Western readers. Included among these images is a photo of the Grand Imperial crown of the Romanovs, topped by a 398.72-carat red spinel-the photo by Alexei Sverdlov. The other contributing photographers are Anatolii Akimov, Mikhail Bogomolov, Michael Leibov, Erica and Harold Van Pelt, Jeff Scovil and Wendell Wilson.
At the very end of the book are three pages of commercial ads for American dealers and one page for Russia's "Mineralogical Almanac," necessary, presumably, to help finance publication. What is unfortunately missing is a good, thorough index for the text.
Geology of Gems is a winner, a major work-and it can fit equally well in the Gem or Geology section of your reference library.
-Thomas P. Moore
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Mineral News
The English edition of this extensive work is now available after several years of painstaking translation. Having had some modest experience with deciphering and stylizing translated Russian works, I can attest to the difficulty of the task. Art Soregaroli, however, has done an excellent job in turning this complex, technical book into readable and understandable English. Although he makes reference to some arbitrary selections made when attempting to resolve conflicting locality names and terminology, his hard work is readily apparent.
This large volume attempts to provide a detailed geological and environmental framework for the genesis of gem deposits, intend for use in further exploration and discovery of new deposits. Although its scope is worldwide, much of the data is derived from the extensive studies conducted by scientists in the huge former U.S.S.R. territories. It opens with the customary forwards, acknowledgements and a chapter of general data on gems, briefly describing a somewhat subjective, value-based classification, along with sections on jewels, the jewelry and ornamental stone industries, and a brief discussion of synthetics.
The bulk of the text is divided into eighteen (18) chapters, each devoted to a single gemstone. Each chapter provides general information and further subdivides geological and genetic types of deposits for the selected gem in question. In the “Corundum” chapter, for example, the author devotes over thirty pages to 1) magmatic deposits (basalt and alkaline basalt extrusions, plus alkaline basic lamprophyres), 2) pegmatite deposits, 3) contact metasomatic deposits (endoskarnes in marbles and micaceous anorthosites in mafic and ultramafic rocks), 4) metamorphic deposits, and 5) placer deposits. In addition to the detailed discussions of the deposits in a variety of countries, many specific localities are accompanied by geological structure diagrams or cross sections. Exhausting stuff!
While this is a work of remarkable geologic detail, I would take exception to the definition and the choice of gem materials that are so thoroughly described. The author patiently builds his selection on the criteria of aesthetic quality and durability. The mix of traditional precious stones (e.g. corundum), semi-precious stones (e.g. tourmaline, generic garnet), and decorative lapidary materials (e.g. charoite, rhodonite, chalcedony) appears too wide a definition of “gem”, and the choices are even more incongruous as they omit diamond (intentionally) as a selection.
As somewhat of a mineralogical purist, I believe that describing jadeite as a pyroxene “somewhere in the diopside-aegirine-jadeite series” lacks precision. The mineral jadeite is jadeite, nothing else. The issue is further complicated by the author’s additional selection of “nephrite” as another gem material, further muddying the waters. This lack of precision only fuels the wildly heated debate in the gem trade today about what is loosely termed “jade” (a gemstone terminology, not a mineralogical one!). There is jadeite, and then there is everything else to my simplistic mind. But, I digress; the “what is jade” war will have to be fought elsewhere, outside of these pages.
Chapter twenty summarizes the various deposit types so meticulously developed in the preceding chapters, and it is amply illustrated with a variety of charts and diagrams. This is followed by an astounding list of references, citing over 900 different sources that were used in the compilation of the book. Color photographs, lacking in the body of the book, are a thirty-two (32) page add-on in the back to cut production costs. The pictured specimens are exquisitely done by well known mineral photographers Scovil, Leibov, the Van Pelts etc. Four pages of color advertisements (a little tacky, but an effective way to garner up-front funding) close out the book.
This is an unusual tome for your library, perhaps best suited for the advanced field collector or prospector looking to uncover new gem deposits via a methodical comparison to the monumental amount of data presented in this 400+ page book! While largely based on the observed geological deposits of various gemstones and gem materials found in the vast former U.S.S.R. territories, advanced field collectors will find some extraordinarily detailed information here.
-Tony Nikischer
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