Book Review: Gems & Crystals: From One of the World’s Great Collections
This volume is a pleasing combination of coffee-table book, reference book, and guide to a museum collection. It is the 25th anniversary revised edition of the authors’ Gems and Crystals: From the American Museum of Natural History (1990). There is a certain sense of continuity conveyed by having the same authors still working in the field adding to the collection and knowledge base.
The introduction details the notable acquisitions, sponsors, and curators over the years. It all started with the collection assembled by George Frederick Kunz in 1889, financed by John Pierpont Morgan. The department was expanded in the 1970s and renamed the Department of Mineral Science, and in 1995 it became the Department of Earth and Planetary Sciences, which includes minerals, gems, and meteorites. Of the 110,000 minerals and 4,500 gems total, 1,800 are on display in the Morgan Hall of Gems and 2,600 in the Guggenheim Hall of Minerals. A much larger percentage of the gems are on display because they tend to be more visually interesting. The stored collections, however, are a tremendous resource for scientific data gathering.
Part One, “The World of Gems,” gives a very brief history of gems, highlighting the fact that the use of stones for personal adornment can be traced to 25,000 BCE. Through archeological findings and historical texts, it has been determined that there was early interest in the scientific properties of gemstones and not just their beauty or use as amulets. It goes on to describe very basic crystallography concepts and physical properties such as pleochroism and fluorescence, using well-known gems as examples. The writing is clear and not overly technical. Formation and quality factors are briefly addressed. The sections on synthetics, simulants, and enhancements are also brief and do not cover the myriad topics within.
Part Two, “Gallery of Gems & Crystals,” represents the bulk of the book and delves into the details of specific gemstones. It starts with the most commercially significant and well-known: diamond, corundum, and beryl. The format includes a small information box of properties and sections on history and lore, sources, value factors, and specific examples in the AMNH collection. The accompanying photos show the range of colors and phenomena, rough and jewelry examples, historical illustrations, and specimens from the museum.
The section on diamonds includes updates since the 1990 edition for new mining areas, the advent of the Kimberley Process, and synthetic diamonds production by the CVD method. But it neglects to indicate that high-pressure methods are still widely used and have been optimized. Since synthetic diamonds are a hot topic for consumers, it would have been helpful to mention the colors and sizes now attainable. Irradiation is mentioned, but not multistage treatments with irradiation plus HPHT treatment.
In the corundum section, when discussing the benefits of heat treatment, the authors quip, “We could heat the Star of India [the museum’s most famous gem, a 563.35 ct gem-quality star star sapphire] and create a fabulous blue cabochon—perish the thought!” Seasoned gemologists will pick up on the inconsistencies related to padparadscha sapphire—described as “orange” on p. 37 but referred to five pages later as pink-orange and orangy pink (though the famous 100 ct Sri Lankan example shown does look too orangy). And even though there are numerous treatment processes for corundum, only heat treatment is mentioned.
Paraíba tourmaline is given short shrift, only noted as a highly valued blue-green color variety but not highlighted as a recent find, with unique coloration and limited sources. Most disappointingly, it is not illustrated. Perhaps there have been no donations of this fabulously expensive gemstone? There is an interesting comment on the pyroelectric effect that causes the tourmalines in the AMNH collection to attract dust under the heat of the display lights, something that observant museum-goers would notice.
Although the sections are brief, there are interesting tidbits to spark the reader’s interest and understanding: for instance, the observation that treated zircon was commercially available and accepted as early as the 1920s, or that turquoise is the most widely imitated and treated of all gems.
The chapter on jade does skillfully distinguishes nephrite, jadeite, and omphacite, highlighting the huge boulder on display at the museum.
In the section on organic gems, pearls, coral, amber, and jet are covered. The pearl section is a bit brief, considering what is widely available to consumers. Only saltwater pearls are mentioned as cultured, overlooking the enormous significance of freshwater cultured pearls made by bead, tissue nucleation, and other rapidly evolving techniques. Other pearl types that would be of great interest to amateurs, such as conch or clam pearls, are not mentioned.
In the last section, on rare and unusual and ornamental materials, the authors acknowledge their own biases in ranking the gems in descending order of quality. Zoisite has been given just one paragraph and an illustration of a rough crystal. Tanzanite has become so mainstream that it need not be relegated to the “rare and unusual” section.
The book ends with a glossary and an annotated reading list. I heartily agree with the list of 25 books, journals, and websites, as it resembles my own core collection.
A good balance is struck between illustrations of rough, exemplary crystal specimens, faceted specimens, and historical illustrations and jewelry. The biggest disappointment in this book is the quality of the photos. The Van Pelts are legends, but the quality of film photography from 1990 cannot compete with quality of digital photography today. That, coupled with the difference in technology of color reproduction and printing, leaves some photos lacking depth or brilliance. They are simply not up to contemporary expectations.
This book goes well beyond its purpose as an introduction to the museum’s collections and a basic primer on the geology of gemstones as well as the jewelry arts. It is eminently readable and draws the reader into the fascinating world of gemology. It would be useful in a professional environment where one could use the information in the “Historic Notes” and “Legends and Lore” sections to add color to a presentation. The “Evaluation” section serves as basic guidance and a starting point for budding collectors. Some information in “Occurrences” is not up to date, which is understandable given that colored stone mining sites tend to be small and can shift within months. Nevertheless, this book stands on its own as a reference book or—if one is fortunate enough to visit the AMNH in New York—a wonderfully readable guide to the museum’s collection.