Bone, Ivory, and Horn: Identifying Natural Materials

Book Review by Eric J. Hoffman


   Michael Locke. Schiffer Publishing, 2013. 320 pp, numerous color & b/w illus, hardbound, 10-1/2 x 7-/12 inches. $45.


    The age of plastics began in the 1870s; it often seems that nearly everything today is made from that ubiquitous material. But it wasn’t so long ago that everyday objects—both the practical and the decorative—were made individually by skilled craftsmen from natural materials such as bone, ivory, horn, antler, and wood. This book, written by a scientist (an insect biologist) who is also a lapidary and antiquarian, will teach you how to identify natural materials and how to tell bone from ivory, horn from tortoiseshell, and old from new.

   The author’s scientific background clearly shows itself in the level of technical detail and his precise scientific terminology, some of it in Latin. He carefully describes where bones, horn, and shell come from, how they form, and how they evolved to solve particular structural problems in the host animal. This background sets the stage for clues the reader can use to identify the material. Dr. Locke describes the three kinds of bone and why antler is tougher than bone (and so reserved for applications such as handles for knives and corkscrews). 

   Ivory receives a particularly thorough discussion. You may already be familiar with the Schreger pattern in elephant ivory. Schreger angles allow us to differentiate between ivory from modern elephants (now illegal) and that from extinct mammoths (legal). These angles can even help differentiate Indian from African elephant ivory. Elephant ivory is the commonest in commercial use (“Rodgers cutlery was probably the world’s largest consumer of ivory in the nineteenth century.”). He shows the fascinating ivory “pearls” that form in certain tusks. But the other “ivories”—from animals, birds such as the helmeted hornbill, and even vegetable ivory—are thoroughly discussed as well. Elephant ivory is of course today a controversial subject; the author treats it with sensitivity.

   The technical scientific text is leavened with interesting discussions of the mythology surrounding rhino horn, narwhal, “unicorns,” and so on. Still, the reader must be prepared for occasional sentences like this one: “The main inorganic component [of ivory] is hydroxylated calcium phosphate, hydroxyapatite, (Ca3OH)2(PO4)6(Ca4) that has carbonate substituted to varying degrees for either the phosphate or hydroxyl sites to become the mineral Dahllite.” Fortunately there is an extensive glossary.

   Moving on to keratin (horn, tortoiseshell, etc.), he describes why far fewer of these objects survive (as compared with ivory, for example). The main destroyers of keratin are larder beetles and moth larvae (in fact beetle bite marks provide a reliable antiquarian indicator). Leather, vellum, shagreen, baleen, rhinoceros horn, feathers, jet and more are each discussed in turn. There is, however, little discussion of wood.

   The final one-third of the book discusses artifacts and antiques made from all these natural materials. This section is extensively illustrated with examples, most apparently from Dr. Locke’s own collection. It’s fun to try to figure out what some of these quaint objects were used for, before he tells you. He also gives practical information on repairing and conserving these artifacts.

   The author has clearly put an enormous amount of work into this book and in maintaining its scientific accuracy. Unfortunately, the editors did not support him with the same care. There are occasional undefined or missing abbreviations, missing prefixes on some abbreviations (making in one case a factor of a million difference), and other mistakes dealing with units. Some figures are missing or misnumbered, or the text points to the wrong figure. Some figures are too small to see the necessary detail. Typos are sprinkled throughout, along with an occasional missing sentence fragment. This makes reading such a technical book a bit more challenging, but in this case it is worth the extra effort for anyone interested in artifacts made from these materials.


Copyright © 2014 by Eric J. Hoffman (Home Page)

Originally published in ASJRA Newsletter, August 2014