The zidentification of ivory has always been difficult for object conservators, partly because ivory used in objects can come from a variety of sources besides elephant. Hippopotamus, walrus, and sperm whale are the ones a conservator is most likely to encounter. Ethnographic conservators may find ivory from these and other more esoteric sources. In addition, there are several ivory substitutes that can be either natural or manmade.

Additional difficulty is presented when ivory is fashioned into an artifact. One can easily identify an elephant tusk when complete and unaltered, but once the gross morphological characteristics have been modified or removed through carving, it can be difficult to distinguish from ivory substitutes. Even if the material is clearly ivory—that is, it comes from mammalian teeth or tusks—the source can be difficult to determine with certainty.

The standard text for aid in identifying ivory has been T. K. Penniman's Pictures of Ivory and Other Animal Teeth, Bone, and Antler (1952). Since this book was rather obscurely published by the Pitt Rivers Museum in England, not many Americans are familiar with it. Its approach is fairly basic, and conservators usually rely mainly on the excellent photographs of cross sections for tentative identifications. Two books published within the last two years will greatly help conservators in examining ivory. Both present considerably more information on the structure and diagnostic characteristics of different kinds of ivory and provide some simple tests that can be used to aid identification. More important, they provide a methodology for approaching the identification of these materials. Neither is intended for conservators, but both are valuable additions to the literature and will be useful references.

The scope of Krzyszkowska's Ivory and Related Materials: An Illustrated Guide is limited to ivory used in the ancient Aegean world (elephant, hippopotamus, and wart hog) and to ivory substitutes such as bone and antler. The book is designed for archaeologists working on material from the ancient Aegean. As a result, all references and illustrations relate to material from that time and part of the world, but this should not deter other readers. The information presented holds true for all ivory of the types described regardless of when or where it was fashioned into objects. The importance of the book lies in the clear description of different kinds of ivory and the discussion of criteria and procedures for identifying these materials once they have been modified into objects.

The first two chapters are introductory. Chapter 1 deals with methods and equipment and sets out the basic problems encountered in identifying ivory and its substitutes. Chapter 2 discusses the potential sources of these materials for the people of the ancient Mediterranean.

Chapters 3 and 4 form the heart of the book and will be of most interest to conservators. The author's premise is that in order to distinguish between ivory and its substitutes once they have been modified into artifacts, it is “important to have a clear understanding of the principle features and properties of these materials in their unworked state.” These features and properties are clearly set forth in chapter 3 for ivory and boar's tusk and in chapter 4 for bone and antler. The morphological features and structures of each material are clearly discussed. These discussions are not, and were not intended to be, comprehensive expositions. Rather, they are limited to the aspects of these materials most relevant for identification purposes. They were also purposely kept nontechnical for the nonexpert reader for whom the book is intended.

In chapter 5, the author sets out a method for approaching the identification of ivory and its substitutes. The diagnostic criteria presented in chapters 3 and 4 have been worked into a methodology that the reader can use to distinguish between elephant and hippopotamus ivory, bone, antler, and boar's tusk. The author provides a logical step–by–step procedure and carefully discusses the pitfalls that may confuse identification.

The text is augmented by short appendices covering other animal products; inorganic substitutes for ivory; the care and storage of ivory and related materials; and reference collections. Each of these topics is dealt with in a cursory manner, each could easily be the subject of an entire book.

The book pulls together a wealth of information from a variety of sources and presents it in a clear and readable form. Each section is copiously illustrated with excellent line drawings, diagrams, and photographs. While the detail on some of the photographs could be clearer and sharper, they are still extremely valuable.

My only criticism is of the book's binding. Considering how much the book will be used as a reference, it is a pity that it was not bound better. After reading my book once and leafing through it in writing this review, the last signature is already pulling away from the spine. In spite of this, the book will be a valuable addition to the library of anyone who handles artifacts made of ivory and related materials. It should be a must for every archaeological excavation's library.

Espinoza and Mann's Identification Guide for Ivory and Ivory Substitutes aims to “offer wildlife law enforcement officers, scientists, and managers a tentative visual means of distinguishing legal from illegal ivory.” It gives the object conservator visual and nondestructive means of distinguishing between ivory and substitutes. As with the Krzyszkowska book, this volume deals with some forms of ivory the average conservator is unlikely to encounter, such as mammoth ivory. It is more comprehensive that the Krzyszkowska book in that it considers a wider range of ivory: elephant and mammoth, walrus, sperm whale and killer whale, narwhal, hippopotamus, and warthog. The ivory substitutes covered are bone, shell, helmeted hornbill, vegetable ivory, and those manufactured from various resins.

The book begins with a section on the structure of ivory, describing the various components of a tusk or tooth. Two very useful tables follow. Table 1 is a flow chart for making preliminary distinctions between different kinds of ivory and ivory substitutes based on diagnostic characteristics specific to each material. Table 2 is a summary of the class characteristics of various ivories that are discussed in greater detail in the following sections. The first step in the flow chart is to examine the unknown material under ultraviolet light, but neither table tells what results to expect for ivory or for substitutes. Anyone who is experienced in looking at ivory under ultraviolet light knows that it fluoresces blue–white, but this fact is not explicitly stated until page 26 in the section dealing with manufactured ivory substitutes. This is important information, being the primary means of distinguishing ivory from substitutes, and should be included in these tables, as it is in table 3 for ivory substitutes.

The rest of the book consists of sections on each form of ivory, clearly detailing the structure and diagnostic characteristics specific to that material. The section on elephant and mammoth presents an interesting new means of distinguishing between the two by measuring the angle of the Schreger lines, commonly referred to as engine turnings or cross hatchings on a cross section. This test is nondestructive and requires only a photocopy machine and a protractor to make the determination. Each section includes a good photograph of a cross section of the unworked material discussed, clearly demarcating its various components. This is little or no discussion of the appearance and characteristics of the surface. As a result, these discussions are of less use to the conservator who frequently does not have a cross section available for examination.

The final section discusses ivory substitutes. Table 3 is a summary of the characteristics of various substitutes, including the ultraviolet characteristics each display. With this guide it is relatively easy to distinguish an ivory substitute, but, especially in the case of manufactured substitutes, it may require FTIR to pinpoint the exact material. Table 4 provides very useful information for the conservator by identifying the trade names, composition, and manufacturers of various common manufactured ivory substitutes.

The book includes a glossary, a comprehensive bibliography, and two appendices. The first two will be of use to the conservator, while the appendices merely summarize the flow chart of table 1 and list the equipment needed for the Schreger angle test.

Until now, clear information on the identification of ivory has been lacking. These two books provide new information on this topic, although neither is intended for the conservator. The Espinoza and Mann book is probably of slightly less use to the object conservator than the Krzyszkowska book in that it deals with cross sections of unmodified teeth and tusks and is less concerned with artifacts. Surface characteristics are dealt with only superficially, and no photographs are given of worked ivory. It will be of greater use to anthropological and natural history conservators, who are more likely to encounter the more esoteric forms of ivory described by Espinoza and Mann in a less modified form. Even so, it is a useful addition to the conservation literature. These two books provide conservation with important new reference sources, and both should be in the object conservator's library.