This edition has been completely revised to cover the latest methods of gem enhancement and identification, as well as the most up-to-date test instruments and laboratory techniques.

Gemmology is a text for students preparing for the Gemmological Association's Preliminary and Diploma examinations. The book is more expansive and up-to-date than the author's earlier book, Beginner's Guide to Gemmology. The book deals with the practical and theoretical sides of gemmology. Tracing the background and science of gemmology, the book covers the gem material, geological formation, and occurrence of gemstones on the earth. The composition of gemstones from the atoms, elements, molecules, and compounds comprising them is analyzed, and the relationship between chemical composition and durability of the stone is explained. The basics of crystallography is mentioned as a tool toward understanding gemmology after which cleavage, parting, and fracture are done. A gemstone's durability and hardness and how the latter influences engineering tests and the mining techniques are compared. An important test technique to identify unmounted stones is the measure of specific gravity using displacement measurement methods and hydrostatic methods. After more descriptive details are given in identification of gemstones, whether these are synthetic or simulants, through a comprehensive explanation of the materials found in these other gemstones, the fashioning, through shaping or polishing, of gemstones is explained. Emphasis is given on the critical angle in which light rays pass in different rock densities, and then the cutting styles, gemstone polishing, and grading are discussed. Students studying for the Gemmological Association's Preliminary and Diploma examinations, jewelers, lapidarists, and diamond cutters, as well as those engaged in the hobby of gemmology, will find this book helpful and full of information toward their endeavors and hobbies.

This book provides a lucid introduction to the basics of gemmology. It familiarizes archaeologists, art historians and conservators with the science of gemstones and allows them to understand the basic concepts of their provenance, typology and treatments. Which are the main types of gems? What treatments can be applied? How does one analyse gems? How can gems contribute to archaeometrical research? This volume is written by four experts in the fields of gemmology and archaeometry and addresses both students who need an introduction to this field and professionals who want to refresh their knowledge of the topic. This work is part of a series of introductory texts that deal with a broad range of materials-related topics in archaeometry.

Beginner's Guide to Gemmology presents the profiles of the principal gem materials. This book discusses the interesting characteristics of gemstones as the growing consumer market jewelry resulted in increased sales of gem testing instruments. Organized into 12 chapters, this book begins with an overview of the development of the science of gemmology. This text then explains the fundamental qualities necessary in a gem, including color, hardness, specific gravity, crystallography, refractive index, pleochroism, critical angle, luminescence, and absorption spectra. Other chapters consider the organic gem materials, including amber, ivory, coral, tortoiseshell, jet, ebony, and pearl. This book discusses as well the various methods used in the production of man-made gemstones and the commercial use in gem testing. The final chapter deals with the composition of synthetic gemstones. This book is a valuable resource for gemmologists and jewelers. Students who intend to become a qualified gemologist will also find this book extremely useful.

Although suitable for readers of all levels of understanding, 'Practical Gemmology' is specifically tailored to provide the information and diagrams necessary for the successful completion of diploma examinations and is an invaluable tool for gemmology students.

A concise, systematic, yet comprehensive ``textbook'' treatment of the science. Examines origin, chemistry, crystallography, physical properties, and optical properties of gemstones, and discusses methods and instruments used to determine these properties. Highlights recent advances and important contributions; explores new methods of study and determination, crystal structures, causes of color, new gem minerals, new methods of gem synthesis, manufactured gems, chemical compounds used as substitutes, and imitations and simulations. Includes 12 full color plates, 350 halftones and line drawings, and a Gem Index that lists commonly sought characteristics along with page number references.