Gemmology

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.

Here will be found a shortened but complete course in gemmology, following the traditional lines adopted in teaching students at Chelsea Polytechnic in preparation for the Gemmological Association Examinations. This book contains classic material dating back to the 1900s and before. The content has been carefully selected for its interest and relevance to a modern audience.

Gemmological Instruments deals with the developments in diamond grading equipment and gem testing instruments since the publication of the first edition in 1978. These developments include improvements in the versatility and styling of existing instruments such as the reflectivity meter, the composite spectroscope, and the refractometer. It also addresses the criticisms in the first edition and provides a discussion of the advantages and disadvantages of different gem testing equipment. This book is organized into 16 chapters that describe groundbreaking instruments like the thermal conductivity diamond testers and home-constructed items that while innovative have not yet been commercialized. There are also chapters dealing with microphotography and identification of synthetics and stimulants. This book also provides a listing of gemstone constants and characteristic inclusions in natural and synthetic gemstones. This book will be of interest to people interested in equipment for gem testing and diamond grading.

Vols. for July 1964 include Proceedings of the Gemmological Association of Great Britain.

This work covers principles of Raman theory, analysis, instrumentation, and measurement, specifying up-to-the-minute benefits of Raman spectroscopy in a variety of industrial and academic fields, and how to cultivate growth in new disciplines. It contains case studies that illustrate current techniques in data extraction and analysis, as well as over 500 drawings and photographs that clarify and reinforce critical text material. The authors discuss Raman spectra of gases; Raman spectroscopy applied to crystals, applications to gemology, in vivo Raman spectroscopy, applications in forensic science, and collectivity of vibrational modes, among many other topics.