gemology, reference, dictionaries, gems, Broken Bangle

The sixth edition of this gemological dictionary, revised and updated by the Gemological Institute of America’s staff, assembles more than 4,000 English and foreign words, technical terms and abbreviations encountered in gemological literature and the gem, jewelry and art trades. Its principal coverage extends to colored gemstones and ornamental, decorative and curio stones, with detailed diamond coverage treated separately. Designed as a compact reference for nonspecialists and beginning students, it also serves jewelers and gemologists who need to resolve unfamiliar terminology or clarify relationships between names. Alphabetical entries combine definitions with information on mineral identity, composition, crystal system, color, optical behavior, hardness, specific gravity and sources. Properties shared by a mineral species are generally placed under the species entry, while varieties receive separate property descriptions when their characteristics are sufficiently distinctive. The vocabulary extends beyond mineral names to organic gem materials, synthetic substances, imitations, treatments, lapidary work, jewelry practices, instruments and testing procedures. Entries explain such subjects as selective absorption, adularescence, durability, crystal forms, gemstone proportions and the operation of gemological equipment. Foreign equivalents, historical names, regional expressions, trademarks and obsolete or misleading commercial designations are included so that readers can interpret terminology encountered outside standardized mineralogical usage. Quotation marks identify names judged incorrect or deceptive, while cross-references connect synonyms and related concepts. This distinction is illustrated by the treatment of “African jade” as a misleading name for green grossular garnet. Pronunciation guides and definitions of abbreviations support accessibility, and unfamiliar technical language used within definitions is itself incorporated into the reference system. The dictionary additionally functions as a professional directory through entries on organizations, laboratories, museums, periodicals and gemological titles. Its presentation brings scientific vocabulary together with the language of commerce and craftsmanship, emphasizing accurate identification and clearer communication. Rather than presenting a continuous instructional narrative, the volume supplies interconnected explanations that allow readers to move from a particular name or problem to the underlying material, property or practice.