Gems And Gemstones

"Gems and Gemstones" features nearly 300 color images of cut gems, precious and semiprecious stones, gem-quality mineral specimens, and fine jewelry to be unveiled in the new Grainger Hall of Gems at the Field Museum in Chicago.

Simon & Schuster's Guide to Gems and Precious Stones provides both the connoisseur and the casual collector with a compact, easy-to-use volume describing more than 100 rare varieties of minerals whose beauty and mystery have possessed our imaginations from time immemorial. More than 450 brilliant photographs accompany profiles of each gem, covering such aspects as appearance, physical properties -- density, hardness, refraction -- occurrence, and how to judge quality and value. Additional sections describe the process of cutting gemstones and the techniques professional gemologists use to evaluate a stone's weight and optical properties. Detailed and comprehensive, this book is essential for anyone interested in the study of gems and precious stones.

Each gem deposit-whether of primary origin in the parent rocks; or secondary as alluvial placers in valley floors, river gravels, or the sand of oceanic shelves presents an eloquent chronicle of the Earth's life story. It reveals to the expert the prodigious processes which formed the present crust of our planet, of which this volume discloses a small but exciting detail. The materials of the Earth's crust are the rocks. In this book, the author expounds on how they were formed, why they altered, why they became the cradles of precious gemstones, how they are categorized, and how they are now exploited by man. What initiates the growth of gemstones? How do they crystallize? Why do gemstones of the same species, originating from different sources, vary? What causes the occurrence of varieties? Why do diamonds, unlike other precious stones, occur not near the Earth's surface in its crust, but deep down beneath it in the upper mantle? These are only a few of the entrancing subjects discussed in this enlightening volume. The reader learns that the Earth is surprisingly alive and altering constantly-sometimes through slow and equable changes and at times by violent and tremendous cataclysms, events from which gemstones issue.

Describes the appearance, formation, physical properties and characteristics, mining, and cutting of precious, semiprecious, and synthetic gemstones.

This fascinating work provides a truly stunning visual guide to the beautiful world of gemstones. It brings together a wealth of information in clearly worded text accompanied by a dazzling collection of color photographs showing gems in their natural and cut states. From subjects as diverse as identifying and collecting minerals and advanced testing, to ethical sourcing of gems, every aspect of gemstones is covered, and is presented with a wealth of research in easy-to-understand sections, making it a must-have reference work for anyone who wants to delve into the exciting world of gems.

The clearest and cleanest-cut photographic field guide to over 130 gemstones from around the world This compact visual guide is packed with more than 800 vivid full-colour photographs of more than 130 varieties of cut and uncut stones, organic gemstones, and precious metals. With authoritative text, clear photography, and a systematic approach, this concise guide to identification enables you to recognize each gemstone instantly. Each expertly written entry combines a precise description with annotated photographs to highlight the gemstone's chief characteristics and distinguishing features. Additional colour illustrations and photographs show uncut stones, colour variations, and a range of popular cuts, while bands on each entry provide at-a-glance facts for quick reference. Beginners to gem collecting will benefit from the detailed introduction that defines what a gemstone is, explains the physical and optical properties used to identify and classify gemstones, and shows how they have been fashioned and even imitated throughout history. To help with the initial stages of identification a colour key illustrates the variety of colours found within natural and synthetic gemstones, and a glossary explains the relevant scientific and technical terms.

A guide to the identification, structure, and uses of precious and semi-precious stones, novelty stones, agates, and crystals.