Granite pegmatite crystals have long been admired by gem and mineral collectors as a source of fine specimens and gem materials. Pegmatites can host important deposits of ore minerals and industrial commodities, such as feldspar and mica. Their physical and chemical complexity presents daunting challenges to researchers who seek to better understand their nature and origins. With 209 stunning color photos and clear, authoritative text, this book provides a thorough discussion. Chapters cover pegmatite forms and distributions, interior structures, crystal, mineral, and gem pockets, and references for further study. Examples are from North America as well as worldwide.

Quartz is prized by both mineral collectors and lapidary artists. Over 130 vivid photographs of these beautiful minerals are presented to show each mineral in its geological context. Superb examples are found in diverse geological settings from pegmatites to Alpine clefts and hydrothermal veins. The silica minerals are chemically simple, yet structurally complicated. Several high temperature and high pressure polymorphs are known. In addition to the polymorphs of silica, this book treats related minerals, including: lechatelierite, opal, and two natural clathrates, chibaite and melanophlogite. After a brief introduction, the general treatment explains the chemistry and taxonomy of the group. A section on their formation and geochemistry describes the kinds of environments where these minerals are formed. Then, entries for each mineral provide locality information and full-color photos so that collectors can see what good specimens look like and which minerals one might expect to find in association with them. An extensive bibliography is also provided.

A comprehensive guide to the main varieties of birthstones, including their properties and structure. This volume features extracts from eight historical articles on the subjects of gemology and crystallography. This illustrative guide to birthstones is an ideal read for those who are interested in learning more about their spiritual connection to the natural world. Featured extracts taken from the following articles: - ‘Gems and Gem Materials’ Edward Henry Kraus - ‘The Natural History of Gems – Or, Decorative Stones’ C. W. King - ‘Diamonds and Precious Stones - Their History, Value and Distinguishing Characteristics’ Harry Emanuel - ‘A Manual of Precious Stones and Antique Gems’ Hodder M Westropp - ‘Precious Stones and Gems - Their History, Sources and Characteristics’ Edwin W. Streeter - ‘Gem Testing’ B W Anderso - ‘A Hand-Book of Precious Stones’ M. D. Rothschild - ‘Gem Stones and Their Distinctive Characters’ G. F. Herbert Smith

With the tremendous growth of population in this and neighboring states, there are more collectors than ever before and with the rapidly escalating prices for mineral and fossil specimens in the retail market, there is a great demand for displayable material. It has become necessary for professional geologists, hobby collectors, and commercial collectors to recognize each others existence and to try to work together within a framework of regulation, courtesy, and common sense so that material of scientific value is not lost and undue restrictions are not placed upon collecting. There is a continuing need for collectors and professionals to work together with resource managers and legislators to develop workable laws and rules affecting the collecting of minerals and fossils. This publication contains details information about collecting areas, divided by county to make for ease of use. Each collecting area contains information about the minerals, rocks, or fossils present, map recommendations, and other helpful tips on getting to the sites.

Describes hundreds of minerals and lists their geographic distribution, physical properties, chemical composition, and crystalline structure.