Among rock-forming minerals, the colorful tourmaline group is a favorite of both mineral collectors and gemologists. Superb examples are found at many locales worldwide, and in diverse geological settings from pegmatites to schists. Over 120 clear, crisp photos show each mineral in its geological context. This book will help mineral and gem collectors understand tourmaline mineralogy and see how changes in nomenclature reflect our evolving understanding of the group. The text explains the chemistry and taxonomy of the group, the environment in which tourmalines form, provides a detailed entry for each mineral including locality information and full-color photos wherever possible 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 provided for readers who wish to learn more. Every serious mineralogist, gemologist, and rock hound will need this book.

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.

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.

Among rock-forming minerals, the zeolite group is large and widespread, and is enormously important to industry. Zeolites form excellent crystals. The group is structurally complex and notable for its ability to exchange cations with surrounding solutions. Numerous diagrams help visualize important structural features that define various framework types. Over 200 photographs of these beautiful minerals show each species in its geological context. After a brief introduction, the general treatment of the subject begins with an explanation of the structural chemistry and taxonomy of the group. A section on their formation and geochemistry explains the kinds of environments where zeolites are formed. Then, an entry for each mineral series provides locality information and full-color photos wherever possible 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 provided for readers who wish to learn more about particular topics.

Over 140 color photos, diagrams, and text reveal the crystal structures, habits, names, and changing family relationships of silicate crystals. This thorough guide provides an introduction to crystallography, the current classification of silicate structures, and reviews orthosilicates, disilicates, chain silicates, sheet silicates, and framework silicates. Explore different ways the silicate tetrahedron can be arranged and great diversity of structures that result. Crystal structure is presented with drawings of ideal crystal forms and photographs of real crystals. In this way, mineral collectors can better understand the interplay between atomic arrangements and external habits, and ultimately develop an eye for recognizing crystal symmetry. This book is a must for all serious collectors of minerals.

Fluorite is found everywhere, has been important to industry for centuries, and is a minor ornamental material as well. Fluorite presents a fascinating array of colors, habits, and associated minerals and is widely available. See spectacularly large "museum quality" specimens that can be found. Fluorite presents a wealth of scientific opportunities to see crystallography, geochemistry, and solid-state physics at work in the natural world. This book includes information for the hobby collector or rock hound, as well as technical information for those who want to understand fluorite in greater depth. It provides over 140 full-color examples and extensive references to the formation and geographic locations of fluorite. This book is essential for everyone with a passion for minerals.

Since early 1989, a gem dealer I've known for years has been calling me every few weeks to brief me on mounting mayhem in Colombia's lucrative emerald market. The troubling gist of these calls is always this: There is a full-fledged turf war going on between that South American country's bustling drug and gem trades for control of its emerald ex port business. According to this dealer and several others, anywhere from two to four thousand emerald industry people, mostly miners and deal ers, have been murdered since 1980. No doubt the gem sector, itself never gun shy, has retaliated in full and in kind. After all, the two groups have banded together in an intermittent alliance against a common enemy-Communist guerillas-with results the CIA would envy. I mention this bloodshed because of something the gem dealer once said to me: "I bet you never think of what a gem has to go through to get to a jewelry store:' He's right. I tend to think of colored stones as things of beauty, not objects of gruesome power struggles between mining kingpins and drug lords. Can you blame me, or anyone with insider knowledge, if a gem sheds any connection with its past once sculpted by a cutter into the glittering mar vel we see in a jeweler's showcase? Like Odysseus listening to the sirens' song, we become victims of an aesthetics-induced amnesia.