Search results for ""Author Robert J. Lauf""

Among rock-forming minerals, the vesuvianite group is best known through the many colorful crystals collected at the Jeffrey quarry, in Asbestos, Canada. Spectacular finds in China and Pakistan have added interest in this mineral group. The detailed text begins with an explanation of the chemistry and taxonomy of the group and a discussion of ongoing research into problems such as color, structure, and optically anomalous crystals. A section on their formation and geochemistry explains the kinds of environments where vesuvianites are formed. Each mineral has a detailed entry for information on important localities. Over 90 full-color photos show what good specimens look like and which minerals to expect to find associated with vesuvianites. Anyone with a passion for minerals will find this book fascinating.

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Over 115 striking color photos display pyroxene group minerals in all their forms and colors. This group of rock-forming minerals is best known to collectors through well-formed diopside crystals from many localities, including in Canada, the northeastern United States, the Alpine regions of Europe, and through the gem-quality spodumene found in pegmatites from California to Pakistan. Spectacular recent finds of diopside in Pakistan, hedenbergite at Dal'negorsk, Russia, and aegirine in Malawi have added to the interest in this mineral group. Several pyroxene species are important in the gem trade, including colored varieties of spodumene (kunzite and hiddenite), green "chrome" diopside, and jadeite, one of the two true jade minerals. The informative text provides an introduction to their formation and geochemistry and a detailed entry for each mineral, including color reference photos. This book is essential for every mineral collector.

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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.

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Garnet, with its many color varieties, is a favorite of both mineral collectors and gemologists. Superb examples are found at many locales worldwide, in both igneous and metamorphic rocks. Other members of the group are prized by species collectors and micromount enthusiasts. Over 120 color photos of these beautiful minerals show each species in its geological context. This book also explains how garnets are formed and the unique conditions that create fine crystals and vivid colors. After a brief introduction, the general treatment begins with an explanation of the chemistry and taxonomy of the group. A section on their formation and geochemistry explains the kinds of environments where garnets are formed. Detailed 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 provided.

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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.

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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.

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The axinite group of rock-formed minerals is well known to collectors through the spectacularly sharp crystals collected in quantity at Dal'negorsk and Puiva in Russia and at Tomas and other localities in Pakistan. Axinites are occasionally cut as gems. This concise monograph provides an up-to-date review of the group, incorporating recent changes to the names of three axinite species. The book is illustrated with over 90 full-color photographs of representative specimens. After a brief introduction, the text provides an explanation of the chemistry and taxonomy of the group and an illustration of the crystal structure and morphologies of real crystals. Detailed entries for each mineral provide information on notable localities and full-color photos wherever possible, so that readers can see what good specimens look like and which minerals one might expect to find in association with axinites. This book is a must for mineral collectors everywhere.

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Over 100 vivid color photographs of beautiful feldspar minerals show each species in its geological context. The feldspar minerals, as a group, make up nearly sixty percent of the earth’s crust. Large crystals are found at many locales worldwide, in both igneous and metamorphic rocks. Often, feldspar forms the matrix for stunning gem crystals found in pegmatites. This book explains how feldspars are formed and the complicated structural features that create fine crystals, twins, and vivid colors. After a brief introduction, the general treatment begins with an explanation of the chemistry and taxonomy of the group. A section on their formation and geochemistry explains the kinds of environments where feldspars are formed. Detailed 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 provided for further study.

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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.

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Over 90 striking color photos display minerals of the epidote group, well known to mineral collectors for their rich colors and the many interesting minerals with which they occur. Lapidary artists also value epidote, particularly in the form of unakite, and precious or semiprecious varieties of the related mineral zoisite, including thulite and tanzanite, some which have inclusions that allow them to be cut into popular catseyes. This informative book provides all presently known species, detailed entries for each of the eighteen minerals, and extensive locality information. This book will be of interest to those interested in developing a better understanding of silicate minerals.

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Mica is a broad term encompassing about forty minerals, ranging from the common to the rare, many at times forming excellent crystals jewelers use. This book feaures examples recently described among the 115 striking color photos and electron micrographs that illustrate the text. A detailed entry for each type includes information on where each is found, associations of micas with other minerals, pseudomorphs (minerals that masquerade as mica), and micas that fluoresce under UV light. This fascinating guide is for those interested in minerals.

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Collectors have long admired uranium and thorium minerals for their brilliant colors, intense ultraviolet fluorescence, and rich variety of habits and associates. Radioactive minerals are also critically important as our source of nuclear energy. Understanding them is crucial to the safe disposal of radioactive waste. This book provides a systematic overview of the mineralogy of uranium and thorium, generously illustrated with nearly 200 color photos and electron micrographs of representative specimens. Includes an historical discussion of the discovery of radioactive elements and the development of uranium and thorium ore deposits, a discussion of the geochemical conditions that produce significant deposits, and a description of important localities, their geological setting and history. Major occurrences of interest to mineral collectors are arranged geographically. The minerals are arranged systematically, to emphasize how they fit into chemical groups, and for each group a few minerals are selected to illustrate their formation and general characteristics. With the resurgence of interest in nuclear power, this book is an invaluable guide for mineral collectors as well as nuclear scientists and engineers interested in radioactive deposits.

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The mineral Titania is found in large, well-formed crystals at localities around the world. Over 100 color photos display three of the common titanium dioxide minerals: rutile, anatase, and brookite, along with a variety of interesting mineralogical phenomena. These are specimens the average collector will be able to obtain and study. The text is informative and thorough, listing the classic localities and describing both their fascinating diversity, including such phenomena as oriented growth, twinning, and pseudomorphism. The book also provides a solid explanation of the structures of rutile, anatase, and brookite and their phase relations. Their formation and geochemistry is described along with the environments in which the minerals were formed. For anyone fascinated by engaging minerals, this book will be a treasured source of useful information.

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Beryl in its many color varieties is a favorite of both mineral collectors and gemologists. Superb examples are found at many locales worldwide, mainly in pegmatites and schists. Other members of the group are prized by species collectors and micromount enthusiasts. This book explains how beryl is formed and the unique conditions that create fine aquamarines and emeralds. After a brief introduction, the general treatment begins with an explanation of the chemistry and taxonomy of the group. A section on their formation and geochemistry explains the kinds of environments where beryls are formed. Detailed 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 provided for further study. Over 100 photographs of these beautiful minerals show each species in its geological context.

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