Subject: Quartz crystals in rocks

I'm looking for information on Quartz crystal as in rocks.

    Quartz is a common and abundant mineral occurring in a great variety of geological environments. It is present in many igneous and metamorphic rocks, is a major constituent of granite pegmatites, and a chief component of sandstones. It is the most common gangue mineral in hydrothermal metal-bearing veins and in many veins as essentially the only mineral present. Rock crystal quartz is found widely distributed, some of the more notable localities being: the Alps; Minas Gerais, Brazil; Madagascar; and Japan. The best quartz crystals from the United States are found at HotSprings, Arkansas, and Little Falls and Ellenville, New York. Smokey quartz is found in large and fine crystals in Switzerland; and in the United States at Pikes Peak, Colorado; Alexander County, North Carolina;and Oxford County, Maine. For more information, please consult a book on minerlogy, such as Dana's Manual of Mineralogy, which I believe is now in about its 20th edition.

Craig R. Glenn, Associate Professor
Department of Geology and Geophysics
University of Hawaii, Honolulu HI 96822

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