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Variscite is a hydrated aluminium phosphate mineral (·2H2O). It is a relatively rare phosphate mineral. It is sometimes confused with turquoise; however, variscite is usually greener in color. Variscite is a secondary mineral formed by direct deposition from phosphate-bearing water that has reacted with aluminium-rich rocks in a near-surface environment.〔Roncal-Herrero, T., Rodriguez-Blanco, J.D., Benning, L.G., Oelkers, E.H. (2009) Precipitation of Iron and Aluminum Phosphates Directly from Aqueous Solution as a Function of Temperature from 50 to 200°C. Crystal Growth & Design, 9, 5197-5205. doi: 10.1021/cg900654m.〕 It occurs as fine-grained masses in nodules, cavity fillings, and crusts. Variscite often contains white veins of the calcium aluminium phosphate mineral crandallite. Variscite is sometimes used as a semi-precious stone, and is popular for carvings and ornamental use. It was first described in 1837 and named for the locality of Variscia, the historical name of the Vogtland, in Germany. At one time, variscite was called ''Utahlite''. At times, materials which may be turquoise or may be variscite have been marketed as "variquoise". Appreciation of the color ranges typically found in variscite have made it a popular gem in recent years.〔Minerals of Nevada - Nevada Bureau of Mines Special Pub. 31 University of Nevada Press, 2004 Pages 78-81〕 Variscite from Nevada typically contains black spiderwebbing in the matrix and is often confused with green turquoise. Most of the Nevada variscite recovered in recent decades has come from mines located in Lander County.〔Gemstones of North America Volume III by John Sinkankas - Geoscience Press 1997〕 Notable localities are Lucin, Utah and Fairfield, Utah in the United States. It is also found in Germany, Australia, Poland, Spain〔http://www.patrimonigava.cat/lahistoriajaciment〕 and Brazil. Variscite Smithsonian.jpg|Cut slab of Variscite at the Smithsonian. Specimen is roughly 0.5 m wide. 00021 11 cm variscite.jpg|Variscite filling the cracks in siltstone. The sample is from Queensland, Australia. The width of the view is . Varis mcguin damali.jpg|Gem quality variscite, Nevada. ==See also== *List of minerals 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「variscite」の詳細全文を読む スポンサード リンク
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