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Kyanite

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	Kyanite
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	Topics Kyanite Topic Home Kyanite, whose name derives from the Greek word kyanos, meaning blue, is a typically blue silicateSilicate In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by elec... mineralMineral Minerals are natural compounds formed through geological processes.... , commonly found in aluminiumAluminium Aluminium or aluminum is the chemical element in the periodic table that has the symbol Al and atomic number 13... -rich metamorphic pegmatitePegmatite Pegmatite is a very coarse-grained igneous rock that has a grain size of 20 mm or more; such rocks are referred to as pegm... s and/or sedimentary rockSedimentary rock Sedimentary rock is one of the three main rock groups and is formed in three main ways—by the deposition of the weath... . Kyanite is a diagnostic mineral of the Blueschist Facies of metamorphicMetamorphic Overview The term Metamorphic can be associated with a number of meanings:... rocks. Kyanite is a member of the aluminosilicate series, which includes the polymorphPolymorphism (materials science) Overview Polymorphism in materials science is the ability of a solid material to exist in more than one form or crystal structure.... andalusiteFacts About Andalusite Andalusite is an aluminium nesosilicate mineral with the chemical formula Al2SiO5.... and the polymorph sillimaniteSillimanite Summary Sillimanite also called Bucholzite is an alumino-silicate mineral with the chemical formula Al2SiO5.... . Kyanite is strongly anisotropicFacts About Anisotropy Anisotropy is the property of being directionally dependent.... , in that its hardnessMohs scale of mineral hardness Mohs' scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder mat... varies depending on its crystallographic direction. While this is a feature of almost all minerals, in kyanite this anisotropism can be considered an identifying characteristic. Uses of kyanite Kyanite is used primarily in refractory and ceramic products, including porcelain plumbing fixtures and dinnerware. It is also used in electrical insulators and abrasives. An interesting property of kyanite is that it undergoes an irreversible expansion when fired at high temperature. Kyanite has also been used as a gemstone, though this use is limited by its anisotropism and perfect cleavage. Kyanite is one of the index minerals that are used to estimate the temperature, depth, and pressure at which a rock undergoes metamorphism. Finally, as with most minerals, kyanite is a collector's mineral. Associated minerals Kyanite is usually found in association with its polymorphs, as well as other silicate minerals. These include: andalusiteAndalusite Andalusite is an aluminium nesosilicate mineral with the chemical formula Al2SiO5.... , Al₂SiO₅ sillimaniteSillimanite Sillimanite also called Bucholzite is an alumino-silicate mineral with the chemical formula Al2SiO5.... , Al₂SiO₅ quartzQuartz Quartz is one of the most common minerals in the Earth's continental crust.... , SiO₂ stauroliteStaurolite Staurolite is a red brown to black, mostly opaque, nesosilicate mineral with a white streak.... , Fe₂Al₉Si₄O₂₂(OH)₂ micaMica The mica group of sheet silicate minerals includes several closely related materials having highly perfect basal cleavage.... s, AB_2-3(X, Si)₄O₁₀(O,F,OH)₂ garnetGarnet The garnet group of minerals show crystals with a habit of rhombic dodecahedrons and trapezohedrons.... s, A₃B₂(SiO₄)₃ Alternative names Kyanite has several alternative names, including disthene, munkrudite and cyanite. White-grey kyanite is also called rhaeticite.