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pyroxene
pyroxene An important group of inosilicates (chain silicates) comprising the orthorhombic pyroxenes (orthopyroxenes) and the monoclinic pyroxenes (clinopyroxenes) with the general formula XYZ2O6, where × = Mg, Fe, Ca, or Na; Y = Mg, Fe, Fe3+, or Al; and Z = Si (and some Al substitution). The main orthopyroxenes are enstatite and orthoferrosilite; the main clinopyroxenes include diopside, hedenbergite, augite, pigeonite, and jadeite, and also the alkali pyroxenes aegirine and aegirine augite (note that wollastonite, although similar to the pyroxenes, has a different atomic structure); sp. gr. 3.0–3.5; hardness 5–6; colours variable, but usually dark greens, browns, or black; vitreous lustre; crystals usually short or columnar prisms; well-marked cleavage; widely distributed in both igneous and metamorphic rocks.
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AILSA ALLABY and MICHAEL ALLABY. "pyroxene." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "pyroxene." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O13-pyroxene.html AILSA ALLABY and MICHAEL ALLABY. "pyroxene." A Dictionary of Earth Sciences. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-pyroxene.html |
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pyroxene
pyroxene , name given to members of a group of widely distributed rock minerals called metasilicates in which magnesium, iron, and calcium, often with aluminum, sodium, lithium, manganese, or zinc occur as X in the chemical formula XSiO 3 . The pyroxene minerals crystallize in three different systems—orthorhombic, monoclinic, and triclinic—but all have a fundamental prism with angles of 87° to 93° and cleavages parallel to the prism angles. They are commonly white, grayish white, greenish white, greenish black, black, or brown, but other varieties occur. Pyroxene minerals are found chiefly in igneous and metamorphic rocks and in lunar rocks. Varieties include enstatite, bronzite, hypersthene, diopside, wollastonite, augite, pectolite, spodumene, and rhodonite. |
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"pyroxene." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "pyroxene." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1E1-pyroxene.html "pyroxene." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-pyroxene.html |
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pyroxene
py·rox·ene / pīˈräkˌsēn; pə-/ • n. any of a large class of rock-forming silicate minerals, generally containing calcium, magnesium, and iron and typically occurring as prismatic crystals. |
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"pyroxene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "pyroxene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O999-pyroxene.html "pyroxene." The Oxford Pocket Dictionary of Current English. 2009. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-pyroxene.html |
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pyroxene
pyroxene Group of rock-forming, silicate minerals, usually coloured dark green, brown, and black. Crystals are usually short prisms with good cleavages. Hardness 2.3–4; r.d. 5.5–6.
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"pyroxene." World Encyclopedia. 2005. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "pyroxene." World Encyclopedia. 2005. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O142-pyroxene.html "pyroxene." World Encyclopedia. 2005. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-pyroxene.html |
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pyroxene
pyroxene •gamine • bromine • thiamine
•dopamine • amphetamine • histamine
•quinine • strychnine • mezzanine
•spalpeen • Philippine • lycopene
•gangrene • terrene • silkscreen
•windscreen • citrine • Dexedrine
•putting green • Benzedrine
•Irene, polystyrene
•widescreen • sight screen
•chlorine, chorine, Doreen, Maureen, Noreen, taurine
•smokescreen • rood screen
•sunscreen • fluorine • helleborine
•Gadarene • Hippocrene
•glycerine (US glycerin), nitroglycerine (US nitroglycerin)
•nectarine • wintergreen • Methedrine
•evergreen • wolverine • vaccine
•glassine • Essene • Rexine • piscine
•epicene • glycine • pyroxene
•Palaeocene (US Paleocene)
•Pliocene • Miocene • Holocene
•damascene • kerosene • Plasticine
•Pleistocene
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"pyroxene." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "pyroxene." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O233-pyroxene.html "pyroxene." Oxford Dictionary of Rhymes. 2007. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-pyroxene.html |
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