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talc
talc mineral ranging in color from white through various shades of gray and green to the red and brown of impure specimens, translucent to opaque, and having a greasy, soapy feel. It is a hydrous silicate of magnesium, Mg 3 Si 4 O 10 (OH) 2 , and usually contains small quantities of nickel, iron, and aluminum as impurities. It occurs commonly in folia (thin layers), but is also found in coarsely granular, finely granular, or cryptocrystalline masses. Soapstone , or steatite, is a massive, granular form of talc. French chalk is a fine-grained variety. Talc is usually associated with chlorite schists, serpentine, dolomite, and other metamorphic rocks; it is apparently a secondary mineral formed by the alteration of other magnesium silicates. There are important deposits of talc in Austria, Italy, France, and Canada and in the United States in California, North Carolina, Texas, Georgia, and Montana. Talc is used in making paper (as a filler), paints, face and talcum powder, soap, fireproof roofing, foundry facings, lubricants, linoleum and oilcloth, electrical insulation, and pottery. |
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"talc." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "talc." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1E1-talc.html "talc." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-talc.html |
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talc
talc A member of the 2:1 phyllosilicates (sheet silicates) with composition Mg6[Si4O10]2(OH)4; sp. gr. 2.58–2.83; hardness 1 (it has the lowest hardness on Mohs's scale of hardness); monoclinic; rare crystals are tabular, often massive; white to green; cleavage perfect hardness; massive talc (soapstone or steatite) can be formed during the low-grade metamorphism of siliceous dolomites; and as a secondary mineral during hydrothermal alteration of ultrabasic igneous rocks along shear planes. It is associated with serpentization with serpentine changing to talc and magnetite by addition of CO2. It is used extensively as a mineral filler.
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AILSA ALLABY and MICHAEL ALLABY. "talc." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "talc." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O13-talc.html AILSA ALLABY and MICHAEL ALLABY. "talc." A Dictionary of Earth Sciences. 1999. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-talc.html |
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talc
talc / talk/ • n. talcum powder. ∎ a white, gray, or pale green soft mineral with a greasy feel, occurring as translucent masses or laminae and consisting of magnesium hydroxyl silicate. • v. (talced, talc·ing) [tr.] powder or treat (something) with talc. DERIVATIVES: talc·ose / ˈtalkōs/ adj. ( Geol. ). talc·y / ˈtalkē/ adj. |
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"talc." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "talc." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O999-talc.html "talc." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-talc.html |
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talc
talc (hydrous magnesium silicate, Mg3Si4O10(OH)2). It occurs as rare tabulate crystals in a monoclinic system and as masses. It is used as base for talcum powder and in ceramics. Hardness 1; r.d. 2.6.
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"talc." World Encyclopedia. 2005. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "talc." World Encyclopedia. 2005. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O142-talc.html "talc." World Encyclopedia. 2005. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-talc.html |
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talc
talc species of translucent or shining minerals, e.g. mica. XVI. — F. talc or medL. talcum (whence talcum XVI) — Arab. ṭalḳ — Pers. talk.
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T. F. HOAD. "talc." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. T. F. HOAD. "talc." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O27-talc.html T. F. HOAD. "talc." The Concise Oxford Dictionary of English Etymology. 1996. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O27-talc.html |
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talc
talc (tal'k) n. a soft white powder consisting of magnesium silicate, used as a dusting powder.
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"talc." A Dictionary of Nursing. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "talc." A Dictionary of Nursing. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O62-talc.html "talc." A Dictionary of Nursing. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-talc.html |
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talc
talc
•calque, talc
•catafalque
•elk, whelk
•bilk, ilk, milk, silk
•Liebfraumilch • buttermilk • volk
•bulk, hulk, skulk, sulk
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"talc." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "talc." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O233-talc.html "talc." Oxford Dictionary of Rhymes. 2007. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-talc.html |
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