/puy'reuh fil"uyt, puy rof"euh luyt'/, n.
Mineral. a phyllosilicate, AlSi2O5(OH), usually having a white or greenish color, and occurring in either foliated or compact masses, the latter variety being used like soapstone.
[1820-30; < G Pyrophyllit; so called because it exfoliates when heated. See PYRO-, -PHYLL, -ITE1]

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      very soft, pale-coloured silicate mineral, hydrated aluminum silicate, Al2(OH)2 Si4O10, that is the main constituent of some schistose rocks. The most extensive commercial deposits are in North Carolina, but pyrophyllite is also mined in California, China, India, Thailand, Japan, Korea, and South Africa. Talclike foliated masses occur in the Urals, in Switzerland, and in other localities.

      Pyrophyllite has long been used in slate pencils and tailor's chalk and was carved by the ancient Chinese into small images and ornaments. It has good insulating properties, and because it does not become fluid when fired, it is more useful than talc in refractory applications.

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Universalium. 2010.

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  • PYROPHYLLITE — Très semblable au talc, la pyrophyllite est un phyllosilicate d’alumine, de formule chimique: Al2(Si410)(OH)2, ou Al23, 4 Si2, H2O. Elle possède une certaine aptitude à se débiter en feuillets, d’où l’origine de son nom (de deux mots grecs: pyros …   Encyclopédie Universelle

  • Pyrophyllite — is a phyllosilicate mineral species belonging to the clay family and composed of aluminium silicate hydroxide: AlSi2O5OH. It occurs in two more or less distinct varieties, namely, as crystalline folia and as compact masses; distinct crystals are… …   Wikipedia

  • Pyrophyllite — Py*roph yl*lite, n. [Pyro + Gr. ? leaf.] (Min.) A mineral, usually of a white or greenish color and pearly luster, consisting chiefly of the hydrous silicate of alumina. [1913 Webster] …   The Collaborative International Dictionary of English

  • pyrophyllite — [pī΄rə fil′īt΄] n. [Ger pyrophyllit: see PYRO & PHYLL(O) & ITE1] a very soft, greasy, monoclinic mineral, AlSi2O5 (OH), that is similar to talc in structure, used as a lubricant and in making rubber, soap, etc.; hydrous aluminum silicate …   English World dictionary

  • pyrophyllite — noun a white or greenish aluminum silicate mineral (resembles talc) • Hypernyms: ↑mineral * * * ˌpīrōˈfiˌlīt, pīˈräfəˌl noun ( s) Etymology: German pyrophyllit, from pyr + phyll + it ite : a mineral AlSi2O5(OH) that is …   Useful english dictionary

  • Pyrophyllite — Ressemblant au talc, la pyrophyllite est un phyllosilicate d alumine. Sa formule chimique est la suivante : Al2(Si4O10)(OH)2, ou Al2O3, 4 SiO2, H2O. Elle possède une certaine aptitude à être en feuillets. L origine de son nom se décompose de …   Wikipédia en Français

  • pyrophyllite — pirofilitas statusas T sritis chemija apibrėžtis Mineralas. formulė Al₂[(OH)₂|Si₄O₁₀] atitikmenys: angl. pyrophyllite rus. пирофиллит …   Chemijos terminų aiškinamasis žodynas

  • pyrophyllite — noun Etymology: German Pyrophyllit, from Greek pyr + phyllon leaf more at blade Date: 1830 a soft usually white or greenish mineral that is a hydrous aluminum silicate, resembles talc, occurs in a foliated form or in compact masses, and is used… …   New Collegiate Dictionary

  • pyrophyllite — noun A soft, pale aluminosilicate mineral, somewhat resembling talc …   Wiktionary

  • pyrophyllite — (pi ro fil li t ) s. f. Silicate d alumine et de magnésie qui s exfolie sous l action du feu. ÉTYMOLOGIE    Pyro..., et, feuille …   Dictionnaire de la Langue Française d'Émile Littré

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