nepheline

A feldspathoid mineral of silica-poor igneous, plutonic and volcanic rocks. Chemically, Nepheline is a plagioclase feldspar with insufficient silica to satisfy the chemical bonds. Because of the unfilled bonds, Nepheline weathers rapidly and can only be seen as inclusions in freshly broken rock. ,Chemical composition: Sodium potassium aluminum subsilicate, (Na,K)Al,SiO ,Physical properties: Mohs Hardness: 5.5-6.0 Specific gravity: 2.5-2.6 Color: Colorless, white, gray, reddish, smoky; transparent to translucent Fracture: Subconchoidal Cleavage: Good prismatic Habit: Hexagonal-Hexagonal pyramidal Fluorescence: Often orange-red in portions of crystals

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  • Nepheline — General Category Silicate mineral Chemical formula (Na,K)AlSiO4 …   Wikipedia

  • Néphéline — Catégorie IX : silicates[1] Général …   Wikipédia en Français

  • néphéline — ● néphéline nom féminin Aluminosilicate de sodium du système hexagonal, appartenant au genre feldspathoïde. (La néphéline se forme dans les roches magmatiques sous saturées en silice [syénite néphélinique, phonolite].) ⇒NÉPHÉLINE, subst. fém.… …   Encyclopédie Universelle

  • Nepheline — Néphéline Néphéline Catégorie IX : silicates Général …   Wikipédia en Français

  • nepheline — [nef′əlīt΄nef′ə lēn΄, nef′əlin] n. [Fr néphéline < Gr nephelē, cloud (see NEBULA) + ine, INE1] a hard, light colored, hexagonal mineral, (Na,K)AlSiO4, used in making glass, china, etc.; sodium potassium aluminum silicate: sometimes called… …   English World dictionary

  • Nepheline — Neph e*line (n[e^]f [ e]*l[i^]n), Nephelite Neph e*lite (n[e^]f [ e]*l[imac]t), n. [Gr. nefe lh cloud: cf. F. n[ e]ph[ e]line. Cf. {Nebula}.] (Min.) A mineral occuring at Vesuvius, in glassy hexagonal crystals; also elsewhere, in grayish or… …   The Collaborative International Dictionary of English

  • nepheline — /nef euh lin/, n. a feldspathoid mineral, essentially sodium aluminum silicate, NaAlSiO4, occurring in alkali rich volcanic rocks. Also, nephelite /nef euh luyt /. [1805 15; < F néphéline, equiv. to néphél ( < Gk nephéle cloud) + ine INE2] * * *… …   Universalium

  • nepheline — also nephelite noun Etymology: French néphéline, from Greek nephelē cloud more at nebula Date: circa 1814 a hexagonal mineral that is a usually glassy crystalline silicate of sodium, potassium, and aluminum common in igneous rocks • nephelinic… …   New Collegiate Dictionary

  • nepheline — [ nɛf(ə)lɪn] noun a colourless, greenish, or brownish aluminosilicate mineral occurring in igneous rocks. Origin C19: from Fr. néphéline, from Gk nephelē cloud (because its fragments become cloudy on immersion in nitric acid) + ine2 …   English new terms dictionary

  • nepheline — nefelinas statusas T sritis chemija apibrėžtis Mineralas. formulė KNa₃[AlSiO₄]₄ atitikmenys: angl. nepheline rus. нефелин …   Chemijos terminų aiškinamasis žodynas

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