basanite

basanite
/bas"euh nuyt', baz"-/, n. Petrog.
a basaltic rock composed chiefly of plagioclase, olivine, and augite.
[1745-55; < L basanites; see BASALT]

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▪ rock
      extrusive igneous rock that contains calcium-rich plagioclase feldspar (usually labradorite or bytownite), feldspathoid (usually nepheline or leucite), olivine, and pyroxene (titanaugite). Basanite grades into tephrite, which contains no olivine.

      In basanites and tephrites, the plagioclase occurs as large, single crystals (phenocrysts). The feldspathoid (nepheline) in nepheline-basanite and nepheline-tephrite occurs mainly in the matrix (groundmass), whereas that in leucite-basanite and leucite-tephrite (leucite) occurs abundantly in crystals as well. Olivine occurs as phenocrysts, as does the augite. Biotite, apatite, and titanium-rich magnetite are common accessories.

      Basanites and tephrites occur as gray to black rocks in sheets and flows. Places where basanites are found include Spain, Hungary, Italy, New Zealand, and the southwestern United States; tephrites are found in Germany, Italy, Portugal, Greenland, Uganda, and Colorado.

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  • Basanite — (pronEng|ˈbæsənaɪt) is an igneous, volcanic (extrusive) rock with aphanitic to porphyritic texture. The mineral assembly is usually abundant feldspathoids (nepheline or leucite), plagioclase, and augite, together with olivine and lesser iron… …   Wikipedia

  • Basanite — Bas a*nite, n. [L. basanites lapis, Gr. ba sanos the touchstone: cf. F. basanite.] (Min.) Lydian stone, or black jasper, a variety of siliceous or flinty slate, of a grayish or bluish black color. It is employed to test the purity of gold, the… …   The Collaborative International Dictionary of English

  • basanite — ● basanite nom féminin Basalte alcalin à fort déficit de silice, formé de plagioclase, d augite, d olivine et d un feldspathoïde …   Encyclopédie Universelle

  • Basanite — Basalte Structure géométrique typique des orgues basaltiques (Près du fleuve Skjálfandafljót, Islande) …   Wikipédia en Français

  • basanite — noun A basaltic extrusive rock, similar to chert Syn: lydite …   Wiktionary

  • basanite — bas·a·nite …   English syllables

  • basanite — ˈbasəˌnīt, azə noun ( s) Etymology: Latin basanites more at basalt 1. : touchstone 1 2. : an extrusive igneous rock composed of plagioclase, augite, olivine …   Useful english dictionary

  • Basanite — noun see touchstone I …   Useful english dictionary

  • Basaltes — Basalte Structure géométrique typique des orgues basaltiques (Près du fleuve Skjálfandafljót, Islande) …   Wikipédia en Français

  • Basaltique — Basalte Structure géométrique typique des orgues basaltiques (Près du fleuve Skjálfandafljót, Islande) …   Wikipédia en Français

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