feldspar

[ feld-spahr, fel- ]

noun
  1. any of a group of minerals, principally aluminosilicates of potassium, sodium, and calcium, characterized by two cleavages at nearly right angles: one of the most important constituents of igneous rocks.

Origin of feldspar

1
1750–60; feld- (<German: field) + spar3; replacing feldspath<German (Feld field + Spath spar)

Words Nearby feldspar

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British Dictionary definitions for feldspar

feldspar

felspar

/ (ˈfɛldˌspɑː, ˈfɛlˌspɑː) /


noun
  1. any of a group of hard rock-forming minerals consisting of aluminium silicates of potassium, sodium, calcium, or barium: the principal constituents of igneous rocks. The group includes orthoclase, microcline, and the plagioclase minerals

Origin of feldspar

1
C18: from German feldspat (h), from feld field + spat (h) spar ³

Derived forms of feldspar

  • feldspathic (fɛldˈspæθɪk, fɛlˈspæθ-), felspathic, feldspathose or felspathose, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for feldspar

feldspar

[ fĕldspär′, fĕl- ]


  1. Any of a group of abundant monoclinic or triclinic minerals having the general formula MAl(Al,Si)3O8, where M is either potassium (K), sodium (Na), or calcium (Ca) or less commonly barium (Ba), rubidium (Rb), strontium (Sr), or iron (Fe). Feldspars range from white, pink, or brown to grayish blue in color. They occur in igneous, sedimentary, and metamorphic rocks and make up more than 60 percent of the Earth's crust. When they decompose, feldspars form clay or the mineral kaolinite.

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