orthoclase

American  

[awr-thuh-kleys, -kleyz] / ˈɔr θəˌkleɪs, -ˌkleɪz /

noun

1. a common white or pink mineral of the feldspar group, KAlSi 3 O 8 , having two good cleavages at right angles, and found in silica-rich igneous rocks: used in the manufacture of porcelain.

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orthoclase British  

/ ˈɔːθəʊˌkleɪs, -ˌkleɪz /

noun

1. a white to pale yellow, red, or green mineral of the feldspar group, found in igneous, sedimentary, and metamorphic rocks. It is used in the manufacture of glass and ceramics. Composition: potassium aluminium silicate. Formula: KAlSi 3 O 8 . Crystal structure: monoclinic

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orthoclase Scientific  

/ ôr′thə-klās′ /

1. A white to yellowish red monoclinic mineral of the potassium feldspar group that forms from medium- to low-temperature magmas. Chemical formula: KAlSi ₃ O ₈ .

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Etymology

Origin of orthoclase

1840–50; ortho- + -clase < Greek klásis cleavage, breaking

Example Sentences

See Examples For:

orthoclase

Felsic is the compositional term applied to continental igneous minerals and rocks that contain an abundance of orthoclase feldspar.

From Textbooks ● Jan. 1, 2017

Felspar is a generic term which embraces a number of species, such as orthoclase or potash-felspar, albite or soda-felspar, and anorthite or lime-felspar.

From Geology by James Geikie

Last come orthoclase, quartz, microcline and micropegmatite, which fill up the irregular spaces left between the earlier minerals.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3 "Gordon, Lord George" to "Grasses" by Various

Those yielded by orthoclase must generally abound in potash, while albite and labradorite, containing little or none of that element, must produce soils in which it is deficient.

From Elements of Agricultural Chemistry by Thomas Anderson

The last of these minerals occurs in small irregular patches between the idiomorphic felspars which Dr J. J. H. Tean has found to be a soda orthoclase.

From The Project Gutenberg Encyclopedia Volume 1 of 28 by Project Gutenberg