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

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

From Textbooks • Jan. 1, 2017

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

Granite containing orthoclase felspar produces a fairly fertile soil.

From Manures and the principles of manuring by Aikman, Charles Morton

Examples of substances exhibiting these three kinds of dispersion are borax, orthoclase and gypsum respectively.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

Felsite, or Felstone, a hard, compact igneous rock of somewhat flinty appearance, composed usually of quartz and orthoclase felspar intimately mixed, but sometimes of less highly siliceous minerals.

From The New Gresham Encyclopedia Volume 4, Part 3: Estremoz to Felspar by Various