orthoclase

or·tho·clase

O0128800 (ôr′thə-klās′, -klāz′)n. A white to yellowish red monoclinic mineral of the potassium feldspar group that forms from medium- to low-temperature magmas.

[Greek ortho-, ortho- + Greek klasis, a breaking (from klān, to break).]

orthoclase

(ˈɔːθəʊˌkleɪs; -ˌkleɪz) n (Minerals) 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: KAlSi3O8. Crystal structure: monoclinic

or•tho•clase

(ˈɔr θəˌkleɪs, -ˌkleɪz)

n. a common white or pink potassium feldspar mineral, KAlSi₃O₈, having two good cleavages at right angles, and found in silica-rich igneous rocks. [1840–50]

or·tho·clase

(ôr′thə-klās′) A type of feldspar consisting of potassium aluminum silicate. Orthoclase is typically white, pink, yellow, or brown, but it can also be colorless. It is especially common in igneous rocks.

Thesaurus

Noun

orthoclase - a white or colored monoclinic feldsparfeldspar, felspar - any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium

Translations

orthose

Orthoclase

enUK

orthoclase

[′ȯr·thə‚klās] (mineralogy) KAlSi₃O₈ A colorless, white, cream-yellow, flesh-reddish, or gray potassium feldspar that usually contains some sodium feldspar, either as albite or analbite or in some intermediate state; it is or appears to be monoclinic. Also known as common feldspar; orthose; pegmatolite.

Orthoclase

a rock-forming mineral of the feldspar group with the chemical composition K[AlSi₃O₈]. Orthoclase contains admixtures of Na (up to 8 percent Na₂O); less frequently, it contains Ba and small amounts of Fe, Ca, Rb, and Cs. It crystallizes in the monoclinic system to form prismatic crystals. Twin crystals are characteristic. Orthoclase, unlike microcline, exhibits perfect cleavage at a 90° angle (hence the name “orthoclase”). It is light pink, brownish yellow, or red. The mineral has a vitreous luster, a hardness on Mohs’ scale of 6–6.5, and a density of 2,550–2,580 kg/m³.

Orthoclase is one of the principal rock-forming minerals in magmatic rocks. Clusters of large orthoclase crystals occur in pegmatite veins. The mineral is often formed during regional and contact metamorphism. Orthoclase is used in the manufacture of glassware and ceramics.

orthoclase

or·tho·clase

orthoclase

or•tho•clase

or·tho·clase

Orthoclase

orthoclase

Orthoclase

orthoclase

Words related to orthoclase

noun a white or colored monoclinic feldspar

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