or·tho·clase

(ôr′thə-klās′, -klāz′)

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).]

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

orthoclase

(ˈɔːθəʊˌkleɪs; -ˌkleɪz)

(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

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

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.

The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

ThesaurusAntonymsRelated WordsSynonymsLegend:

Noun

orthoclase - a white or colored monoclinic feldspar

feldspar, felspar - any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium

Translations

orthose

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References in periodicals archive

In the complex microprophries is very fine grained with orthoclase, perthite, quartz, biotite, magnetite, epidote as major minerals.

Evaluating the effect of grain size on mechanical parameters of rocks from different areas of Khyber Pakhtunkhwa, Pakistan

Non-stable fragments are represented by subangular K-feldspar grains (orthoclase and microcline) with [M.sub.d] 0.20 mm, polysynthetically twinned plagioclase, flakes of muscovite and biotite and subangular to subrounded clasts of lutite.

AN ADVANCED ASSESSMENT OF MECHANICAL FRACTURE PARAMETERS OF SANDSTONES DEPENDING ON THE INTERNAL ROCK TEXTURE FEATURES

The analysis showed that the composition of the original ash sample included mainly quartz, lime, anhydrite, calcite and smaller amounts of orthoclase, periclase, gehlenite, larnite, merwinite, pseudowollastonite, hematite, ettringite, melilite and dolomite (Table 2).

GRANULATION OF OIL SHALE ASH WITH SODIUM ALGINATE FOR THE REMOVAL OF PHENOLS FROM SHALE OIL WASTEWATER

Mineral Mohs Relative Scratch Test Vickers kg/ Hardness [mm.sup.2] Talc 1 Easily Scratched by 2.4 Fingernail Gypsum 2 Scratchable by Fingernail 36 Calcium 3 Easly Scratched by Knife 109 Carbonate Fluorite 4 Scratchable by Knife 189 Apatite 5 Difficult to Scratch 536 with Knife Orthoclase 6 Scratches with Steel File 795 Quartz 7 Scratches Window Glass 1,120 Topaz 8 Scratches Quartz 1,427 Corundum 9 Scratches Topaz 2,060 Diamond 10 Glass Cutter 10,060

Abrasion Characteristics Of Ground Calcium Carbonate Products

Ince, "Influence of orthoclase phenocrysts on point load strength of granitic rocks," Engineering Geology, vol.

Point Load Test of Half-Cylinder Core Using the Numerical Model and Laboratory Tests: Size Suggestion and Correlation with Cylinder Core

The diffraction reflections of orthoclase were found at 2[theta] values of 15.4, 21.0, 25.7, 27.5, and 30.1[degrees] (PDF 00-022-1212), whereas the diffraction reflections of muscovite were found at a 2[theta] value of 18.0[degrees] (PDF 00-0582036).

Adsorption Characteristics of Bixin on Acid- and Alkali-Treated Kaolinite in Aprotic Solvents

Qz: quartz; Ap: Apatite; Cpx: clinopyroxene; Pl: plagioclase; Or: orthoclase; Mag: magnetite; Ilm: ilmetite.

Chemical attributes of a remineralized Oxisol/Atributos quimicos de um Latossolo remineralizado

The low concentration of soluble [K.sub.2]O present in the phonolite may be due to the predominance of some constituent minerals such as: microcline (KAI[Si.sub.3][O.sub.8]), orthoclase (KAI[Si.sub.3][O.sub.8]), andesine [(Na,Ca)[(Si,Al).sub.4][O.sub.8]] and e nepheline [(Na, K) AlSi[O.sub.4]] (Teixeira et al., 2012), where K is retained by covalent bonds in the crystalline network of the mineral, presenting low K release to the soil solution (Martins et al., 2008).

Potassium solubilization in phonolite rock by diazotrophic bacteria

The XRD patterns indicate that the sanidine is mixed with other K.-feldspars, such as microclinc and orthoclase. The sand sample from the R8 ash layer (west area) also contained calcite.

Mineralogy of volcanically derived alluvial soils at Moshi, Tanzania