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Related to anorthite: labradorite


A white to gray variety of plagioclase feldspar that contains a high proportion of calcium to sodium and occurs in alkaline igneous rocks such as gabbro and anorthosite.

[From Greek an-, not; see a-1 + orthos, straight (from its oblique crystals).]

an′or·thit′ic (-thĭt′ĭk) adj.
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.


(Minerals) a white to greyish-white or reddish-white mineral of the feldspar group and plagioclase series, found chiefly in igneous rocks and more rarely in metamorphic rocks. It is used in the manufacture of glass and ceramics. Composition: calcium aluminium silicate. Formula: CaAl2Si2O8. Crystal structure: triclinic
[C19: from an- + ortho- + -ite1]
anorthitic adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ænˈɔr θaɪt)

a white or gray feldspar mineral, CaAl2Si2O8, calcic plagioclase.
[1823; an-1 + Greek orth(ós) straight + -ite1]
an`or•thit′ic (-ˈθɪt ɪk) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.anorthite - rare plagioclastic feldspar occurring in many igneous rocksanorthite - rare plagioclastic feldspar occurring in many igneous rocks
oligoclase, plagioclase - any of a series of triclinic feldspars that form rocks
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
The presence of aluminous minerals like anorthite, scapolite or spinel is generally a reliable indicator of marble.
The ground WC mainly consists of crystalline phases including anorthite, quartz, portlandite, and CSH.
Ma, "Ca 2+ and OH--release of ceramsites containing anorthite and gehlenite prepared from waste lime mud," Journal of Environmental Sciences, vol.
The used standards for major, minor, and REE components were wollastonite (Si), anorthite (Al, Ca), omphacite (Na), olivine (Mg), K-feldspar (K), Zr-jarosite (Zr), ilmenite (Ti), Cr pure (Cr), rhodonite (Mn, Zn), fayalite (Fe), celestine (Sr), sanbornite (Ba), and F-apatite (F).
However, to the best of our knowledge, most studies on the effect of S[O.sub.2] have been performed in rocks containing Ca-rich minerals (e.g., calcite and anorthite), easily buffering the pH [4, 6, 8, 12-16].
The only particularity found is for the paste with presence of limestone (M3), in which formation of calcium feldspar (anorthite) was evidenced.
The study by FARIA (2008) demonstrated that the crystal grains are richer in Na at their periphery and richer in Ca at the core, so the composition of the borders is albite (the sodic plagioclase), and the core is anorthite (the calcic plagioclase).
[54] Luttge A, Bolton EW, Lasaga AC (1999) An interferometric study of the dissolution kinetics of anorthite: The role of reactive surface area.
Above 850[degrees]C, the decomposition of calcite can give rise to high-temperature calcosilicates and alumino-calcosilicates, member of the pyroxene group, such as the diopside, plagioclase feldspars (anorthite), gehlenite and wollastonite (Papachristodoulou et al.
From that point, material decomposition reduced the mass fraction of anorthite and substance transformation improved that of the microcline.