Quiz: Remember the definition of mal de mer?


[an-awr-thahyt] /ænˈɔr θaɪt/
noun, Mineralogy
a white or gray feldspar mineral, CaAl 2 Si 2 O 8 , calcic plagioclase.
1825-35; an-1 + orth- + -ite1
Related forms
[an-awr-thit-ik] /ˌæn ɔrˈθɪt ɪk/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for anorthite
  • The variety of plagioclase richest in sodium is known as albite, while the type wholly lacking in sodium is called anorthite.
British Dictionary definitions for anorthite


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
Derived Forms
anorthitic (ˌænɔːˈθɪtɪk) adjective
Word Origin
C19: from an- + ortho- + -ite1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
anorthite in Science
A white to gray triclinic mineral of the plagioclase feldspar group. Anorthite is the plagioclase mineral that is richest in calcium and occurs in alkaline igneous rocks such as gabbro. Chemical formula: CaAl2Si2O8.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for anorthite

Many English speakers likely know this word

Word Value for anorthite

Scrabble Words With Friends