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
anorthite in American English
(ænˈɔrˌθaɪt)
noun
a white or grayish variety of plagioclase, CaAl2Si2O8, found in basic igneous rocks
Derived forms
anorthitic (ˌanorˈthitic) (ænˈɔrˈθɪtɪk)
adjective
Word origin
< Gr an-, not + orthos, straight (see ortho-) + -ite1