anorthite

[ an-awr-thahyt ]

noun

, Mineralogy.

1. a white or gray feldspar mineral, CaAl 2 Si 2 O 8 , calcic plagioclase.

anorthite

/ ænˈɔːθaɪt; ˌænɔːˈθɪtɪk /

noun

1. 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: CaAl 2 Si 2 O 8 . Crystal structure: triclinic

anorthite

/ ăn-ôr′thīt /

1. 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: CaAl 2 Si 2 O 8 .

Derived Forms

• anorthitic, adjective

Other Words From

• an·or·thit·ic [an-awr-, thit, -ik], adjective

Word History and Origins

Origin of anorthite¹

First recorded in 1825–35; an- ¹ + orth- + -ite ¹

Word History and Origins

Origin of anorthite¹

C19: from an- + ortho- + -ite ¹

Example Sentences

Rougemonite consists largely of anorthite with pyroxene as the only important ferro-magnesian constituent.

From Project Gutenberg

Anorthite is an essential constituent of many basic igneous rocks, such as gabbro and basalt, also of some meteoric stones.

From Project Gutenberg

The name anorthite was given to the Vesuvian mineral by G. Rose in 1823, on account of its anorthic crystallization.

From Project Gutenberg

Anorthite occurs in white translucent or transparent crystals.

From Project Gutenberg

Like labradorite and anorthite, it is a common constituent of basic igneous rocks, such as gabbro and basalt.

From Project Gutenberg