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

The moon is just sitting there waiting for us to colonize it—85 percent of the rocks in the lunar highlands are a mineral called anorthite, which is made of aluminum, silicon, calcium and oxygen.

From Scientific American

Of their minerals felspar Is usually the most abundant, and is principally labradorite and bytownite, though anorthite occurs in some, while oligoclase and orthoclase have been found in others.

From Project Gutenberg

Albite, the sodium felspar, has 68.8 per cent of silica, and the species between this and anorthite are regarded as mixtures of albite and anorthite molecules.

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

Gabbro, from Carlingford Hill, Ireland, consisting of anorthite, augite, a little olivine, and magnetite.

From Project Gutenberg