andalusite

[ an-dl-oo-sahyt ]

noun

, Mineralogy.

1. an orthorhombic form of aluminum silicate, Al 2 SiO 5 , found in schistose rocks.

andalusite

/ ˌændəˈluːsaɪt /

noun

1. a grey, pink, or brown hard mineral consisting of aluminium silicate in orthorhombic crystalline form. It occurs in metamorphic rocks and is used as a refractory and as a gemstone. Formula: Al 2 SiO 5

andalusite

/ ăn′də-lo̅o̅′sīt′ /

1. A hard, grayish white to pinkish brown orthorhombic mineral. Andalusite occurs as nearly square prisms, often with cross-shaped cross sections, in metamorphic rocks. It is a polymorph of kyanite and sillimanite, but forms at shallower depths than they do, and at higher temperatures than kyanite and lower temperatures than sillimanite. Chemical formula: Al 2 SiO 5 .

Word History and Origins

Origin of andalusite¹

1830–40; named after Andalusia, where it was first found; -ite ¹

Example Sentences

In mica-gneisses sillimanite, kyanite, andalusite and garnet may occur.

From Project Gutenberg