andalusite

American  

[an-dl-oo-sahyt] / ˌæn dlˈu saɪt /

noun

Mineralogy.

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

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andalusite British  

/ 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

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andalusite Scientific  

/ 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 .

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Etymology

Origin of andalusite

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

Example Sentences

In some cases, hornfels has visible crystals of minerals like biotite or andalusite.

From Textbooks • Jan. 1, 2015

Quartz is a good example as slightly different forms are stable between 0°C and 1800°C. The minerals kyanite, andalusite, and sillimanite are polymorphs with the composition Al2SiO5.

From Textbooks • Jan. 1, 2015

There is also a long list of accessory minerals which are present in gneisses with more or less frequency, but not invariably, as garnet, sillimanite, cordierite, graphite and graphitoid, epidote, calcite, orthite, tourmaline and andalusite.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 2 "Gloss" to "Gordon, Charles George" by Various

Younger felspars, as well as mica, are developed, and there arise also sillimanite, garnet, andalusite and many others.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various

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

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 2 "Gloss" to "Gordon, Charles George" by Various