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

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

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

From Textbooks • Jan. 1, 2015

It has the same percentage chemical composition as andalusite and sillimanite, but differs from these in its crystallographic and physical characters.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8 "Cube" to "Daguerre, Louis" by Various

The top of Kearsarge is composed of andalusite schist.

From The Bay State Monthly, Volume 3, No. 5 by Various

Where the schists of sedimentary origin have been pierced by these igneous intrusions, they are charged with contact minerals such as sillimanite, cordierite, kyanite and andalusite.

From The Project Gutenberg Encyclopedia Volume 1 of 28 by Project Gutenberg