sillimanite

American  

[sil-uh-muh-nahyt] / ˈsɪl ə məˌnaɪt /

noun

1. a mineral, aluminum silicate, Al 2 SiO 5 , occurring in the form of long, slender, and often fibrous crystals.

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sillimanite British  

/ ˈsɪlɪməˌnaɪt /

noun

1. a white, brown, or green fibrous mineral that consists of aluminium silicate in orthorhombic crystalline form and occurs in metamorphic rocks. Formula: Al 2 SiO 5

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sillimanite Scientific  

/ sĭl′ə-mə-nīt′ /

1. A usually white, pale-green or brown orthorhombic mineral occurring as long, slender, fibrous crystals in metamorphic rocks. It is a polymorph of andalusite and kyanite, but can form at higher temperatures than either of these. Chemical formula: Al ₂ SiO ₅ .

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Etymology

Origin of sillimanite

1825–30; named after B. Silliman; see -ite ¹

Example Sentences

See Examples For:

sillimanite

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

Rearrange the following minerals in order of increasing metamorphic grade: biotite, garnet, sillimanite, chlorite.

From Textbooks ● Jan. 1, 2015

The rocks of the sillimanite zone were likely heated to over 700°C, and therefore must have buried to depths between 20 km and 25 km.

From Textbooks ● Jan. 1, 2015

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

Each mineral may also enclose particles of the others; in the quartz, for example, small crystals of graphite, biotite, iron oxides, sillimanite or felspar may appear in great numbers.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 6 "Home, Daniel" to "Hortensius, Quintus" by Various