sillimanite

[ sil-uh-muh-nahyt ]

noun

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

sillimanite

/ 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

sillimanite

/ 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 .

Word History and Origins

Origin of sillimanite¹

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

Word History and Origins

Origin of sillimanite¹

C19: named after Benjamin Silliman (1779–1864), US chemist

Example Sentences

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

From Project Gutenberg

Sillimanite usually forms exceedingly minute needles embedded in quartz.

From Project Gutenberg