[ sil-uh-muh-nahyt ]
/ ˈsɪl ə məˌnaɪt /


a mineral, aluminum silicate, Al2SiO5, occurring in the form of long, slender, and often fibrous crystals.

Words nearby sillimanite

Origin of sillimanite

1825–30; named after B. Silliman; see -ite1
Also called fibrolite. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for sillimanite

British Dictionary definitions for sillimanite

/ (ˈsɪlɪməˌnaɪt) /


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

Word Origin for sillimanite

C19: named after Benjamin Silliman (1779–1864), US chemist
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for sillimanite

[ sĭlə-mə-nīt′ ]

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: Al2SiO5.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.