a white, brown, or green fibrous mineral that consists of aluminium silicate in orthorhombic crystalline form and occurs in metamorphic rocks. Formula: Al2SiO5
Word origin
C19: named after Benjamin Silliman (1779–1864), US chemist
sillimanite in American English
(ˈsɪləməˌnaɪt)
US
noun
a very hard, mineral, aluminum silicate, Al2SiO5, usually found in metamorphic rock as long, slender crystals of various colors
Word origin
after B. Silliman (1779-1864), U.S. chemist and geologist + -ite1