十字石
Staurolite \Stau"ro*lite\, n. [Gr. ? a cross + -lite.] (Min.) A mineral of a brown to black color occurring in prismatic crystals, often twinned so as to form groups resembling a cross. It is a silicate of aluminia and iron, and is generally found imbedded in mica schist. Called also {granatite}, and {grenatite}.