- a mineral, manganese metasilicate, MnSiO3, occurring usually in rose-red masses, sometimes used as an ornamental stone; manganese spar.
- a brownish translucent mineral consisting of manganese silicate in triclinic crystalline form with calcium, iron, or magnesium sometimes replacing the manganese. It occurs in metamorphic rocks, esp in New Jersey and Russia, and is used as an ornamental stone, glaze, and pigment. Formula: MnSiO 3
