\En"sta*tite\, n. [Named fr. Gr. ? an adversary,
because infusible before the blowpipe.] (Min.)
A mineral of the pyroxene group, orthorhombic in
crystallization; often fibrous and massive; color grayish
white or greenish. It is a silicate of magnesia with some
iron. Bronzite is a ferriferous variety.