diaclasite

diaclasite Min.

(daɪˈækləsaɪt)

[f. Ger. diaklas (Breithaupt, 1823), f. Gr. διακλάειν to break through or asunder; on account of its easy cleavage.]

A bisilicate of iron and magnesium; a brassy yellow or greenish grey mineral of the pyroxene group, which is orthorhombic in crystallization.

Dana Min. 268.