orthorhombic

A plane of an orthorhombic crystal which is parallel both to the vertical axis and to the shorter lateral (brachydiagonal) axis.

A mineral consisting of titanic oxide, and hence identical with rutile and octahedrite in composition, but crystallizing in the orthorhombic system.

An iron-black mineral of metallic luster, occurring in small orthorhombic crystals, also massive

A mineral of the pyroxene group, orthorhombic in crystallization

An orthorhombic mineral of the pyroxene group, of a grayish or greenish black color, often with a peculiar bronzelike luster (schiller) on the cleavage surface.