n. - A dark-colored, basic, igneous rock, composed essentially of pyroxene and a triclinic feldspar with magnetic iron. By many authors it is considered equivalent to a coarse-grained basalt.
n. - A dark, crystalline, igneous rock, chiefly pyroxene with labradorite.
n. - Coarse-grained basalt.
n. - Diabase.
n. - Any dark, igneous rock composed chiefly of silicates of iron and magnesium with some feldspar.