Augite or pyroxene is a black or greenish-black mineral, found, either as crystals, which are generally small, or as rounded grains and angular fragments, in basaltic and volcanic rocks.
"Geology"
James Geikie
They form a set of dikes of a fine-grained dark greenstone or dolerite, composed of feldspar and pyroxene, with occasional scales of mica and grains of pyrites.
"The Student's Elements of Geology"
Sir Charles Lyell
pyroxene group of minerals.
"The Student's Elements of Geology"
Sir Charles Lyell