Augite (Clinopyroxene)   Note the pigeonite twin lamellae in this grain. Pigeonite is a Ca-poor clinopyroxene. Besides clinopyroxene's 2nd order colors, another way to distinguish clinopyroxene from orthopyroxene is by clinopyroxene's inclined extinction.		UNC sample "norite" card
		Rock type clinopyroxenite
		Locality West Point, GA