Pigeonite is a mineral with a variable chemical composition that belongs to the pyroxene group. This mineral often occurs in basalts, gabbros, and peridotites, and it is commonly found in the Earth's crust and on other planets. Some synonyms for pigeonite include augite, enstatite, diopside, hypersthene, and ferrohedenbergite. Augite is a mineral that has similar properties to pigeonite and is commonly found in igneous rocks. Enstatite is a pyroxene mineral that is similar to pigeonite but has a higher magnesium content. Diopside is also a pyroxene mineral but has a distinct green color and is commonly found in metamorphic rocks. Hypersthene is a mineral that has a similar chemical composition to pigeonite, while ferrohedenbergite is a mineral with a similar crystal structure to pigeonite.