Diopside is a monoclinic pyroxene mineral. It forms complete solid solution series with hedenbergite and augite, and partial solid solutions with orthopyroxene and pigeonite. It forms variably colored, but typically dull green crystals in the monoclinic prismatic class. Diopside is an important rock forming mineral in several metamorphic and basic to ultra basic igneous rocks, also found in meteorites.
Diopside is a very common mineral and forms as an accessory mineral in many environments, and is an important constituent of skarn rocks. Diopside forms a series with Hedenbergite, the iron equivalent of Diopside, and may be partially replaced by it.