Augite is an important rock-forming mineral in lots of igneous rocks, especially in gabbros and basalts, which is also present in a few hydrothermal metamorphic rocks. Augite is a part of an important solid solution series of the pyroxene group. The series includes the minerals hedenbergite, CaFeSi2 O6, and diopside, CaMgSi2 O6. A series occurs when ions (in this case iron and magnesium) can freely substitute between each other. Augite is the intermediate member of the series. However, augite is not just an intermediate, but is unique in that it contains percentages of sodium and aluminum that are mostly lacking in diopside and hedenbergite. The magnesium content is also larger in augite than in either of the other two minerals. The diopside-hedenbergite series is analogous to amphibole's tremolite- actinolite series.

Mineral specimens of augite, while ordinarily unattractive and not very interesting, can have some specimens that are very striking in appearance and are of interest to many mineral collectors. Its name is derived from the Greek word augites which mean "brightness" in allusion to its relatively high luster that is seen on some exceptional specimens.