Augite is isomorphous with the minerals Diopside and Hedenbergite. It is an intermediarymember between these minerals, forming a series, but contains additional sodium and aluminum within its chemical structure. Strictly speaking, because of the variables in its chemical structure, Augite is really more of a group then a single mineral, but it is still classified a single mineral species by the IMA.
Augite is an important rock-forming mineral, and large crystals are fairly common. It is the most widespread member of the pyroxene group, and it frequently alters to many other minerals, including Hornblende, Chlorite, and Epidote. When altered to Actinolite, it is often called Uralite.
Augite usually occurs in dull crystals that are ugly and uninteresting. Occasionally, though, it is found in large lustrous crystals which are sought after by mineral collectors. The name Augite is derived from the Greek word augites, "brightness", in reference to the bright luster this mineral occasionally exhibits.
It has no practical uses. It is a rock forming mineral, in that, it does help other minerals to conbine into rocks.