Augite is a common mineral found in many igneous rocks, particularly in basalt and gabbro. It belongs to the pyroxene group and is typically dark green to black in color. Augite has a prismatic crystal structure and can be identified by its two distinct cleavage angles, which are approximately 90 degrees. This mineral is rich in iron and magnesium, contributing to its density and hardness. Augite plays a significant role in understanding the formation and evolution of volcanic and plutonic rocks, making it important for geologists studying Earth's crust.