Amphibolite is a type of metamorphic rock primarily composed of amphibole minerals, particularly hornblende, and plagioclase feldspar. It typically forms under high-pressure and high-temperature conditions, often from the metamorphism of basalt or other mafic igneous rocks. The rock is usually dark in color, ranging from green to black, and has a coarse-grained texture. Amphibolite can be found in various geological settings, including mountain ranges and regions affected by tectonic activity. It is significant in understanding the processes of metamorphism and the conditions that lead to the formation of different rock types in the Earth's crust.