Greenstone is a type of metamorphic rock that is typically green in color, formed from the alteration of volcanic rocks under high pressure and temperature. It is primarily composed of minerals like chlorite, actinolite, and epidote, which give it its distinctive hue. Greenstone is often found in ancient geological formations and is significant in understanding the Earth's crust. This rock is commonly associated with greenstone belts, which are regions rich in gold and other minerals. These belts are important for mining and exploration, as they often contain valuable resources. Greenstone is also used in various decorative applications due to its attractive appearance.