Peridotite is a dense, coarse-grained igneous rock primarily composed of the minerals olivine and pyroxene. It is typically found in the Earth's mantle and is considered a major source of magnesium and iron. Due to its high melting point, peridotite plays a crucial role in the formation of magma and the dynamics of tectonic plates. This rock is often associated with ultramafic compositions, meaning it contains a low percentage of silica. Peridotite can also be transformed into other rock types, such as serpentinite, through a process called metamorphism. Its study helps geologists understand the Earth's interior and the processes that shape our planet.