peridotiitista

Peridotite is a dense, coarse-grained igneous rock. It is ultramafic, meaning it is composed primarily of the minerals olivine and pyroxene. The name peridotite is derived from peridot, the gemstone variety of olivine. This rock is typically dark green to black in color due to the high concentration of olivine. Peridotite is an important component of the Earth's upper mantle, where it exists under conditions of high pressure and temperature. It is one of the most abundant rock types in the mantle.

Geologists study peridotite found in xenoliths, which are fragments of mantle rock brought to the surface by volcanic eruptions, or in ophiolites, which are slices of oceanic crust and upper mantle that have been thrust onto continental crust. The composition and structure of peridotite can provide valuable insights into the processes occurring deep within the Earth. While rare at the surface, peridotite is a significant contributor to the planet's overall mass and geological activity. Its presence is crucial for understanding plate tectonics, mantle plumes, and the formation of magmas.