Bridgmanite << brihj `mah` nyt >> is a mineral found deep within Earth. Geologists believe it is the most abundant mineral on Earth. Bridgmanite is found in Earth’s mantle above a depth of about 1,700 miles (2,700 kilometers). The mantle is the layer of Earth below the surface crust and above the liquid core. It is solid and composed of rock rich in iron and magnesium. Geologists believe that more than 90 percent of the part of the mantle where bridgmanite is found is composed of the mineral.
Bridgmanite is made up of silicon, oxygen, magnesium, and iron. Its chemical formula is (MgFe)SiO3. The parentheses indicate that the amount of magnesium and iron in the mineral is variable. Bridgmanite is a silicate mineral because it contains silicon, oxygen, and one or more metallic elements. Silicates make up about 95 percent of Earth’s crust. Geologists classify minerals based on the structure—that is, the way the atoms are arranged in the crystal lattice. Bridgmanite belongs to the perovskite group of minerals.
Geologists determined that bridgmanite is abundant deep below the Earth’s surface from several lines of evidence. Bridgmanite is found in meteorites which are thought to represent the building blocks of planets in the solar system. Scientists have also created bridgmanite in the laboratory by subjecting rocks of similar composition to high heat and pressure. Such temperature and pressures exist in Earth’s mantle. In addition, there are places on Earth where mantle rocks are exposed at the surface. These rocks contain bridgmanite.
Bridgmanite is named for the American scientist Percy Williams Bridgman. Bridgman studied the behavior of matter at extremely high pressures, such as those that characterize Earth’s mantle where bridgmanite is found.
