The Earth's crust contains about 1000 ppm of manganese. It is the 12th most abundant element in the Earth's crust. Soil contains 7–9000 ppm of manganese. Seawater only contains 10 ppm of manganese. The atmosphere contains 0.01 µg/m of manganese. Manganese mainly occurs as pyrolusite, braunite, psilomelane.