Manganese
Manganese is sometimes found alloyed with iron naturally. These rocks, called meteorites, came from space. Pyrolusite is one of the main sources of manganese. It also occurs as manganese carbonate. Some silicates have manganese in them. The derivation of Manganese may have come from either the Latin 'magnes', meaning magnet, or from the black magnesium oxide, 'magnesia nigra'.