Pyrolusite (MnO): Pyrolusite is the most prevalent manganese mineral and serves as the primary ore mineral for manganese. It appears black to dark gray and has a metallic luster. Psilomelane: Psilomelane is another manganese oxide mineral, containing water and varying amounts of impurities like oxides of barium (Ba), potassium (K), and sodium (Na). Its manganese content typically ranges from 45% to 60%. Manganite (MnO·HO): Manganite contains approximately 62.4% manganese. It plays a role in manganese ore deposits. Braunite (3MnO·MnSiO): Braunite has around 62% manganese and about 10% silicon dioxide (SiO).