Pyrolusite is a mineral composed primarily of manganese dioxide (MnO2). It is typically found in a black or dark gray color and has a metallic luster. Pyrolusite is the most important ore of manganese, which is essential for steel production and various chemical processes. This mineral often forms in sedimentary environments and can be associated with other manganese minerals. Pyrolusite is commonly used in the manufacturing of batteries, glass, and ceramics, as well as in water treatment processes to remove impurities. Its unique properties make it valuable in both industrial and environmental applications.