pyrolusite
/ˌpaɪrəʊˈljuːsaɪt/noun
mass noun
- a black or dark grey mineral with a metallic lustre, consisting of manganese dioxide软锰矿。
词源
early 19th cent.: from PYRO- 'fire, heat' + Greek lousis 'washing' （because of the mineral's use in decolourizing glass）.