水锰矿
Manganite \Man"ga*nite\, n. 1. (Min.) One of the oxides of manganese; -- called also {gray manganese ore}. It occurs in brilliant steel-gray or iron-black crystals, also massive. 2. (Chem.) A compound of manganese dioxide with a metallic oxide; so called as though derived from the hypothetical manganous acid.
manganite n : a black mineral consisting of basic manganese oxide; a source of manganese