Manganite

[mæŋgәnait]

(noun.) a black mineral consisting of basic manganese oxide; a source of manganese.

Typed by Eugenia--From WordNet

(n.) One of the oxides of manganese; -- called also gray manganese ore. It occurs in brilliant steel-gray or iron-black crystals, also massive.

(n.) A compound of manganese dioxide with a metallic oxide; so called as though derived from the hypothetical manganous acid.

Editor: Philip