manganese

n. 1 grey brittle metallic element. 2 black mineral oxide of this used in glass-making etc. [italian: related to *magnesia]

n. An element obtained by reduction of its oxide, as a hard, grayish white metal, fusible with difficulty, but easily oxidized. Its ores occur abundantly in nature as the minerals pyrolusite, manganite, etc. Symbol Mn. Atomic weight 54.8.