'Manganese dioxide' definitions:

Definition of 'Manganese dioxide'

From: GCIDE
  • Manganese \Man`ga*nese"\, n. [F. mangan[`e]se, It. manganese, sasso magnesio; prob. corrupted from L. magnes, because of its resemblance to the magnet. See Magnet, and cf. Magnesia.] (Chem.) An element obtained by reduction of its oxide, as a hard, grayish white metal, fusible with difficulty (melting point 1244[deg] C), but easily oxidized. Its ores occur abundantly in nature as the minerals pyrolusite, manganite, etc. Symbol Mn. Atomic number 25; Atomic weight 54.938 [C=12.011]. [1913 Webster +PJC]
  • Note: An alloy of manganese with iron (called ferromanganese) is used to increase the density and hardness of steel. [1913 Webster]
  • Black oxide of manganese, Manganese dioxide or {Manganese peroxide}, or Black manganese (Chem.), a heavy black powder MnO2, occurring native as the mineral pyrolusite, and valuable as a strong oxidizer; -- called also familiarly manganese. It colors glass violet, and is used as a decolorizer to remove the green tint of impure glass. [1913 Webster]