Webster's Revised Unabridged Dictionary · 1913

Manganese

Manganese , noun

[French manganèse, Italian manganese, sasso magnesio; prob. corrupted from Latin magnes, because of its resemblance to the magnet. See Magnet, and compare Magnesia.]

(Chemistry) An element obtained by reduction of its oxide, as a hard, grayish white metal, fusible with difficulty (melting point 1244° 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].

An alloy of manganese with iron (called ferromanganese) is used to increase the density and hardness of steel.

Collocations (1)
Black oxide of manganese or Manganese dioxide or Manganese peroxide or Black manganese (Chemistry) , 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.