from
The Collaborative International Dictionary of English v.0.48
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]