pyrolusite Meaning, Definition & Usage

  1. noun a mineral consisting of manganese dioxide; an important source of manganese

WordNet

Pyr`o*lu"site noun
Etymology
Pyro- + Gr. to loose, or a loosing.
Definitions
  1. (Min.) Manganese dioxide, a mineral of an iron-black or dark steel-gray color and metallic luster, usually soft. Pyrolusite parts with its oxygen at a red heat, and is extensively used in discharging the brown and green tints of glass (whence its name).

Webster 1913