An important source of manganese

• A mineral consisting of manganese dioxide

Wikipedia Word definitions in Wikipedia
Pyrolusite is a mineral consisting essentially of manganese dioxide ( Mn O ) and is important as an ore of manganese. It is a black, amorphous appearing mineral, often with a granular, fibrous or columnar structure, sometimes forming reniform crusts. It ...

WordNet Word definitions in WordNet
n. a mineral consisting of manganese dioxide; an important source of manganese

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Pyrolusite \Pyr`o*lu"site\, n. [Pyro- + Gr. ? to loose, or ? a loosing.] (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 ...

Wiktionary Word definitions in Wiktionary
n. (context mineralogy English) A dark coloured mineral, consisting of manganese dioxide (manganeseoxygen 2 ), that is an important ore of manganese.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"manganese dioxide," 1828, the name given in Roman times, when it was used, in a heated state, to de-colorize glass, from Greek elements pyro- "by heat, by fire" (see pyro- ) + lysis "a loosening" (see lose ).