Pyrolusite

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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 used in discharging the brown and green tints of


     glass (whence its name).
     [1913 Webster]

From WordNet (r) 2.0 [wn]:

  pyrolusite
       n : a mineral consisting of manganese dioxide; an important
           source of manganese