pyrolusite

noun

1. a mineral consisting of manganese dioxide; an important source of manganese
   Terjemahkan ke Indonesia sumber: wordnet30
2. 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).
   Terjemahkan ke Indonesia sumber: webster1913