Pyrolusite

(Mineral)

Pyrolusite Is a member of the Rutile Group of very bright acicular (needle-shaped) crystals. It is a black or dark gray mineral with a metallic luster, consisting of manganese dioxide. It was named in 1827 from pyro- ‘fire, heat’ + Greek lousis ‘washing’ because of the mineral's use in decolorizing brown and green tints in glass making.  Pronunciation: piro-lo-sit