Noun
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).
Source: Webster's dictionaryThe brown, pink and red colors are from hematite (iron oxide; Femain Omain ); the yellows from limonite (FeO(OH)·nHmain O) ; and the purples are from pyrolusite ( Mn Omain ). Source: Internet
Scheele and others were aware that pyrolusite (now known to be manganese dioxide ) contained a new element, but they were unable to isolate it. Source: Internet
When he treated the pyrolusite with hydrochloric acid over a warm sand bath, a yellow-green gas with a strong odor was produced. Source: Internet