Definition of pyrolusite in English:

pyrolusite

noun

  • [mass noun] A black or dark grey mineral with a metallic lustre, consisting of manganese dioxide.

    • ‘Scheele produced chlorine by treating the mineral pyrolusite with hydrochloric acid (HCl).’
    • ‘Acicular crystals and crystal aggregates of pyrolusite are found in vugs in the pegmatites of the district.’
    • ‘The ore, a mixture of ‘psilomelane’ and pyrolusite with much manganiferous limonite, contains masses of cerussite.’
    • ‘It never occurs as a free element, but only in ores such as pyrolusite, manganite, psilomelane, and rhodochrosite.’

Origin

Early 19th century: from pyro- ‘fire, heat’ + Greek lousis washing (because of the mineral's use in decolorizing glass).

Pronunciation:

pyrolusite

/ˌpʌɪrə(ʊ)ˈluːsʌɪt/