Johanna Feary, Paul Cullinan, in Encyclopedia of Respiratory Medicine(Second Edition), 2022. Manganese Production and sources of exposure. Manganese ores, chiefly pyrolusite (MnO 2), are mined mainly in South Africa but there are smaller deposits in Australia, China, Brazil, India, Ukraine and some African and Asian states.Almost all manganese is used, for its anti …
pyrolusite, common manganese mineral, manganese dioxide (MnO2), that constitutes an important ore. Always formed under highly oxidizing conditions, it forms light-gray to black, metallic, moderately heavy coatings, crusts, or fibres that are alteration products of other manganese ores (e.g., rhodochrosite); bog, lake, or shallow marine products; or deposits left …
The key difference between pyrolusite and psilomelane is that pyrolusite has a tetragonal crystal system, whereas psilomelane has a monoclinic crystal system. Furthermore, pyrolusite has a metallic luster, while the luster of psilomelane is sub-metallic. They have different streak colors as well; e.g. streak color of pyrolusite is black to ...