Mineralogy and Crystallography

A Dictionary of Earth Sciences The Columbia Encyclopedia, 6th ed. Further reading

pyrolusite

A Dictionary of Earth Sciences | 1999 | | Copyright

pyrolusite Common manganese mineral, MnO₂; sp. gr. 4.5–5.0; hardness 5–6 for crystals, decreasing to 2 when massive; tetragonal; black to bluish-grey; black streak; metallic lustre; crystals rare, acicular and rod like, but it is usually massive, cryptocrystalline, and dendritic on joints and bedding planes; cleavage prismatic when present; a secondary mineral found in the oxidized zone of manganese deposits, in quartz veins, and as nodules on the sea bed. Synthetic MnO₂ is used for dry batteries, as a decolourizer for glass, and in the manufacture of chemicals.

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pyrolusite

The Columbia Encyclopedia, 6th ed. | 2011 | Copyright

pyrolusite , naturally occurring manganese dioxide, MnO ₂ , a black mineral that crystallizes in the tetragonal system but is usually found in earthy or massive deposits. It is the principal source of manganese and its compounds, and it is extensively used in steel smelting and in the manufacture of dry-cell batteries. The main producing countries are Russia, Brazil, South Africa, Gabon, India, China, and Australia.

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"pyrolusite." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>.

"pyrolusite." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1E1-pyrolusi.html

"pyrolusite." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-pyrolusi.html

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