Element Manganese, Mn, Transition Metal
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Manganese History
Transitional metal Manganese was known from ancient Greece time. Pliny, an ancient naturalist and natural philosopher mentioned the black stone, which was used for the glass decolorizing by oxidizing ferrous iron to ferric iron in the molten glass. This black stone is manganese dioxide, MnO2 or Pyrolusite. In Georgia Pyrolusite was used for many centuries as an iron hardening material.
In 1774 Scheele, scientist from Sweden, was the first to recognize Manganese as a new element, rather than another iron modification. The same time his colleague J. Gahn from Sweden, produce metal Magnesium by heating Pyrolusite with carbon.
Manganese Occurrence
The average Manganese abundance in the Earth crust is 0.1%. In the magmatic rocks the Manganese abundance can vary between 0.06-0.2% by mass. Usually Manganese in lithosphere presents with +2 oxidizing state (Mn+2).
Same examples of Manganese ores:
Ilmenite-Mn is a titanium-iron ore with appreciable quantities of Manganese. 
Pyrolusite is a mineral consisting of MnO2 manganese dioxide, main ore for manganese production.
In water the average Manganese abundance is quite low, only about 10-6 - 10-5 g/l, the vast majority of Manganese is deposited into insoluble manganese-iron crystalline compounds.
Despite quite low abundance of Magnesium in living organisms, only about 10-3 - 10-5 per cents with slight increasing of concentrations in non-chordates organisms, Manganese plays crucial role organisms functionality. Manganese is a cofactor for many enzymes involved in such processes as photosynthesis, photosynthesis of nucleic acids, respiration and many others. Usually Manganese involved into coordination and activation of catalytic groups of proteins during catalytic act.
Daily human organism have to consume 3-8 mg of Manganese.
Manganese Neighbours
Colour Periodic Table | |