Английская Википедия:Braunite
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Шаблон:Short description Шаблон:Infobox mineral
Braunite is a silicate mineral containing both di- and tri-valent manganese with the chemical formula: Mn2+Mn3+6[O8|SiO4].[1] Common impurities include iron, calcium, boron, barium, titanium, aluminium, and magnesium.
Braunite forms grey/black tetragonal crystals and has a Mohs hardness of 6 – 6.5.
It was named after the Wilhelm von Braun (1790–1872) of Gotha, Thuringia, Germany.[1]
A calcium iron bearing variant, named braunite II (formula: Ca(Mn3+,Fe3+)14SiO24), was discovered and described in 1967 from Kalahari, Cape Province, South Africa.[2][3]
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