Braunite is a
silicateA silicate is a compound containing an ion in which one or more central silicon atoms are surrounded by electronegative ligands. This definition is broad enough to include species such as hexafluorosilicate , [SiF6]2−, but the silicate species that are encountered most often...
mineral containing both di- and tri-valent
manganeseManganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
with the
chemical formulaA chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
:
Mn
2+Mn
3+6[O
8|SiO
4]. 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 a Mr.
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Braunite is a
silicateA silicate is a compound containing an ion in which one or more central silicon atoms are surrounded by electronegative ligands. This definition is broad enough to include species such as hexafluorosilicate , [SiF6]2−, but the silicate species that are encountered most often...
mineral containing both di- and tri-valent
manganeseManganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
with the
chemical formulaA chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
:
Mn
2+Mn
3+6[O
8|SiO
4]. 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 a Mr. Braun of
GothaGotha is a Kreis in the middle of Thuringia, Germany. Neighboring districts are Unstrut-Hainich, Sömmerda, the district-free city Erfurt, Ilm-Kreis, Schmalkalden-Meiningen and the Wartburgkreis.- History :...
,
ThuringiaThe Free State of Thuringia is located in central Germany. It has an area of and 2.29 million inhabitants, making it the sixth smallest by area and the fifth smallest by population of Germany's sixteen
Bundesländer...
,
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
.
A calcium iron bearing variant, named braunite II (formula: Ca(Mn
3+,Fe
3+)
14SiO
24), was discovered and described in 1967 from Kalahari, Cape Province,
South AfricaThe Republic of South Africa is a country located at the southern tip of Africa, with a coastline on the Atlantic and Indian Oceans. To the north lie Namibia, Botswana and Zimbabwe, to the east are Mozambique and Swaziland, while Lesotho is an independent country surrounded by South Africa.Modern...
.
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