Ankerite
1105537
213135252
2008-05-17T23:08:27Z
Riffle
1636478
internal link added
[[Image:Mineraly.sk - ankerit.jpg|thumb|200px|Ankerite]]
'''Ankerite''' is a [[calcium]], [[iron]], [[magnesium]], [[manganese]] [[Carbonate minerals|carbonate mineral]] of the group of rhombohedral carbonates with formula: [[calcium|Ca]]([[iron|Fe]], [[magnesium|Mg]], [[manganese|Mn]])([[carbon|C]][[oxygen|O]]<sub>3</sub>)<sub>2</sub>. In composition it is closely related to [[dolomite]], but differs from this in having magnesium replaced by varying amounts of iron(II) and manganese.
The crystallographic and physical characters resemble those of [[dolomite]] and [[siderite]]. The angle between the perfect rhombohedral cleavages is 73° 48', the [[Mohs hardness|hardness]] is 3.5 to 4, and the [[specific gravity]] is 2.9 to 3.1. The colour is white, grey or reddish to yellowish brown. The variety called normal ankerite is Ca<sub>2</sub>MgFe(CO<sub>3</sub>)<sub>4</sub>.
Ankerite occurs with siderite in deposits of iron-ore. It is one of the minerals of the dolomite-siderite series, to which the terms brown-spar, pearl-spar and bitter-spar have been historically loosely applied.
Ankerite can result from [[hydrothermal]] or direct [[groundwater]] [[Precipitation (chemistry)|precipitation]]. It can also be the result of [[metamorphic rock|metamorphic]] recrystallization of iron-rich [[sedimentary rocks]]. It is often found as a gangue mineral associated with [[gold]] and a variety of [[sulfide]] minerals in [[ore]] deposits.
It was first recognized as a distinct species by [[Wilhelm Karl Ritter von Haidinger|W. von Haidinger]] in 1825, and named by him after [[Matthias Joseph Anker]] (1771-1843) of Styria, an [[Austria]]n [[mineralogist]].
==See also==
*[[List of minerals]]
*[[List of minerals named after people]]
==References==
*[http://mineral.galleries.com/minerals/carbonat/ankerite/ankerite.htm Mineral Galleries]
*[http://www.mindat.org/min-239.html Mindat]
*[http://webmineral.com/data/Ankerite.shtml Webmineral]
{{1911}}
[[Category:Calcium minerals]]
[[Category:Magnesium minerals]]
[[Category:Iron minerals]]
[[Category:Manganese minerals]]
[[Category:Carbonate minerals]]
[[Category:Dolomite group]]
{{Manganese minerals}}
{{mineral-stub}}
[[ca:Ankerita]]
[[de:Ankerit]]
[[fr:Ankérite]]
[[it:Ankerite]]
[[lt:Ankeritas]]
[[hu:Ankerit]]
[[nl:Ankeriet]]
[[pl:Ankeryt]]
[[sk:Ankerit]]
[[sv:Ankerit]]
[[uk:Анкерит]]