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]]