- Ankerite
Ankerite is a
calcium ,iron ,magnesium ,manganese carbonate mineral of the group of rhombohedral carbonates with formula: Ca(Fe, Mg, Mn)(CO3)2. In composition it is closely related todolomite , 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 andsiderite . The angle between the perfect rhombohedral cleavages is 73° 48', the hardness is 3.5 to 4, and thespecific gravity is 2.9 to 3.1. The colour is white, grey or reddish to yellowish brown. The variety called normal ankerite is Ca2MgFe(CO3)4.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 directgroundwater precipitation. It can also be the result of metamorphic recrystallization of iron-richsedimentary rocks . It is often found as a gangue mineral associated withgold and a variety ofsulfide minerals inore deposits.It was first recognized as a distinct species by W. von Haidinger in 1825, and named by him after
Matthias Joseph Anker (1771-1843) of Styria, anAustria nmineralogist .ee also
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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]
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