English

Etymology

After the Austrian mineralogist Mathias Joseph Anker (1771-1843) in 1825.

Noun

1. Any of a group of mixed carbonate minerals, principally of calcium with iron, magnesium and manganese.

Quotations

• 1855 John William Dawson - Acadian geology

  In this second excavation the red ore is more largely mixed with the micaceous specular variety, and also includes large rounded blocks of ankerite and angular fragments of rock.

References

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 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 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 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 direct groundwater precipitation. It can also be the result of 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 W. von Haidinger in 1825, and named by him after Matthias Joseph Anker (1771-1843) of Styria, an Austrian mineralogist.

See also

• List of minerals
• List of minerals named after people

References

• Mineral Galleries
• Mindat
• Webmineral