'Kutnohorite' is a rare calcium manganese magnesium iron
carbonate mineral with formula Ca(Mn,Mg,Fe)(CO
3)
2. It is a manganese rich analogue of the
dolomite-
ankerite series. It crystallizes in the
trigonal system and occurs as massive to bundled blades of white through rose pink to light brown crystal forms. The pink shades are due to increased manganese where as the brown colors are due to increased iron content. It shows the perfect three directions of cleavage typical of carbonates. It has a
Mohs hardness of 3.5 to 4 and a
specific gravity of 3.1 - 3.12. It is translucent to transparent with
refractive index values of nω = 1.727 and nε = 1.535.
It was first described in 1901 and named for its
type locality of Kutna Hora,
Bohemia,
Czech Republic.
References
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Mindat with location data
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Webmineral data