- Kutnohorite
Kutnohorite is a rare calcium manganese magnesium iron
carbonate mineral with formula Ca(Mn,Mg,Fe)(CO3)2. It is a manganese rich analogue of thedolomite -ankerite series. It crystallizes in thetrigonal 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 aMohs hardness of 3.5 to 4 and aspecific gravity of 3.1 - 3.12. It is translucent to transparent withrefractive 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
* [http://www.mindat.org/min-2299.html Mindat with location data]
* [http://www.webmineral.com/data/Kutnohorite.shtml Webmineral data]
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