Kutnohorite is a rare calcium manganese carbonate mineral with magnesium and iron, that is a member of the dolomite group. It forms a series with dolomite, and with ankerite. The end member formula is CaMn²⁺(CO₃)₂, but magnesium Mg and iron Fe²⁺ commonly substitute for manganese Mn²⁺, with the Mn content varying from 38% to 84%, so the formula Ca(Mn²⁺,Mg,Fe²⁺)(CO₃)₂ better represents the species. It was named by Professor Bukowsky in 1901 after the type locality of Kutná Hora, Bohemia, in the Czech Republic. It was originally spelt "kutnahorite" but "kutnohorite" is the current IMA-approved spelling.