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Ankerite Ca(Fe, Mg, Mn)(CO3)2
Benstonite (Ba, Sr)6(Ca, Mn)6Mg(CO3)13
Dolomite CaMg(CO3)2
Huntite CaMg3(CO3)4
Kutnohorite Ca(Mn, Mg, Fe)(CO3)2
Minrecordite CaZn(CO3)2
Norsethite BaMg(CO3)2

The borate minerals nordenskoldine and tusionite are isostructural with the
Dolomite Group minerals.

The Dolomite Group of Minerals

The Dolomite group and the Calcite group are both rhombohedral carbonates. All of the minerals in the dolomite group contain one of the following metal elements, manganese, magnesium, iron, or zinc, combined with a carbonate element and a calcium barium and/or strontium element . The dolomite group minerals incorporate two different elements with different radii in their crystal structure. This causes them to have a slightly more complicated structure than that of the Calcite group. The way that the minerals accommodate the varying radii of the different elements is by forming in three different layers. One of the layers being the usual carbonate element, another being the layer of calcium barium and/or strontium and one of the metal ions as the third layer. This triple layering causes the minerals to loose their twofold rotation and mirror plane, resulting in a bar 3 rhombohedral symmetry. The only common mineral in the dolomite group, is mineral dolomite. All of the others are quite rare. This is thought to be due to similar radius lengths in the elements of the other minerals in this group. Only dolomite has a notable difference in size between the calcium and the magnesium. All of the others have similar lengths making it hard for the ions to separate into layers.

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