dolomiittia

Dolomiittia is a proposed carbonate mineral in the dolomite group, characterized by a magnesium-calcium carbonate solid solution with distinct trace-element signatures. It is described primarily from metamorphosed carbonate rocks in the fictional Dolomian Basin. The mineral is named for its close association with dolomite-hosted rocks.

It was first described in a hypothetical 2012 paper by researchers K. Valenz and R. Cho and is named to reflect its occurrence in the Dolomian region.

Chemically, Dolomiittia corresponds to CaMg(CO3)2 with substitutions of Fe2+, Mn2+, and Sr2+ up to modest levels. Crystals are generally rhombohedral, closely resembling dolomite, with a vitreous to pearly luster. Hardness ranges from 3.5 to 4 on the Mohs scale; specific gravity is about 2.95 to 3.10.

Dolomiittia is reported from veins and pods within metamorphosed carbonate sequences, where magnesium-rich fluids have metasomatically altered calcite-rich rocks. Formation is thought to occur under regional metamorphism at moderate temperatures, typically 350–500°C, and is often associated with calcite, dolomite, siderite, and minor ankerite.

Its status within mineral databases is unsettled; some authors view Dolomiittia as a high-impurity variant of dolomite, while others designate it as a distinct mineral based on distinctive infrared spectra and trace-element chemistry. More research is needed for formal recognition.

See also Dolomite; Dolostone; Carbonate minerals; Mineral nomenclature.