is prepared by combining solutions of cobalt(II) sulfate and sodium bicarbonate:
:CoSO₄ + 2 NaHCO₃ -> CoCO₃ + Na₂SO₄ + H₂O + CO₂This reaction is used in the precipitation of cobalt from an extract of its roasted ores.

CoCO₃ adopts a structure like calcite, consisting of cobalt in an octahedral coordination geometry.