Chromium carbonate

Chromium carbonate, typically chromium(III) carbonate with the formula Cr₂(CO₃)₃, is an inorganic compound appearing as a bluish-green amorphous powder. It has a molecular weight of approximately 284 g/mol and is insoluble in water, decomposing upon heating to chromium(III) oxide and carbon dioxide. The compound features chromium in the +3 oxidation state coordinated with carbonate ligands.​

Structurally, it exists as a basic or hydrated salt rather than a simple neutral carbonate due to stability issues, often represented as Cr₂(CO₃)₃ or related forms. It is prepared by reacting chromium salts with carbonates under controlled conditions and exhibits light blue to green hues in pure forms.​

Used in the preparation of chromic salts, pigments, and as a precursor in chromium chemistry, it requires careful handling due to chromium toxicity and irritant properties.