Nickel(II) carbonate

Nickel(II) carbonate is the chemical compound with the formula NiCO3. It is a pale green polymeric solid consisting of Ni2+ cations and [CO3]2- anions. NiCO3 does not actually dissolve in any solvent, but is readily decomposed by aqueous acids to give solutions containing the ion [Ni(H2O)6]2+, liberating water and carbon dioxide in the process. Pyrolysis of NiCO3 gives NiO:
 * NiCO3 → NiO  +  CO2