Copper(II) arsenate
Copper arsenate (Cu3(AsO4)2.4H2O, or Cu5H2(AsO4)4.2H2O), also called copper orthoarsenate, tricopper arsenate, cupric arsenate, or tricopper orthoarsenate, is a blue or bluish-green powder insoluble in water and alcohol and soluble in aqueous ammonium and dilute acids. Its CAS number is