A coprecipitation of copper(II) and zinc(II) from complex sulfate solutions with natural calcite was investigated. The main features of the process and mineral forms of incorporation of heavy metals in a solid phase were determined. Sequential precipitation proceeds at pH 5.3–5.5 and 6.5–7.0 for copper(II) and zinc(II), respectively, in mode of pH autoregulation. Sediments were represented by copper and zinc hydroxosulfates: posnjakite and namuvite, respectively. Smithsonite and hydrozincite formation was not detected unlike precipitation of zinc(II) from monometallic sulfate solutions. The mechanism explaining the lack of zinc carbonates and the formation of mixed cation salts was suggested. The formation of hydroxosulfates should be considered in the thermodynamic description of the interaction of heavy metals with natural calcium carbonate.