In vitro growth of calcium carbonate crystals on bivalve shells: Application of two methods of synthesis

► Ammonium carbonate vapor diffusion method and coprecipitation method were used for CaCO3 crystals in vitro grown on fragments of molluscs shells. ► Effect of biomacromolecules released from shell substrates was clearly observed. ► Morphology of CaCO3 crystals vary with the method used. ► Polymorph and morphology of CaCO3 crystals were influenced by those of substrate, even if Mg+ ions were added in coprecipitation method.