ABSTRACT

As one of the steps that lead to an understanding of the secretion of magnesian calcite in skeletal parts of marine organisms, the laboratory synthesis of the mineral from aqueous solutions was carried out at low temperatures and pressures. The conditions of the laboratory synthesis of magnesian calcites are shown in this paper. Magnesian calcites are precipitated from calcium bicarbonate solutions containing magnesium ions and certain organic materials such as organic acids, which are found in the body fluids of carbonate-secreting organisms, in various concentrations.