HYDROTHERMAL GROWTH OF CALCITE SINGLE-CRYSTALS FROM H2O-CO2-CACO3 SYSTEM

Calcite single crystals were grown in H2O-CO2-CaCO3 system by a hydrothermal method. Low growth temperatures with large temperature differences were advantageous to obtain a large growth rate in this system. The maximum growth rate was 14.8 μm/day at 250°C and 53 MPa. The as-grown crystal on the cleavage plane was optically clear. Many growth hillocks and steps, initated through inhomogeneous growth, were also observed on as-grown surface. The H2O-CO2 system was an excellent solvent to obtain calcite single crystals at relatively low temperatures.