THE GROWING OF SINGLE CRYSTALS OF CALCITE UNDER HYDROTHERMAL CONDITIONS,

摘要

It was established (Dokl. Akad. Nauk SSSR 130(3). 610 2(1960) that under the conditions of expts. on the growing of calcite crystals at 400-450degrees and high pressures, H developed in the system CaCO,NaCl H2O-Fe. The at. H that formed reacted with CO2. Evolution of H,which also took place at 200degrees,and its reaction with CO2interfered with the growth of calcite crystals on nuclei: the crystals either did not grow at all,grew too slowly,or were imperfect. Evolution of H was eliminated by growing calcite crystals in a special glass vessel placed in an autoclave,so that contact of the soln. with the walls of the autoclave was prevented. By using this arrangement,calcite crystals with dimensions of the order of 1-2cm. were successfully grown in various chloride solns. at 150-200degrees in the dissolution zone temperature differentials of 10-25degrees,and pressures of 150-200kg./sq. cm.