Growth mechanism of Herring-Bone and Hour-glass synthetic gypsum

Abstract

Synthetic gypsum crystals are grown from sodium meta silicate gel when 1M calcium chloride solution diffuses into the gel imbedded with 1M amonium sulphate solution. Acicular-shaped crystals of Herring-Bone structure are observed. When methanol was added to the gel medium, tabular crystals revealing Hour-glass structure are rarely observed. In the presence of methanol the silicate particles are inhibited from being incorporated into the crystals as a result of pushing and incorporating mechanisms. Inclusion of silicate particles in traces gives rise to Hour-glass pattern. The implications are discussed.