Glass Ceramic materials were developed around 1950's. Thereafter many developments and researches have been carried out over these materials and now these become technologically important and useful in research, engineering and commercial fields. Various properties of glass ceramics depend over microstructure, phase assemblage and bulk chemical composition. Glass formation, workability, tendency towards nucleation as well as crystallization is controlled by the bulk chemical composition. Properties like density, coefficient of thermal expansion and chemical durability are controlled by phase...