Crystallization of fluorcanasite-fluorrichterite glasses

The coefficient of thermal expansion of the obtained glass-ceramic materials ranged between 79 × 10−7 and 109 × 10−7 °C−1; and the density between 2.55 and 2.93 gm/cm3. The crystalline products attained Vickers' hardness values of 508-743 kg/mm2. The chemical durability of the materials was better in acidic than in alkaline solutions.