Small amounts of gold and platinum were added to a glass composition of a particular mica based glass to investigate the influence of these additions on the mica crystallization. In the starting glass cabbage-shaped mica crystal aggregates are formed. The crystallization of phlogopite is catalyzed by gold. In the gold containing glass crystallize flat phlogopite crystals of a small size. In contrast to the added gold platinum do not markedly affect the phlogopite crystallization. Glass-ceramics containing platinum show the typical spherical mica crystal aggregated. Gold containing glass-ceramics posses an enhanced bending strength in comparison with both the starting glass-ceramic without additions of noble metals and the glass-ceramic containing platinum.
