The physical and chemical properties of mullite
Chemical formula: 3Al2O3 · 2SiO2. colorless. It contains rose red or blue when it contains impurities. Orthorhombic, columnar or needle-like crystals. The melting temperature is about 1910 °C. It is produced when calcined clay, high alumina raw materials (such as kyanite, andalusite, sillimanite) and ceramics. It is the main component of clay bricks, high alumina bricks and porcelain. Produced in places like Moore Island in Scotland. It can also be obtained by electrofusion. See kyanite and andalusite.