Aluminium silicate
…as minerals or synthetic. Their chemical formulae are often expressed as xAl2O3·ySiO2·zH2O. It is known as E number E559. Andalusite, kyanite, and sillimanite are the principal aluminium silicate minerals. The triple point of the three polymorphs is located at a temperature of 500 °C (932 °F) and a pressure…