Non-metal oxides which form acids on contact with water.
The physical properties of the elements that make up a glaze can be quantified, for example, thermal expansion, density, mechanical strength, electrical conductivity and Opacity . These qualities can be predicted ( to some extent ) by the proportion of the elements in a glaze, using the Additive Law as proposed by Winkelman and Schott.
Aluminium Oxide (Al2O3).
Usually increases the viscosity of a glaze.
Common arw materils are Alimina Hydate, Calcined Aluminaand Clays.
An amphoteric oxide.
Oxides which can behave either as Basic Oxides or Acidic Oxides .