Agate ware - Pottery made from clays of two differing colours, not completely mixed. The result is a srtreaked effect resembling agate.

Alumina - Aluminium oxide. It is used to bed bone china in the biscuit firing. A fine white powder with a high fusing temperature.

Antimony oxide - Produces a yellow colour in glazes.

Ash glaze - A glaze made with ground ash, usually wood ash and sometimes mixed with other materials.