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Pottery, porcelain, brick, and tile are all very similar in composition and method of manufacture, and with glass they provide the class of materials known as ceramics. These products are made from varying mixtures of clay, silica, and feldspar. The very first of them are usually prepared from natural clays which already contain silica and feldspar. These natural clays are made into a workable mud with water and then fired in special ovens. As the temperature rises, water is first driven from the mixture, then various decomposition products are formed and above 1250˚ C the feldspar fuses and binds the other materials present.

Porcelain is made of very fine white clay known as kaolin. Then very pure sands and feldspar are added.

Glass

Silicate materials include glass, porcelain, enamels and cement. Ordinary glass is a mixture of silicates in the form of super cooled liquid. It is made by melting a mixture of sodium carbonate, limestone and sand. Ordinary glass contains about 10% of sodium, 5% of calcium, and 1% of aluminium; the remainder is silicon and oxygen. It consists of an aluminosilicate tetrahedral framework, within which are embedded sodium ions and calcium ions.

Cement

Portland cement is an aluminosilicate powder which sets to a solid mass on treatment with water. Portland cement before treatment with water consists of a mixture of calcium silicates and calcium aluminate. When treated with water the calcium aluminate hydrolyzes and form calcium hydroxide and aluminium hydroxide. These substances react further with the calcium silicates and produce calcium aluminosilicates in the form of crystals.