Terracotta:
Definition:

A hollow block, made from a low-grade fireclay or ganister, which is kiln fired at a high temperature to produce a fine even textured surface which may be red or buff. The blocks can be plain or moulded to provide architectural details; large designs are achieved by grouping the blocks and incorporating them in face brickwork. Traditional terracotta is normally unglazed but in more recent times coloured glazing has been used for Faience Work.