Sculptural works, vessels, or structural forms made from terracotta, a fairly coarse, porous clay product that when fired typically assumes a reddish or orange brown color, and often is left unglazed. When possible, for indexing use a more specific term, created locally by combining the material term plus a more specific object name, such as "terracotta" + "figurines."

Source: Art & Architecture Thesaurus 

http://vocab.getty.edu/page/aat/300047296