stucco (stŭkˈō) [key], in architecture, a term loosely applied to various kinds of plasterwork, both exterior and interior. It now commonly refers to a plaster or cement used for the external coating of buildings, most frequently employed in Mediterranean countries. It usually consists of a mixture of cement or lime and sand, applied in one or more coats over a rough masonry or frame structure; the finish is either troweled, floated, or rough textured. The finish called roughcast or rock cast, formerly common in England and the United States, consists of small gravel or other pebbles mixed with wet plaster and thrown or dashed forcibly against a freshly plastered wall. In Italy a form of decoration known as graffito is often applied to a stucco wall. In ancient Greece a form of stucco was often used over coarse stonework to give a fine surface suitable for receiving detail. The Romans employed stucco similarly on external surfaces and, with notable success, as an interior finish; for indoor work they used a mixture of plaster of Paris or powdered marble, capable of receiving a high finish. The term stucco is also applied to various forms of interior decoration in relief that more properly would be classified as plastering.