Piece of hard, coarse-textured stone, capable of being broken into thick, flattish pieces, the commonest types being Kentish rag (tough, hard limestone, readily broken into usable pieces), Rowley rag (a basaltic stone from Staffs.), and other stones, notably in the USA. Rag-stones are not laid in regular courses, and mostly used as facings to brick or other types of stone wall. The appearance of a rag-stone wall is net-like, formed of a pattern of approximate polygons, with the mortar joints coarse (rough-picked) or fine (close-picked). Kentish rag is commonly found in C19 Gothic Revival churches in London and the south-eastern counties of England. Rag is also used in rubble walls.
W. McKay (1957);J. Parker (1850)