quoin

One of the stones, alternately long and short, that make up the corner of a building or that form the sides of a window or doorway. They are often decoratively treated, and emphasised by making them project from the wall surface.

'Mackintosh Architecture' led by The Hunterian, University of Glasgow, funded by the Arts and Humanities Research Council; with additional support from The Monument Trust, The Pilgrim Trust, and the Paul Mellon Centre for Studies in British Art; and collaborative input from Historic Scotland and the Royal Commission on the Ancient and Historical Monuments of Scotland.