Ever since the first buildings were constructed with slate walling stone, slate quoins (corner stones) have been used to give structure and stability to the corners of buildings. Slate quoins are produced with the riven face vertical to the building façade, unlike slate walling stone where the riven/cleavage face runs horizontally into the wall. Having the cleavage face vertical allows the quoins to be a larger format than the walling stone units giving a sense of scale and solidity at the corners.
With the riven face vertical, the ends of the quoins cannot be riven and so it is traditional to ‘pluck’ one edge in order to create a natural looking end, avoiding a visible sawn finish. Today, with slate walling stone built typically as a 200-250mm facing to blockwork, rather than a solid 750mm thick wall, corners can be formed using walling stone units without the use of quoins, however, continuing to incorporate Burlington Stone corner stones adds aesthetic detail to a corner and implies strength, permanence, and expense, all reinforcing the onlooker’s sense of a structure’s presence.
Similarly, Baycliff Limestone quoins are produced with a pitched finish to the face and one end to provide a traditional format and a holistic appearance to accompany the same Baycliff Limestone walling stone.