Galleting, sometimes known as garreting or garneting,[1][2][3][4][5] is an architectural technique in which spalls (small pieces of stone) are pushed into wet mortar joints during the construction of a masonry building.
In sandstone buildings, the spalls are usually shaped into small cubes about half an inch in diameter and are flush with the stone.
[1][8] Scholarship has also suggested that galleting was neither a structural nor an aesthetic practice, but rather a superstitious one in an attempt to protect a building from witches and other evil influences.
[1][8][12] Given that these locations are not contiguous, much has been debated about the origin and spread of the practice, with some attributing its geographical prevalence to the particularities of the stonemason trade.
[4][5][8][10] Historical records indicate that parts of Windsor Castle (n.d.), Eton College (c. 1441), and the Tower of London (c. 1514) were galleted with flint or oyster shells.