High Quality Content by WIKIPEDIA articles! Ashlar is prepared stone work (i.e., dressed, cut) of any type of stone. Masonry using such stones laid in parallel courses is known as ashlar masonry, whereas masonry using irregularly shaped stones is known as rubble masonry. Ashlar blocks are rectangular cuboid blocks that are masonry sculpted to have square edges and smooth faces. The blocks, in European masonry, are generally about 35 centimetres (14 in) in height. When shorter than 30 centimetres (12 in), they are usually called “small ashlar”.