Granite, an igneous stone. Marble, a metamorphic stone of limestone. Slate, a metamorphic stone of shale. A. Stone may be laid either coursed or uncoursed. Coursed stone is either worked, or free-stone that is tabular and capable of being quarried at regular thicknesses.
Coursed stone is either regular or irregularly coursed.
B. Stones that have been squared and finished are ashlar. Quions, are large ashlar stones used to reinforce the corner of buildings. C. Stones that have not been worked are laid in rubble walls. D. Stone was also important as paving material through the nineteenth century. Ward Lock limited, 1977.