Cleavage surfaces are not perfectly smooth. One of them is cleaving. Most preliminary shaping of diamonds is done by sawing, which may be done with a thin, rapidly revolving phosphor-bronze disk. The edge of the saw is impregnated with diamond powder. Beginning in the late 1970 lasers came into use for sawing diamonds.
Laser cutting is significantly faster than conventional mechanical sawing.
The final step in completing the stone is faceting. The facets are ground and polished in a single operation performed on a revolving horizontal lap made of cast iron. Its surface is charged with diamond powder, and the speed of rotation is between 2400 and 3000 rpm.