Ceylon is a prolific source of a great variety of gem stones, and cutting there is an old craft which has been practised for many centuries. It is largely in the hands of the Muslims. Primitive tools are used, and practice and observation are the teachers. It takes from ten to fifteen years for an apprentice to pass from the stage of cutting imitation stones to the cutting of the precious varieties. Simple hand-operated machines are used, and the fixed idea of retaining as much weight of stone as possible nearly always results in a detraction of the value of the stone when it leaves the island. This has led to many importers buying the rough stone direct instead of the finished material.
Generally, the cutting disc is a leaden plate, the edge of which is coated with an abrasive powder such as corundum or garnet, according to the hardness of the stone being worked. The plate is rotated backwards and forwards by a hand operated bow string, small stones being held in a specially shaped tool. A similar wheel, but of copper or brass, coated with a fine paste, is also used for polishing. Experience only guides the native lapidary; he uses no electric power, and apart from custom, he uses no scientific knowledge regarding the optical properties of individual stones.
We will now consider the actual forms of cutting, that is, the general shapes into which stones are cut so that their individual properties are best brought to light. At the same time, these shapes will best lend themselves to their application in mounted forms of jewelry.