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DIAMOND MINING                    217
jadi " and are worn as found. Diamond cutting is done at Pontianak, Martapura and elsewhere. The art has been practiced in Borneo for centuries. There are two shops in Martapura, one employing 2J0 and the other about 150 workmen. Besides these about 300 polishers and 160 cleavers work independently. They are paid about fifty cents per carat for cutting brilliants, and about thirty-five cents for cutting roses. There are diamond-cutting establishments in Pagattam and Toenggoel also.
The diamonds are found in the beds of the streams of to-day, and also in the gravels of watercourses long since covered up. The miners sink shafts through the overburden and tunnel into the diamondiferous material in crude fashion, hoisting the gravel to the surface and washing it in about the same way as all others do who work in alluvial deposits. The Malays wash in a small bowl and show remarkable skill and keen vision, picking out with unerring rapidity diamonds so small as to escape entirely the observation of a European. The Malays mine and cut in the crude Oriental ways of ancient times, but the Chinese adopt some modern methods in their minĀ­ing operations. The cutting is done by natives.
The deposits .of the Landak district are older than those of the southeastern section around Martapura, but all the fields alike are remarkable for the number of stones of deep color they afford. Borneo has produced more diamonds, proportionately, of rare colors than any other country; red, green, black and deep rich brown. According to Dr. Theodor Posewitz, a mining engineer who resided in Borneo for some years, as given by E. W. Streeter in his work on Precious Stones, the natives have names by which they designate the most important.