National Geographic : 1903 Dec
456 THE NATIONAL GEOGRAPHIC MAGAZINE From George F. Kunz, U. S. Geological Survey Diamond Sawing by a Process Recently Invented by an American The diamond is held firmly and very steadily under pressure against a rapidly revolving disk of sheet iron or "phosphor" bronze. The wheels are much like those used in sawing thin sections for microscopic rock sections or for cutting jade, rock crystal, and other hard stones. It is claimed that in thus dividing an octahedron at the center or girdle as little as 2 per cent of the weight of the crystal is lost-a great saving of material. As evidencing the wonderfully keen responsive business acumen which has always characterized the "rough " syndicate, the price of all rough diamonds that could be improved or advanced in value by such sawing was immediately advanced when the process became known.