This Kingsley brand large grit kit contains 5 pounds each of 80, 220 and 600 Silicon Carbide grits, plus 1 pound of Mirco Alumina Polish compound. This kit will polish 34 to 40 pounds of stone. DID YOU KNOW? The Chinese are thought to have been the inventors of the very ingredient that makes modern rock tumbling practical — silicon carbide abrasive. Ordinary sand wears out. Individual grains lose their sharpness and cutting edges or eventually pulverize into powder. The Chinese crystal and jade polishers discovered that sand on which a fire had been built kept its abrasive qualities much longer than ordinary sand. They were soon firing sand and charcoal in kilns to obtain larger quantities of the new abrasive, a form of silicon carbide. Most of the sharp, long-lasting grits used in rock tumbling today are variants of this ancient material.
