Description: Coloring Abrasive. It is sintered ceramic tumbling nugget with exceptional properties: hard, durable , and extremely dense. Principally used in burnishing applications, can also be used for light burr removal, radius formation, and is an effective driver for loose abrasives in cut and color operations. A3�s hardness, toughness and fine crystalline structure make it one of the best products available for developing lustrous, high color burnish on all types of ferrous metals, brass, and aluminum. Porcelain (140 lbs./cubic ft.)