Available in 1 lb and 5 lb bulk sizes, Kingsley North’s 500 Grit Aluminum Oxide is a softer alternative to 600 silicon carbide pre-polish for your lapidary needs. Kingsley North’s 500 aluminum oxide grit is used in the pre-polish stage of rock tumbling and other lapidary work, providing a very fine abrasive to create a smooth, satin finish before the final polish.