Silicon carbide abrasive grain/grit size 80LG (lapping grade) is a course grade lapping quality grit but also good to use as the first grit stage for tumbling hard agates, jaspers, etc. (Coarse grit stage.) Remember to add 80LG grit weekly in your rotary or barrel tumbler since 80 grit breaks down quickly. Use one tablespoon per pound of rock in your barrel tumbler. Other uses for 80LG grit are in vibrating laps, flat laps, sphere machines, faceting, etc. The price listed is for a one pound package of 80LG silicon carbide. See articles on barrel or rotary tumbling, vibratory tumblers, and lapping procedures if you have any questions.