One Critical variable to recall is that silicon carbide is the preferred grit for rock tumbling. The popular grit for rock tumbling is silicon carbide because of its hardness and ability to wear down and smooth out the rocks effectively. Safety Data Sheet according to Regulation (EC) No. 1907/2006 (Attain). https://emilianowvsom.bloggazzo.com/28446354/the-smart-trick-of-recrystallized-silicon-carbide-plate-that-nobody-is-discussing