"Rock Tumbler grit", also known as "rock polishing grit", is really a silicon carbide powder that is much harder than the types of rocks that are commonly polished inside a rock tumbler. If it is tumbled inside of a barrel with rocks and water the abrasion caused via the grit https://siliconcarbidesupportroda37935.pointblog.net/the-smart-trick-of-recrystallized-silicon-carbide-plate-that-nobody-is-discussing-70221275