"Rock tumbler grit", also known as "rock polishing grit", is actually a silicon carbide powder that is much harder than the types of rocks that are commonly polished in a very rock tumbler. If it is tumbled inside a barrel with rocks and water the abrasion caused from the grit https://silicon-carbide-cantileve69369.daneblogger.com/28488378/not-known-details-about-silicon-carbide-heating-elements-technical-data