"Rock Tumbler grit", also known as "rock polishing grit", is a silicon carbide powder that is much harder than the types of rocks that are commonly polished within a rock tumbler. If it is tumbled in the barrel with rocks and water the abrasion caused through the grit particles rounds https://cdn-cgi-l-email-protectio60258.worldblogged.com/34779660/an-unbiased-view-of-silicon-carbide-thin-films