Here is a silicon carbide grinding wheel, 180 grit, meaning the average particle diameter is 82 micrometers. Silicon carbide is harder than aluminum oxide but is more brittle. Besides its use as an abrasive, it is also used as a semiconductor, brake disks, telescope mirrors, heating elements, jewelry, printmaking, and single photon sources, among others.
Equipment used: Canon EOS Rebel T5i with a standard zoom lens (EF-S 18-55 mm) on a 49 mm long extension tube.