Silicon carbide is one of the hardest-known materials with a Mohs Scale hardness of 9+. This hardness gives it the ability to cut tumbling roughs such as agate, jasper and petrified wood, which have a Mohs hardness of about 7.

Angular Particles:   When crushed, silicon carbide breaks into angular-shaped particles with sharp points and edges. This gives it an effective cutting and grinding ability when it is caught between tumbling rocks in tumbler barrel.

Inexpensive:   Silicon carbide is inexpensive, selling for just a few dollars per pound as a screened and packaged product.

The combination of hardness, angularity and low price make silicon carbide an excellent abrasive for rock tumbling, gem cutting and lapidary work of all kinds. Silicon carbide granules are also used for sand paper, sand blasting, water-jet cutting and many other purposes.

via: https://rocktumbler.com/blog/what-is-silicon-carbide-grit/

My most precious ‘stony’s’

rough, unpolished, but totally fine grade 😸