Corundum is a mineral from the category of oxides and hydroxides and is the most frequently used industrial mineral worldwide. It also occurs naturally as a gemstone (sapphire, emerald, ruby). Chemically corundum is aluminium oxide with the chemical formula Al2O3.
Coarseness of the abrasive mineral:
Commonly referred to as “grit”, this number designation is determined by the amount of abrasive mineral that can pass through a mesh screen with specific size openings. Therefore, a 40 grit abrasive particle will pass through a mesh