Industrial diamond, any diamond that is designated for industrial use, principally as a cutting tool or abrasive. In general, industrial diamonds are too badly flawed, irregularly shaped, poorly coloured, or small to be of value as gems, but they are of vital importance in the modern metalworking and mining industries. Their utility stems from the fact that diamond is the hardest natural substance known.
Industrial diamonds can be mined from natural deposits, or they can be produced synthetically. Among the naturally occurring diamonds, three varieties exist: ballas, bort, and carbonado.
Very small and poor quality stones are called 'industrial diamonds' and are used as the abrasive material on cutting wheels and drill bits, machine bearings, glass cutting implements, and grinding and polishing powders.