|a small often synthetic diamond, valueless as a gemstone, used in cutting tools, abrasives, etc|
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.
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