How was the very first diamond cut?

Because one needs diamond dust to cut a diamond, but how did we get the first diamond dust to cut more?|||Cleavage. A diamond will cleave if struck at the right angle in certain places. So you can cut it without having to match its hardness.|||Extreme pressure beneath the earths surface. Pressure that we cannot replicate on the surface.|||diamond are rarely cut: usually abraded by a disc impregnated with microdiamonds.