One method of working various materials is to rub or grind them to achieve a desired shape, sharpness, or smoothness. Grinding or polishing is often one of the final stages in creating a product. The corrosive agents used to wear the surface of the product to the desired condition are called abrasives. In the past, many materials, from sand or dust to vegetable fibers, were used as abrasives. In more recent times, grindstones, grinding wheels and tools, and rubbing cloths and papers have all been employed. Natural abrasives include sandstone and solid quartz, emery, corundum, diamonds, and garnet. Manufactured abrasives include silicon carbide (Carborundum), aluminum oxide, boron carbide, synthetic diamonds, and boron nitride.

Silicon carbide was first manufactured in 1891 when Edward G. Acheson (1856-1931) heated a mixture of clay and coke. A former employee of Thomas Edison (1847-1931), in 1884 Acheson had struck out on his own in search...