Sharpening Stone

A sharpening stone, also called a whetstone, is an abrasive tool used to sharpen the edges of steel tools such as knives and blades through grinding and honing. It is made from either natural quarried stone, typically quartz based minerals such as novaculite, or synthetic materials including silicon carbide, aluminum oxide, or cubic boron nitride. Stones vary in shape, size, and grit grade, with flat stones suited to standard edges and contoured stones for specialized blade shapes; the grit rating determines how coarse or fine the finish is, with higher numbers producing a finer edge. Stones are commonly used with a cutting fluid to lift away removed metal and reduce heat, and are called water stones when used with water, or oil stones when used with oil. Naturally occurring sharpening stones were documented in antiquity, including by the Roman historian Pliny in his Natural History, and Belgian Coticule stones have been quarried from the Ardennes region for centuries. Modern synthetic stones are generally considered more consistent than natural stones because their abrasive particle size can be controlled precisely.