Sharpening stones, water stones or whetstones are used to sharpen the edges of steel tools and implements through grinding and honing.
Sharpening stones come in a wide range of shapes, sizes, and material compositions. Stones may be flat, for working flat edges, or shaped for more complex edges, such as those associated with some wood carving or woodturning tools. They may be composed of natural quarried material, or from man-made material.
Stones are usually available in various grades, which refer to the grit size of the abrasive particles in the stone. Grit size is given as a number, which indicates the spatial density of the particles. A higher number denotes a higher density and therefore smaller particles, which leads to a finer finish of the surface of the polished object.