A few decades ago, American Barbers' organisations distinguished several stones. Dark colored waterhones, with a grey or clay-like appearance, producing a very fine edge, used with a rubbing stone that created a fine polishing sludge. The Belgian oil stone, top-light and mounted on a dark base, or bicolored ones cut from one piece of light rock and adjacent alkali deposit rocks. They cut slightly faster than the water hone. Synthetic hones, the oldest of which was the Austrian Swaty, a medium fast cutter, causing rapid overhoning in the hand of the unexperienced.
Present hones are natural or synthetic and can be used dry, with oil or water.
Fine and very fine natural stones widely available are the Arkansas, Belgian, and Japanese water stones. They are quarried and cut and polished into the preferred size. Most natural stones quarried in the 19th century were good. Particles were densely packed and highly regular. The figure shows a magnified natural hard Black Arkansas stone with a cuboid inclusion body.