Diamond stones are made by bonding industrial diamond powder or pieces to plastic or steel. They cut quickly, are long-lasting and use water for lubrication. Diamond stones do not need flattening. Coarse-grit diamond stones are used to flatten water stones and oil stones.
Hard Ceramic Stones
Hard ceramic stones are made from a hard aggregate of aluminum oxide. They are durable and considered “lifetime” stones if cared for properly. These stones use water for lubrication, but can be used dry. India stone is an example of a hard ceramic stone.
Oil stones are fine grades of whetstones that use honing oil for lubrication. They are commonly in bench form, and most of them come from sedimentary, microcrystalline quartz, called novaculite. Oil stones are durable and need only occasional flattening. Stones of this type include Arkansas, Ouachita or Washita stones from Arkansas. Oil stones that are very fine grade are called polishing stones. Oil stones can be messy to use.
Water stones are traditional Japanese sharpening stones mined from sedimentary deposits. Water is the only lubricant that can be used on a water stone because oil can ruin a water stone. These stones are soft and sharpen easily, but they wear more quickly than other stones as they continuously break down, leaving new sharpening surfaces. Water stones must be flattened as they wear. Most of the quality, natural water stone supply is depleted, and remaining stones are costly. Man-made water stones made of abrasive particles (grit) bonded to resin or ceramic are readily available and less expensive. The abrasive particles of man-made stones are father apart than on oil stones, making them resistant to clogging and glazing. Soak water stones in water for 15 minutes before use.