Natural Sharpening Stones From Belgium
The Ardennes region of Belgium has for centuries quarried natural stones famous as high quality whetstones. Sought after by Straight Razor Sharpeners, Woodworkers, Carvers and Leather Workers, these natural stones are not as abundant as they once were. A single quarry is still in operation in Belgium hand producing these wonderful natural sharpening stones.
Belgian Blue Stones
This particular type of whetstone is called a Belgian Blue Whetstone, or BBW for short. Characterized by a high concentration of spessartite garnets, the BBW's have a blueish-purple color caused by the presence of iron in the stone. They are known for being of very uniform quality and working quickly. Of course, as they are hand shaped natural stones, some variance of size and exact composition is normal.
A Unique Sharpening Experience
If you are used to using modern synthetic or even natural Arkansas stones, you will find sharpening with a Belgian Blue to be a bit different, but very satisfying.
Single Stone Sharpening
While they are often compared to Japanese water stones of 4000 - 6000 grit, BBW's can actually be used as if they were multiple stones of varying grit. Altering the amounts of water and pressure used while sharpening will make the stone more or less aggressive.
Coarser sharpening is achieved by using less water and greater pressure. The garnets in the stone break free and create a slurry when used in this fashion. In the slurry created on a BBW, the hard garnet particles are able to abrade more deeply as they roll freely on the surface of the stone, resulting in a more aggressive action that will leave a cloudy finish on the metal.
You can achieve an even finer sharpening by reducing the thickness of the slurry and by gradually adding more water and reducing the amount of pressure used. Eventually, the slurry is thinned to the point where only water will be present on the surface of the stone. With fewer garnets rolling freely on the surface of the stone, the individual particles cannot bite as deeply. At this point, using almost no downward pressure on the edge against the stone, the result is a mirror-fine finish on the metal.
Belgian Blue Whetstones are found alongside and are related to Coticule Whetstones. While each type is often used as a stand alone sharpening stone, they are sometimes combined, the BBW being used for initial sharpening, and the Coticule being used for fine finishing.
Use With Water
Belgian Blue Stones should only be used with water, never oil. They are non-porous and do not absorb liquid or clog with swarf, so there is no need to soak them prior to sharpening.