Belgian shale

Yellow Belgian slate (Yellow Coticule) and Belgian blue stone (Belgian Blue Whetstone or as it is often abbreviated as BBW) are a rock of shale and sandstone. The special abrasive properties of this stone are provided by the high content of garnet in it. The special shape of the garnet crystals (dodecahedron in the crystal lattice) provides the high abrasive ability and high metal removal rate of the Belgian shale. But at the same time, the stone is worked very finely and cleanly and allows you to get an exceptionally sharp and blunt-resistant cutting edge. These unique properties of Yellow Coticule and BBW allow them to be used extremely effectively in finishing applications.

Yellow and blue Belgian shales are one of the most famous and, without exaggeration, the best natural abrasive stones in Europe, the high quality of which has been known to mankind for more than one century. Initially, only yellow Belgian slate was used for sharpening, while blue, which is harder, served as a reinforcing substrate for the relatively soft and brittle Yellow Coticule. When mining, the yellow coticule was cut along with the blue one, and thus two layers of sharpening bar were formed. Subsequently, these two stones began to be glued together, and having appreciated the cutting properties of Belgian Blue Whetstone, they also began to use it for sharpening.

These two stones work equally well on both carbon and chromium-containing and high-alloy (including high-speed) steels, they show excellent performance with Damascus and powder steels. They are used in finishing finishing operations, both when sharpening knives and for sharpening metalwork tools. But these stones have found the widest application for finishing straight razors, and in this application, Belgian shales are, of course, the best solution of all.