NOTE: Stone shown is a stock photo. These are natural stones, so their appearance may vary slightly from the photos shown.
The Belgian Blue Whetstone is a natural sharpening stone from the atelier of Ardennes Coticule, the only remaining producers of these sharpening stones. These hones are mined alongside yellow Coticule stone, and are somewhat similar in their sharpening abilities but with less cutting power so are a bit slower and not as capable for coarser work such as bevel setting on razors. They are better thought of as mid-range and finishing stones and excel at that purpose.
This Belgian Blue Whetstone is a small approx. 40mmx40mm x 15mm thick stone meant as a rubbing stone, or slurry stone for making an abrasive slurry on larger BBW hones.