Description
This is a #10 size “La Grise” Belgian coticule bout (“bout” = polygon), bonded to slate. One axis has been aligned to a ~6.5’Ø form, with a ~25’Ø shape affected across its the axis which is 90° to the ~6.5’Ø-shaped axis. This stone is ‘pure as the driven snow’, and I don’t think by strata that you can find a better rock for this task, only by shape/size/depth. The entire surface of the stone is completely homogeneous and featureless/repeating, not easy to find that the bigger any stone gets.
There is a free included slurry/rubbing stone, which has been shaped concave to the bench stone. See the images for more information.
For the primary shape of your bevel, face the stone’s length toward the spine-to-edge axis of the razor, and rub it along the length of the cutting edge while aligned in that fashion to the razor. There is a 25’Ø axis *across* the stone, so as you rub, try to vary where you work upon the bevel, or move the contact patch across the bevel like a circuit. I detail these concepts below;