Just a couple of hours from the workshop, in Vielsalm, are some of the most well-known sharpening stone deposits outside Japan. The geology of the Ardennes is primarily composed of shale, and while a few quarries remain active, many closed during the last century. On a recent visit, we explored abandoned sites and collected samples of various shales, slates and metashales. Some of them for sharpening, others for polishing.