This is a selected coticule, cut from clear creamy coloured veins that have minimal cosmetic inclusions and comes bonded to a non-sharpening supporting layer of shale. They don't necessarily cut any better than standard stones, but are both rarer and more desirable - so the price is a little higher.
We supply each coticule with its own natural slurry stone, which works like a nagura to open the surface and raise a creamy slurry of sharpening grit.
What grit is coticule? In terms of where it fits into your sharpening regime, the answer is 4000 - 10,000 depending on how you use it. Each piece of natural coticule has it's own individual characteristics, before very long you won't worry about grit numbers and will instead be concerned with technique - the interplay of slurry thickness and pressure to get the desired result from your particular stone. At the two extremes, slurry with the consistency of double cream and moderate pressure gives the fastest cut, water only and the lightest possible touch gives the finest polish. Using your slurry stone and spray bottle to manage the consistency and progressing through double, single, full cream, skimmed milk and water with progressively lighter pressure at each stage is the equivalent of working through the grits. The slurry will eventually blunt with use (how quickly this happens will vary from stone to stone) so rinsing the surface periodically and raising a fresh slurry will keep your coticule cutting efficiently.
Flattening: Natural stones have softer, more rounded grit particles than man made ones, so dressing a natural stone with a man made one temporarily reduces its efficiency. The surface can be restored by rinsing and dressing the surface with the natural slurry stone and it is good practice to maintain the small 1-2mm wide bevel on the top edges to strengthen them. Good technique, using as much of the available surface as possible, will prevent the stone from becoming dished so you won't need to flatten it as often.
Dimensions: 200mm x 75mm x depth approx 20mm - may vary a small amount
Supplied with a beech and birch ply storage box plus a natural slurry stone
Image for example only, stone and slurry stone will vary slightly.
