Thread: UK Black slate hone

Purchased as a 'carpenters oilstone'.

Lapped it flat then progressed up to 5k grit sandpaper. Produces medium grey slurry - very smooth with a slightly shiny matt look.

Harder than Thuringian, but not as hard as Llyn Idwal/Charnleys. More slate-like and less dense.

Honing is very slick and produces a good finished edge that is quite smooth Thuringian-like.

Having trouble deciding whether it should come before or after my Thuringian.

Dimensions: 197 x 44 x 12mm

Any ideas for ID? Water of Ayr perhaps? Or Modine's Special Stone? Or the mythical Black Escher?

Similar to a hone Geezer posted about here