What is this oilstone?
Bill Houghton, Sebastopol, CA
>The recent thread about oilstones inspires me to ask this group what is this oilstone I recently acquired (I can't call it rust-hunting...but it's sure bottom feeding: 75 cents). It came attached to one of those equilateral-triangle blocks of wood used with the Smiths "tri-stones," mounting three stones on one block of wood and (with a little stand) allowing you to flip stones around for sharpening.
It appears to be a coarse-ish stone of some kind, but I have no idea what it is. Anyone recognize it?