Here is a mystery hone from a friend.
There is a chance this is a US born stone. After a few emails, I've found 3 other examples. 2 in the US, 2 in the UK but all acquired in the US... interesting
My guess is it's a slate.Seems to have good abrasive power, yet still very fine. I've tested it and would say the shave the edge produces is similar to a coticule.
A similar stone pick up but a guy in at a stone near Kentucky Lake
