I'm from the uk so I think this stone might be too. I think its a natural stone. Its a soft stone thats dark gray almost black. I've lapped it to 600 on wet and dry paper.
http://i1295.photobucket.com/albums/...psfe4744b7.jpg
http://i1295.photobucket.com/albums/...ps07da0c5b.jpg
The bottom.
http://i1295.photobucket.com/albums/...ps91515919.jpg
http://i1295.photobucket.com/albums/...ps00f70a1c.jpg
I was told to post here by UKRob on another forum.