Unknown stone, any thoughts on what it is?

[The*Cincinnati*Kid]

This stone came with my coticules & two razors that I got off ebay, and I was wondering if anyone can ID it for me or give me their thoughts on what it might be. I'm assuming that the previous owner used it on razors as it was with the coticules. Thanks in advance for the help.

Regards
Louis.
http://i942.photobucket.com/albums/ad268/cincinnati_photo/stone3.jpg?t=1306888561
http://i942.photobucket.com/albums/ad268/cincinnati_photo/stone1.jpg?t=1306889122
http://i942.photobucket.com/albums/ad268/cincinnati_photo/stone2.jpg?t=1306889179