Welcome to B&B. Feel free to introduce yourself to the gallery when you have the time. Your geographical location can provide some clues as to identifying stones, assuming that the stone was sourced locally.
Top surface seems to be stained with swarf ridden oil. Underneath, looks like it could be a Washita, or further afield from one of the end pictures, perhaps a Turkey stone, although I'm inclined towards the former.
A guy comes here, makes one post, gets an identification, and is able to increase his profit on ebay with almost zero effort on his part.
Please look at who you would give advice to.