It's definitely an intriguing shape, however I've never seen one like that or made from that material. It is roughly worked, to the point that I'm not sure human hands had any intervention in its creation. I'm not saying it's definitely not an artifact, but my money is on a no. I've found several pieces in the fields of Ohio that are actually similar in shape but clearly weren't worked. if it were worked by any native Americans it would have a clean sharp pointed edge much like a modern Axe and you would see the knapping marks towards tthe edge. Just my opinion.