This is an old, old tool. Millions of years old. This is a 5x shot of the business end of it.
The tooth is from a megalodon, and is about 6 cm long. It isn't especially sharp, which is sort of too bad. I was hoping to see how a razor edge on a tooth would show up. I also have a smaller shark's tooth that has a sharp point, but the problem is hanging onto it for the photo. It isn't very big.