This one is a bit odd. It’s serrated one side, a blade on the other and broken on the 3rd. Did they ever make a point serrated on one side and a blade on the other?
I've seen an eccentric Montell from Tx that looks very similar to that one and so my buddy willjo has a good argument too. Check out Denticulate_tool...
It was in a tub of brokes I was given, I’ve been trying to id them and I do keep getting led back to Texas, which is where the guy that acquired them lived for a time so that’s def a possibility. Unfortunately he passed a few years ago so I can’t ask him.
It does very much resemble something that could be used as a pottery dentate stamp. I have a small one made of sandstone, but I imagine most were made of wood. I've seen one made by notching the curved edge of a quahog(hardshell clam) shell as well. Just a wild guess, the humps, or peaks, in that piece are not really even, so maybe a bad guess....