Those are really interesting. They look to be slate or shale not sure though as i do not have them in hand. They look like some sort of tablet stones. If you look closely they have intricate designs on them. The one that has hafting grooves in it looks like it has human petryglyphs on it as well as deliberate lines. The other one as well. The other one doesn't have the human petryglyphs. I would venture a opinion on a Tablet stone telling some kind of story. Look at them closely. They have some sort of meaning to them. The one that has hafting grooves looks like it was a old axe or something........................JMO...........................GTP