Jogtac, glad to have you and your son with us. Welcome aboard.
Your pieces are are all naturally fractured creek stones. Very common in most creeks.
There are are quite a few posts on here about Stone Tools. You can search by that or search by a members name. I have quite a few posts on Axes, Celts, Pestles, Hammerstones, Hoes, etc. Do a search on my name and check some out.
Dont give up yet. Do research on your area to see what materials and types you should be looking for. Get permission and try plowed fields after good rains as well as creeks. Good luck to you both and Happy Hunting!