Finally feel like I got a handle on this rock cooking thing. I went over to a creek in western Illinois and picked up a couple buckets of decent stuff and figured I'd give it a try this last week. Wife and I went on a camping trip last weekend and I took some raw stuff. It worked ok and I was able to make some points, but after pecking around on this cooked stuff the difference is pretty obvious.
Did this in the ground and built a fire over it with hard wood. Went at it a little slow so I wouldn't heat it too fast, but after I had her warmed up I really poured it on! After letting it cool for a day I started opening it up and only had one that shattered. The color change was impressive. Not striking colors like horse creek or that stuff that Tim is working with, but I like it knowing where it came from and how it came to be.
The 2 on the ends are treated. The second from the left is a piece I got from Tim (can't remember the name,) and the third is uncooked.