Darnit! I cooked my first batch of rock this week with all the advice here for drying time and cook times and now I'm hooked! I cooked Texas rock from Seider's rock pile , local porous and grainy chert, and some buffalo river from , well , buffalo river. I am impressed with the improvement of knapping this new rock. That Texas stuff rocks! Going to have to get more when this runs out. I'm a fan of heat treated rock. No doubt the paleo people did heat treat from the artifacts I've found here and how the local chert knaps now since heat treating.
Tracy