I think most knapperes would be curious about other materials, especially local stone. I wonder how many of us are able to collect materials rather than purchase them? For instance, I can collect Crowley's Ridge (Lafayette Gravel) any day I want (barring flood times) and I don't know of it being for sale anywhere. Might be a great trade for someone. That said, I'd risk a swap for lord knows what just to see what I get. What about heat treating? I think as long as we knew what to do as instructed by the trader, anyone should be able to crank up a Turkey roaster and some folks like raw rock. It would be a gamble, and not applicable to everyone, but some folks with lots of local rock might be interested. I would be for medium box rather than large though.