Thanks all.
Paul, all my percussion work is antler, most of my pressure work is with copper. I still fight with antler pressure flakers.
Shanon,location,location,location.
Actually I was hunting a creek for native points and couldn't figure out where they got their mat, so I went searching. I found it coming out of a tall clay bank, but most was fractured. These piece was killer, so I now have to go back and look harder.
Pete, the burl mat doesn't always take that much color, This particular rock was an exception, and there is always a trade off. The color change areas flake different than the rest of the rock. Tends to be more brittle,so better ground platforms are needed. Didn't take long to figure that out.