Oh, that's good stuff. I feel your pain on the quartzite point. I recognize that grade of the material. The whitish areas where the flakes tore as they came off is the tip off. Super tough, you almost need dynamite to initiate the flake, at the outside edge of what can be called knapable stone. Oh, and it looks like is has a knot (tougher area yet, flakes just bounce off) in the center.
Keith