Holy mother of....
I made my best effort at "spalling", first with the billet then with a soft hammerstone.
With the billet I only threw short flakes from the edge, and the hammerstone didn't do any better before splitting in half.
The tine worked great on glass for jackcrafty 's style of indirect percussion, but bounced right off of the quartzite flakes, or snapped them half.
I need to find better stone...
And a bigger, fresher billet