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.
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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