>>2473776Sort of.
So far I've snapped 2 of the flakes halfway through working them.
But it shows that you need to think of flint not as glass, but as an extremely brittle piece of rubber. If you put any appreciable bending force on the flake, it'll snap. This means blows with a hammer stone after you've made a flake are absolutely haram.
Both breakages were caused when I got impatient with the pressure flaker and tried to spall off larger flakes with a hammer stone.