My bud in Warsaw MO can walk out in his yard and pick up what he/they call "ozarkarite"( right or wrong? ) .. I think it's the state rock??
anyway, he brought a small bucket full to a rondy we were at and asked me to try and knap some flints. A lot of them were
grainy and veiny .. one whack and they'd shatter. I
was able to work him up a handful of useful flints. He swears he is still
using the first one I handed him??? just remember they sparked like all get out.. against a fire steel or in his lock..
oh , we put a few chucks in the coals of the campfire over night.. to try the heat treat?? most just crumbled into gravel..
Respect Always
Metalshaper/Jonathan