I have been finding this stone around my home for quite some time. It's lacustrine silex , and it looks just like the famous silex of Grand-Pressigny that was traded all over europe in neolithic times. Beautiful, sometimes translucent yellow stone. But it doesn't knap like that at all, it's super though.
So for the first time yesterday, I heat treated some stone. In the oven, around 250 C / 480 f degrees, for 3 hours, just a couple of tiny shards. Then I tried it as soon as it had cooled
WHAT A DIFFERENCE!
That stuff is as easy as my very best flint! The difference is amazing, I would never have expected that. And it looks SWEET! I'll be over my pile of crappy rock today and put it all under the fire and see it turn to gold!