Went for a quick rock run yesterday just to see if we could find anything in the dry creeks around home. We kept coming across this rock that is somewhat knappable but not. It weighs a ton and is all over the creeks with large sandstone, geode, and a little bit of chert deposits. We are in Southern Indiana.......someone mentioned basalt? Anyone have any ideas? I am gonna try to make a point out of it and try cooking some to see if it changes anything.