I was on a smallish island in canada in the summer and had a few hours to kill while my dad was off in the boat fishing. (he grounded me and my brother to seperate islands, long story). There was a small granite rock, a bit smaller than a loaf of bread. I didn't have a wiki too look up how to make the stone axe (wiki =

Same kind of idea to make a few bone knives (really not durable, needed several to carve a cobra on a walking stick)
I think we should have a stone axe in cantr. I shouldn't double production, in fact, it should only have a slight increase, but even a slight increase, say 700 instead of 600, would be a help and cement it into a basic tool along the lines of bone knives and stone hammers.