There is an famous eye doctor who uses flint blades to operate with, in it's sharper than steel and he likes them more than Lazer.
I read an article where a flint knapper...an Antropology professor, gave a flint knife to a professional guide/skinner, and the man couldn't handle such a sharp blade on his first try.
If you knapp you got to wear not only safty glasses but a breathing mask. Knapping is dangerouse to your lungs.