Mike_R, no joke about the welding gloves, huh. First time I tried knapping glass I made great progress with a copper flaker and a leather pad. After an awkward, wild flake I found something puzzling clinging to my point. Looked like a curly worm or something. Couldn't figure out what is was until I looked at my knuckle, which of course was dripping blood. Turned out I zinged a ribbon of flesh off of my knuckle and didn't even feel it. Healed really clean though!

This stuff fractures so sharp it's down to molecules in width.
To fire-harden wood, stick it in the dirt underneath your fire (no oxygen), not in it. You want it super heated, not charred. Not hard enough? Burnish it with a piece of bone or a really smooth pebble. Baseball players call this ham-boning I think.