That's awesome! I've been told, though haven't verified it personally, that an obsidian blade can be made with an edge as fine as a single molecule. I don't know if that's completely true, but I can say that they are ridiculous sharp. I haven't tried to shave my face with one, but I have shaved a little bit of arm hair off to test an obsidian edge, and it produced less resistance than my (at the time) Mach 3.