I rarely work obsidian and glass now because I do cut myself more often with it, and mistakes on it are more often disastrous. Also, I almost always end up with a piece that is entirely pressure flaked when I use obsidian or glass. Those patterns are pretty, but I like more variety. Basalt seems to be slightly tougher, and mistakes on it are less disastrous. That's just my take on it. A lot of knappers, especially west coast knappers, prefer obsidian over everything else.
WA
