HEy Xin,
Yeah, I've used hardwood billets and they work great on tough stone like rhyolite and quartzite. I have an osage billet, but I know James Parker (robustus) likes dogwood. I watched him blast some beautiful, long flakes off some tough rhyolite at a knap-in a few years ago, and he was using a big dogwood billet. I also talked to a friend who's into experimental archaeology and he's been on digs where the indians left behind huge quartzite percussion flakes that looked like potato chips. The only way my friend could get flakes like that was by using a hardwood billet made of live oak. He told me that with tough stone you need to finesse it more, and use a softer hammer. Intuition would lead you to believe a harder hammer is best, but it actually isn't. I saw some of the points my friend made, and they were out of the toughest, grainiest quartzite I had ever seen. And they were BEAUTIFUL.
I always used to wonder how the indians here in Georgia made such beautiful points out of such tough materials like grainy quartzite, so I tried it with antler but the stone wouldn't cooperate. But as soon as I started using an osage billet, the stone magically started working better than it ever had before. My flake removals were clean, whereas with harder hammers I was having a lot of step fractures and crushed edges. The key to hardwood billets is that they must be considerably larger than a comparable antler billet. Because the weight of the billet is key, you will need a much larger wooden billet to attain that weight. Woods like hickory and dogwood are probably better than osage, but my osage billet works, though it's a bit small and light. I plan on making some larger ones in the future.
Good luck with it and let's see some pictures of your finished work.
