Well, "rare." All of the things mentioned already are certainly gorgeous, but I wouldn't call any of them "rare." These things can still be found if you really work t it, but it's getting harder and harder to find good pieces: jet-black ebony; Honduran rosewood burl; good, deep red bloodwood; snakewood. In addition, Hawaiian koa isn't exactly hard to find, but WOW it's gorgeous. I'd look at that too.