Hiroshi Kure is a Japanese sculptor with a passion for skulls and resin composites that look like natural materials. There is a lot of skull paraphernalia out there these days, but these rings are the most exciting I've seen so far. He has made them in silver as well as this resin composite, and has even enameled a few in pastel colors just for a little humor. Available at Odin, one of my favorite shops in NYC.
Even if you don't like skulls, check out his site. He has used the same resin material and texture to create other interesting objects including some funky aviator glasses (picture after the jump).