A couple of rings I made this weekend using some of the internal skeleton of a prickly pear cactus pad that I had gotten from Curtis Seabeck several years ago. I took the ring blanks, inserted the cactus into the groove and then filled in with UV resin and cured with a UV light. One ring was painted lack, the other blue. With the use of UV resin, the possibilities are endless of what you can do.
Bobby
Louisiana