In the pics you'll see some of its process, and then the finished piece. The white center is bone, as in cow's bone. Processed, carved, lapidated. That was my first as well.
The design is mine, by pure improvisation. I love to improvise, but after this, I wouldn't advise it for such an intricate piece unless you're a seasoned jeweler.
Bottom line: if you want to learn chemistry and physics the fun way, with some hair pulling in the process, I recommend you start with something intricate and bite a bit more than you can chew! =)