Wow, just checked out all the posts on this thread, and looked at the links hoping to see what unobtainium looks like. Heaven help me, I might HAVE one! When I bought a box of old jewelers stones, and sold off the Special Stone (before I knew what it was) I kept the pretty green stone, because it had a deep gouge in the back, and I didnt think anybody would want a damaged stone. Now I have to dig it out and lap it, just to see!