Found in the back of a piece of furniture i recently purchased.

Found in the back of a drawer of a desk i recently purchased at a 2nd hand store. I found this single opal earing and a brass hand with MOP inset into it. i was very surprised at the quality of this opal to be set in just sterling? i think it's a very good [but small] piece of lightning ridge opal. I wish there were two! marked 925 on the back.