FREE: unusual old ring must c, can't explain it! lol

The listing, unusual old ring must c, can't explain it! lol has ended.

hi, this is such an unusual ring. i got it at an estate auction a long time ago, and fogot about it, until i found it today. lol.
the ring as you can see has 2 moveable circles attached to its side. The center of the ring on the top is a circle of balls with a bigger one in the middle, it almost looks like the top should open but it doesn't. This sides are nicely detailed and almost remind me of a marcasite look. I honestly don't know how to explain this and am hoping that the pictures will tell you enough. It is bigger, measures about a 9 1/2. I have no idea what this is made of... There are mo markings of any kind that I can see on this....You can see in the one pic, that the under side has some green there, I think it needs a good cleaning but i dont clean older things. If any of you know anything about this, feel free to let me know. It is looking for a new home! thanks and have fun!