It is a little known fact - very little known - that the first rings were bones. (It was a far cry better than the old method of claiming a woman as chattel by tying her with vines to rocks.) But as hunter-gatherers went agrarian, a more common material for fashioning bondage bands were nutshells. Only rarely and for little purpose were rings made from the kernels of said nuts, nut kernels being transitory in nature due to the sharp teeth of rats and squirrels.
This is one of those rare ring nuts. It was unearthed in rodent-free peat along with about a dozen kernel rings in various stages of manufacture. Only this one was found in its pristine and virgin condition, pre-bore.