Who says jewelry has to feature a precious stone–or that it's got to be mounted in silver, gold or platinum? Each of Anna Rabinowicz's Ondo rings is cut, shaped, polished and designed to be all of a piece, so the natural material–Brazilian agate–is all you see. Rabinowicz has even left a rough face on each ring, for an effect that's sleekly contemporary and ancient as the earth. You'll find a selection at Rabinowicz's website, RabLabs, along with other (naturally) beautiful accessories.