An openable ring that is arranged to be worn about a portion of a body of a person. The ring includes first and second arcuate sections that are pivotally interconnected at one end of the ring for permitting pivotal movement of the arcuate sections between opened and closed positions. At the end opposite the pivotal interconnection, each arcuate section includes a pair of locking extensions, the locking extensions being transversely aligned with one another. Each locking extension has a locking surface which comprises a sum of more than two alternating hill and valley portions. The hill and valley portions of each respective locking surface cooperate with each other to releasably retain the arcuate sections in a closed position to define a closed ring having an inner surface and an outer surface. The inner surface defines an interior passage for receiving a portion of the person's body, e.g., a finger.