A tide-tossed, sea-tangled headdress for the siren caught in the current, barnacles and all, but not without its pearls. Coral was long worn in Ottoman and medieval Europe as a charm against the evil eye. Pearls are another kind of magic altogether: the sea’s quiet act of alchemy, something troublesome entering the shell and slowly being made precious. Across traditions, they have stood for purity, rarity and beauty.