Originating in ancient India, a poison ring (also called a locket, pillbox, casket, socket or box ring) is a type of ring with a container under the bezel or inside the bezel itself. They replaced the practice of wearing keepsakes and other items in pouches or amulets around the neck and arm.
Used to carry items such as perfume, locks of hair, devotional relics, messages, pictures and keepsakes, locket rings were considered so useful that their custom rapidly spread to other parts of the world.
The term poison ring became popular during the sixteenth century when it was commonly believed that locket rings were used by the aristocracy to facilitate the poisoning of the food or drink of an enemy, or even the suicide of a ring’s owner in order to escape capture or torture.