In the 16th century, an alchemist invented Undine - also sometimes spelled "Ondine" - a mermaid-like character associated with water. They were always female, and were known to have beautiful singing voices. Sound familiar? Hans Christian Anderson borrowed from this legend for "The Little Mermaid". On this high-carat locket, we see the water nymph's name along with a flag which almost certainly has significance - Lindsay thinks Undine was the name of a ship. It's in incredible condition, with flawless enamel, an intact glass lens, and the original fitted box which says Page, Keen & Page Goldsmiths Plymouth. This was a major port so they probably specialized in nautical jewelry.