Victorian 18ct Gold & Black Enamel Round Locket

A slim 18ct75% pure gold (or 750 parts pure gold and 250 parts other metals) gold locket that opens to reveal a glazed compartment that would originally have held a lock of hair. It has also been engraved  ” F D Aug 13. 1854″ with a coronet above.  The outside has been enamelled in black enamelA pigmented glass-like material used in powdered form and fused onto the metal surface of a piece of jewellery. on both sides with stylised leaves. The opening and closing mechanism is ingenious as you fold the top loop down then press down on the spigot and it springs open.