This locket/ pendant is not marked but it tests to 9k ( acid test ). The engine turned design is on the front while the back is plain. The inside opens to reveal a compartment with a hand engraved grate lid to which one would insert a piece of perfume soaked sponge or cotton. Condition is good with some minor dings and dents to the locket body. The hinge is quite worn but still is holding. The body is 1 inch across. C. 1820 and English.