I am pretty certain this antique Battersea enamel medallion once had a post with threaded end on the back, so to be used as a curtain tie back or similar, but at some point that was removed, meaning now it could easily be turned into a brooch, or framed, etc. (I have found one exact match of this one out there with the post still in tact, selling for $445). I really love this woman leaning on large anchor, who I believe is meant to represent the Goddess of Hope--making this a bit of a good luck charm I would say!
Battersea enamelware is a type of painted enamelware considered the finest of its kind to be produced in England during the mid-18th century, especially noted for the high quality of its transfer printing. This ware is composed of soft white enamel completely covering a copper ground, with the design applied to the white enamel by transfer printing--a process by which an impression from an engraved metal plate brushed with enamel colours is transferred to paper and then to the surface to be decorated. Transfer printing was used on a large scale for the first time at Battersea.
1 15/16" in diameter and in very good overall condition, with a couple of dark lines along the right edge, what looks like a little fading to a couple of sails on the ship at left, and a little dirt around the edges where the metal meets enamel. I have not touched the metal or enamel on this but think it could be cleaned a bit if desired.