Antique Enameled Blue Triangular Etched Copper (?) Locket Pendant

Unique and wonderful antique copper (or copper colored metal) triangular locket pendant with robin's egg blue enamel and light etching on front. Enamel is in great shape, with no loss. Tough to tell what the etching is/was, but it now looks simply floral-ish. Adds to, rather than detracts from, the look. Still has both photo guard covers inside.