I have a hunch this locket was made in America right after the Civil War, around 1870. All that abstract scritchy-scratchy background engraving? That texture appears on lots of American jewelry from that period. The woman who appears in the tintype inside looks like she has Seen Some $hit but wears some fantastic jewelry of her own. The center diamond is hypnotic.
MATERIALS: 14k gold (tests), 6 1.5mm rose cut diamonds, 2.5mm old European cut diamond, new 14k gold chain
AGE: c. 1870
SIZE: 1 1/4" length including the bale, 3/4" width, 18" chain.