An emerald and diamond cocktail ring,

An emerald and diamond cocktail ring, claw set octagonal emerald, approximately 9.7 x 8mm, known stamped weight 3.40ct, surrounded by double halo of round brilliant cut diamonds, split diamond set shoulders, estimated approximate total diamond weight 1.60ct, 'D' shaped shank, size L½, hallmarked Birmingham, 18ct gold, weight 5.9g, cased