Art deco solitaire aquamarine ring. An octagonal emerald-cut natural unenhanced aquamarine is set to centre in an open back half rubover setting with an approximate weight of 20.00 carats, to an ornate semi-circular and lattice shape openwork collet with flanking step down platinum rows to slightly raised curving supportive shoulders, and a conforming D-shape shank. Tested platinum, circa 1930.