Emerald and Diamond Oval Cluster Ring, Central Emerald cut Emerald weighing approximately 0.50cts surrounded by 10 old european transitional cut diamonds (approx 1ct) set in platinum and 18ct gold, English circa 1900. Head size 13mm x 12mm (0 33⁄64 inches x 0 15⁄32 inches)  Current size I (U.S.4 1/4) This can easily be sized by my Goldsmith.