Fine moonstone with great blue schiller play of colour 10.5mm x 7.5mm with 0.80cts of old cut diamonds set in platinum and 18ct yellow gold. Head size 13.5mm x 11mm. Hallmarked and maker's mark RB&Co. Regnall, Bigney & Co. Attleboro MA. U.S.A circa 1900 Currently finger size K 1/2 (U.S 5.5)