A sapphire and diamond ring

A sapphire and diamond ring, mid 18th century, of 'toi-et-moi' design, collet-set with a circular-cut sapphire and a rose-cut diamond in foiled silver settings, the openwork shoulders accented by rose-cut diamonds, mounted in silver and gold, size O, later shank with assay marks

Cf.: Diana Scarisbrick, Rings: Jewelry of Power, Love and Loyalty, London, 2007, pg.256, no. 353 for a ring of similar design, dated circa 1760