Sapphire and diamond cluster ring, circa 1890. Sri Lanka has been the primary source of sapphires since at least the 2^nd century, and the island’s gem industry was recorded by both the 2^nd century writer Ptolemy and the 14^th century explorer Marco Polo, giving the island its title of ratna-dweepa, or the ‘Isle of Gems’. Sri Lanka produces sapphires of varying shades, including pink and yellow varieties, but the best known are its blue sapphires, with their distinctive, soft hue often described as ‘cornflower’. The Sri Lankan sapphire at the centre of this ring weighs just under 5 carats, but looks even larger thanks to its relatively shallow proportions, and displays this famed cornflower blue entirely naturally, without having undergone any heat treatment. Finished with a late 19^th century border of antique circular-cut and cushion-shaped diamonds, this is a superb example of a traditional sapphire cluster ring.