gold ring with sapphire and diamond

A superb 18 carat gold French turn of the 19th century cluster ring with an emerald cut light blue unenhanced sapphire from Sri Lanka (app. 5.13 carat)  surrounded by 14 old cut diamonds and two on the side of the shank (app. 1.5 carat) set in platinum, France, circa 1890.

weight: 8.35 grams
ring size: 16.5+ mm / 6 1/4 US
width: 19.3 – 2.5 mm