Set with a cushion-shaped sapphire weighing 16.57 carats, decorated with calf-head-cut diamond weighing approximately 1.20 carats, mounted in platinum, signed Winston. Ring size: 7½. 

Accompanied by Gübelin report numbered 16075112, dated 11 August 2016, stating that the 16.57 carat sapphire is natural, of Sri Lankan (Ceylon) origin, with no indications of heating. 

Sotheby's. Magnificent Jewels & Jadeite Hong Kong, 04 Oct 2016, 02:00 PM