A fine sapphire and diamond ring, by Harry Winston. Photo Christie's Image Ltd 2013

Set with a cushion-shaped sapphire, weighing approximately 7.92 carats, in a brilliant-cut diamond surround, 1958, ring size 4¾, in navy blue leather Harry Winston case. With maker’s mark HW for Harry Winston. Estimate:  $388,394 – $453,127

Accompanied by report no. 12100105 dated 23 October 2012 from the Gübelin GemLab stating that the sapphire is of Kashmir origin, with no indications of heating

Report no. 65432 dated 15 October 2012 from the SSEF Swiss Gemmological Institute stating that the sapphire is of Kashmir origin, with no indications of heating

Christie's. MAGNIFICENT JEWELS. 15 May 2013. Geneva. www.christies.com