A sapphire and diamond ring. Photo Bonhams.

The cushion-shaped sapphire, weighing 10.08 carats, set within an elaborate surround of marquise and brilliant-cut diamonds, diamonds approximately 4.20 carats total, ring size 6. Estimate HK$ 1.3 million - 1.8 million (€120,000 - 170,000)

Accompanied by a Gubelin report stating that the natural sapphire is of "royal blue" colour, has no indications of heat treatment and originates from Burma (Myanmar). Report number 13037276, dated 13 March 2013. Also accompanied by an appendix from Gubelin stating that unheated sapphires of this size are scarce.

Accompanied by a SSEF report stating that the natural sapphire has no indications of heat treatment and originates from Burma (Myanmar). Report number 58710, dated 8 March 2011.

Bonhams. FINE JEWELLERY AND JADEITE. Hong Kong, Admiralty, 21 May 2014 - http://www.bonhams.com/