A diamond single-stone ring. Photo: Bonhams.

The cushion-shaped diamond, weighing 3.14 carats, between channel-set square-cut diamond shoulders, ring size Q½. Estimate £16,000 - 18,000 (€19,000 - 22,000)

Accompanied by a report from GIA stating that the diamond is F colour, SI1 clarity. Report number 1152695655, dated 9th October 2013.

Bonhams. JEWELLERY. 12 Feb 2014, London, Knightsbridge - www.bonhams.com