A spinel single-stone ring. Photo Bonhams.

The cushion-shaped spinel, weighing 8.50 carats, between oval-cut diamond shoulders, ring size N. Estimate £15,000 - 20,000 (€18,000 - 24,000)

Accompanied by a report from SSEF stating that the spinel is of Burmese origin, with no indications of heating. Report number 67324, dated 19 March 2013.

Bonhams. FINE JEWELLERY. London, New Bond Street, 30 Apr 2014 - www.bonhams.com