A platinum single-stone diamond ring. Photo Christie's Image Ltd 2014

The pear shaped diamond weighing approximately 5.01 carats, to tapered baguette-cut diamond shoulders, raised on a plain hoop, London hallmarks for platinum, finger size L. Estimate £180,000 – £220,000 ($301,320 - $368,280)

Accompanied by report no.10115001 dated 3 October 2011 from The Gemological Institute of America (GIA), stating the 5.01 carat diamond is D Colour, IF Clarity, no fluorescence

Christie's. IMPORTANT JEWELS, 4 June 2014, London, King Street -http://www.christies.com/