An early 20th century single-stone diamond ring. Photo Christie's Image Ltd 2014

The cut-cornered rectangular-cut diamond weighing approximately 6.36 carats, claw-set to single-cut diamond line shoulders and a plain hoop, circa 1920, finger size J. Estimate £80,000 – £100,000 ($133,920 - $167,400)

Accompanied by report no.1152960829 dated 5 March 2014 from The Gemological Institute of America (GIA), stating the 6.36cts diamond is E Colour, VS2 Clarity, no fluorescence

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