A diamond single-stone ring, by Harry Winston. Photo Bonhams. 

The round brilliant-cut diamond, weighing 4.34 carats, between tapered baguette-cut diamond shoulders, signed Winston for Harry Winston, remaining diamonds approximately 0.40 carat total, mounted in platinum, ring size E 1/2. Estimate AU$ 250,000 - 350,000 (€170,000 - 240,000)

Accompanied by a report from the Gemological Institute of America (GIA) stating that the diamond is D colour, VVS1 clarity. Report number 2155652795, dated September 16th 2013.

Bonhams. FINE JEWELLERY. Sydney. 6 Nov 2013 19:30 EST