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

The pear-shaped diamond, weighing 9.97 carats, between tapered baguette-cut diamond shoulders,signed Winston for Harry Winston, remaining diamonds approximately 0.70 carat total, mounted in platinum, ring size J. Estimate AU$ 380,000 - 480,000 (€260,000 - 330,000)

Accompanied by a report from the Gemological Institute of America (GIA) stating that the diamond is G colour, VVS2 clarity. Report number 2155652784, dated September 16th 2013.

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