A 9.05 carats diamond single-stone ring, by Harry Winston. Estimate £250,000 - 350,000 (€340,000 - 480,000). Photo: Bonhams.

The pear-shaped diamond, weighing 9.05 carats, within a five-claw setting between tapered baguette-cut diamond shoulders, maker's mark for Jacques Timey, ring size J (sizing band), Harry Winston pouch

Accompanied by a report from GIA stating that the diamond is D colour, VS1 clarity. Report number 5171045782, dated 2 March 2015.

BONHAM'S. FINE JEWELLERY, 22 Apr 2015 14:00 BST -LONDON, NEW BOND STREET