An orange sapphire single-stone ring, first half of the 20th century. Photo: Bonhams.

The oval mixed-cut orange sapphire, within a four-claw setting, sapphire approximately 7.70 carats, ring size K. Estimate £6,000 - 8,000 (€7,300 - 9,700)

Bonhams. FINE JEWELLERY. London, New Bond Street, 30 Apr 2014 - www.bonhams.com