A natural pearl, diamond and sapphire cluster ring, circa 1960. Photo: Bonhams.

The drop-shaped pearl, measuring 11.1 x 12.95 x 16.0mm, within a border of marquise-cut sapphires and brilliant, baguette and tapered baguette-cut diamonds, diamonds approximately 1.20 carats total, ring size K (sizing band). Estimate £15,000 - 20,000 (€18,000 - 24,000)

Accompanied by a report from AnchorCert stating that the pearl is natural, saltwater. Report number 20014871, dated 8 March 2014.

Accompanied by a report from The Gem Testing Laboratory stating that the pearl is natural. Report number 110406, dated 16 February 1984.

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