An early 20th century natural pearl and diamond necklace, circa 1915. Estimate £8,000 - 10,000 (€11,000 - 14,000). Photo: Bonhams.

The double row of 138 graduated natural pearls, measuring from 3.9 to 6.8mm, the lozenge-shaped clasp set with a marquise-cut diamond and old brilliant and baguette-cut diamonds, principal diamond approximately 1.75 carats, length shorter row 40.0cm

Accompanied by a report from GCS stating that the pearls are natural, saltwater. Report number 5775-1930, dated 8 May 2015.

Bonhams. FINE JEWELLERY, 24 Sep 2015 12:00 BST - LONDON, NEW BOND STREET