A natural pearl and diamond necklace, circa 1925. Estimate £6,000 - 8,000 (€8,200 - 11,000). Photo: Bonhams.

The single row of 77 graduating pearls, measuring from 8.4 to 3.5mm, with an old brilliant and baguette-cut diamond geometric clasp, diamonds approximately 0.30 carat total, French marks, length 43.0cm 

Accompanied by a report from The Gem & Pearl Laboratory stating that an extensive sample of pearls was tested and found to be natural, saltwater. Report number 10568, dated 10 December 2014.

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