A natural pearl and diamond pendant-necklace, circa 1930. Sold for £20,000 (€26,627). Photo Bonhams.

The drop-shaped natural pearl measuring 10.1 x 10.3 x 15.0mm, with rose-cut diamond cap, suspended from a pendant of geometric and scrolling design, pierced and set throughout with old brilliant and single-cut diamonds, with a central marquise-cut diamond within a single-cut diamond border, suspended from a fine adjustable chain, mounted in platinum, principal diamond approximately 1.10 carats, remaining diamonds approximately 1.75 carats total, pendant length 4.8cm

Accompanied by a report from The Gem & Pearl Laboratory stating that the pearl is natural, saltwater. Report number 09240, dated 14 January 2014.

Bonhams. FINE JEWELLERY, 30 Apr 2014 14:00 BST – LONDON, NEW BOND STREET