A diamond and coloured diamond serpent necklace, by A Cooagnato. Photo Philips de Pury & Co

Designed as a serpent grasping its tail in its jaws, the long body articulated and engraved as snake scales and decorated with a line of collect-set diamonds, the head and tail pavé-set with diamonds and coloured diamonds to pear-shape diamond eyes, length approximately 57 cm, c. 1960s, signed ‘A. Codagnato’. ESTIMATE £55,000-65,000 - Unsold.

Philips de Pury & Co. Jewels. 1 june 2011. London www.phillipsdepury.com