A 17.94 carats Colombian emerald and diamond ring, by Bulgari. Estimate £40,000 - 60,000 (€55,000 - 82,000).  Photo: Bonhams.

The octagonal step-cut emerald, weighing 17.94 carats, within a four-claw setting, within a double tier surround of brilliant-cut diamonds, diamonds approximately 5.00 carats total, signed Bulgari, ring size K (sizing band)

Accompanied by a report from SSEF stating that the emerald is of Colombian origin, with indications of clarity modification, moderate amount of oil in fissures. Report number 80766, dated 25 June 2015.

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