Lot 60. Fine 10.85 carats Octagonal Step-cut Columbian Emerald and Diamond Ring. Estimate HK$3,500,000 - 4,500,000 (US$450,000 - 577,000). Courtesy Tiancheng International. 

Centring on an octagonal step-cut emerald weighing 10.85 carats, to a stylised basket decorated with brilliant-cut diamonds extending to the shoulders, the diamonds together weighing approximately 1.05 carats, mounted in platinum. Ring size: 5½

Accompanied by Gübelin report numbered 12030263, dated 2 April 2012, stating that the 10.85 carat emerald is natural, Green colour, of Colombian origin, with no indications of clarity enhancement; 

SSEF report numbered 62885, dated 26 March 2012, stating that the 10.857 carat emerald is natural, Green colour of medium strong saturation, of Colombian origin, with no indications of clarity enhancement.