A fine 14.95 carats Colombian emerald and diamond brooch.  Estimate CHF240,000 – CHF330,000 ($241,752 - $332,409). Photo Christie's Image Ltd 2015

The circular panel centering a cushion mixed-cut emerald, weighing approximately 14.95 carats, set within a rose and old-cut diamond openwork surround, suspending three rose, old-cut drops, the oval old-cut diamond surmount to the graduated rose-cut diamond pendant loop, with detachable pendant fitting, 10.0 cm, with French import marks for silver and gold

Accompanied by report no. CS67048 dated 26 March 2015 from the AGL American Gemological Laboratories stating that the origin of the emerald is Colombia, with indications of minor traditional clarity enhancement. 

Christie's. GENEVA MAGNIFICENT JEWELS, 10 November 2015, Geneva