Colombian Emerald and diamond brooch-pendant, late 19th century. Estimate 20,000 — 30,000 GBP. Photo Sotheby's

The square step-cut emerald set within an open work scroll frame set with circular-cut, cushion-shaped and rose diamonds, brooch fitting and pendant loop detachable, hinged pendant bail. 

Property of a gentleman of title 

Accompanied by the Gem & Pearl Laboratory report no. 10717, stating that the emerald was found to be Colombian, with evidence of moderate clarity enhancement. 

Sotheby's. Fine Jewels London, 18 Mar 2015, 10:30 AM