Important emerald and diamond ring. Photo Sotheby's

Featuring a step-cut emerald weighing 30.32 carats, the shoulders each set with a step-cut diamond, size 511/2, sizing band. Estimation 270,000 — 450,000 CHF

Accompanied by SSEF report no. 72267, stating that the emerald is of Colombian origin, with a minor amount of oil in fissures, together with an appendix letter expressing the exceptional quality of this emerald.

"Microscopic examination revealed inclusions, which represent the hallmarks of Colombian emeralds from the famous mining areas such as Muzo, Coscuez, and Chivor, all located in the green foothills of the Cordillera Oriental in the Colombian Andes. Its vivid green colour is due to a combination of well-balanced trace elements in the gemstones, typical and characteristic for the finest emeralds from Colombia," SSEF appendix letter, 16 January 2014.

Sotheby's. Magnificent Jewels and Noble Jewels. Genève, 13 mai 2014 - http://www.sothebys.com/