Lot 335A. Impressive unmounted 52.32 carats octagonal step-cut Colombian emerald. Estimate 1,440,000 — 2,400,000 CHF (1,316,039 - 2,193,398 EUR). Photo Sotheby's

The octagonal step-cut emerald weighing 52.32 carats, fitted case.

Accompanied by Gübelin report no. 15100133, stating that the emerald is of Colombian origin, with indications of insignificant clarity enhancement, and SSEF report no. 85456, stating that the emerald is of Colombian origin, with a minor amount of artificial resin in fissures. 

Sotheby's. Magnificent Jewels and Noble Jewels, Genève, 17 mai 2016, 10:00 AM