Lot 292. Fine 20.07 carats D Colour, Internally Flawless pear-shaped diamond ring. Estimate 1,180,000 — 2,165,000 CHF. Photo: Sotheby's.

Set with a pear-shaped diamond weighing 20.07 carats, between triangular diamond shoulders, size 511/2, central diamond detachable and may be worn as a pendant.

Accompanied by GIA report no. 14141695, stating that the diamond is D Colour, Internally Flawless. 

Sotheby's. Magnificent Jewels and Noble Jewels, Geneva, 16 Nov 2016, 10:30 AM