Lot 1704. A Magnificent Unmounted 80.88 carats Type IIa Diamond. Estimate 78,000,000 — 100,000,000 HKD (9,952,020 - 12,759,000 USD). Courtesy Sotheby's.

The emerald-cut diamond weighing 80.88 carats.

Accompanied by GIA report no. 2191753592, dated 6 June 2019, stating that the diamond is D Colour, Flawless, Excellent Polish and Symmetry; further accompanied by a diamond type classification report stating that the diamond is determined to be a Type IIa diamond. Type IIa diamonds are the most chemically pure type of diamond and often have exceptional optical transparency. 

Sotheby's. Magnificent Jewels and Jadeite, Hong Kong, 07 Oct 2019