Lot 1827. Highly important unmounted 25.50 carats D colour, Flawless clarity brilliant-cut Type IIa diamond. Estimate 30,000,000 — 38,000,000 HKD. Lot sold 39,860,000 HKD. Photo Sotheby's 2011

An unmounted brilliant-cut diamond weighing 25.50 carats.

Accompanied by GIA report numbered 5121745598, dated 10 February 2011, stating that the 25.50 carat diamond is D colour, Flawless clarity, with Excellent Cut, Polish and Symmetry; also accompanied by 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. Jewels and Jadeite, Hong Kong, 06 Apr 2011.