Lot 1891. An Important 18.45 carats Type IIa Diamond Ring. Estimate: 9,800,000-14,000,000 HKD. Lot sold 18,120,000 HKD (2,311,387 USD). Courtesy Sotheby's.

Set with a step-cut diamond weighing 18.45 carats, between two shield-shaped diamonds, mounted in platinum, size 7. 

Accompanied by GIA report no. 11506055, dated 21 August 2018, stating that the diamond is D Colour, VVS2 Clarity; together with an additional GIA worksheet stating that the diamond may be Potentially Flawless after repolishing; further accompanied by diamond type classification report stating that the diamond is determined to be Type IIa. Type IIa diamonds are the most chemically pure type of diamond and often have exceptional optical transparency. Also accompanied by an original GIA report, dated 3 April 2001.