Lot 2073. The Jonker V. An exclusive 25.27 carats Type IIa diamond ring, by Harry Winston. Estimate HKD 17,500,000 - HKD 28,000,000 (US$2,200,000-3,500,000). Price realised HKD 40,860,000. © Christie's Images Ltd 2017

Set with a rectangular-cut diamond, weighing approximately 25.27 carats, mounted in gold, ring size 4 with ring sizer, in blue leather Harry Winston case. With maker's mark for Harry Winston, no. 74149

Accompanied by report no. 11924246 dated 1 February 2017 from the GIA Gemological Institute of America stating that the diamond is D colour, VVS2 clarity; and a Diamond Type Classification letter stating that the diamond has been determined to be Type IIa  

Note: The Jonker V. 

Found on January 17th, 1934, the extraordinary 726 carats Jonker rough was discovered and named after Jacob Jonker. At the time, the Jonker was the fourth largest gem quality diamond ever unearthed. The stone was subsequently purchased by Joseph Bastiaenen of the Diamond Corporation Ltd., a company owned by Sir Ernest Oppenheimer. In 1935, it was purchased by Harry Winston and was displayed during the Silver Jubilee Celebrations of the Coronation of King George V and Queen Mary.

Lazare Kaplan was chosen to cut the important diamond. He studied the Jonker for months and after painstaking calculating and examining the piece, the stone was ultimately cleaved and sawed into 13 pieces. The largest diamond weighed 142.90 carats and retained the name of Jonker. It was later recut to 125.35 carats and is one of the most perfectly-cut diamonds in the world. Jonker Diamond V, a rectangular- cut diamond, originally weighed 25.78 carats and was subsequently recut to 25.27 carats to produce an extraordinary diamond. Although larger stones have since been owned and cut by Harry Winston, the Jonker Diamonds are greatly esteemed and sought after by important diamond collectors throughout the world.

Reference: Thompson, R. (2016 November 21). The World of Famous Diamonds. Retrieved from http://famousdiamonds.tripod.com/

Christie's. Hong Kong Magnificent Jewels, 30 May 2017, Convention Hall