Lot 267. 15.83 carats, F color, SI2 clarity Diamond ring. Estimate 250,000 - 300,000 USD. Lot sold 300,000 USD. Photo: Sotheby's 2007

The cushion-shaped diamond weighing 15.83 carats framed by small round diamonds, the shoulders also accented with round diamonds, mounted in platinum, size 6.   

Accompanied by GIA report no. 14879555 stating that the diamond is F color, SI2 clarity. 

Sotheby's. Magnificent Jewels. New York, 24 Apr 2007