Lot 311. A rare 5.04 carats VS1  circular-cut fancy gray-blue diamond ring. Estimate $1,750,000 – $2,500,000. Price realised USD 2,285,000. Photo Christie's Image Ltd 2015

Set with a circular-cut fancy gray-blue diamond, weighing approximately 5.04 carats, mounted in 18k rose gold

With report 17476658 dated 23 October 2014 from the Gemological Institute of America stating that the diamond is fancy gray-blue, natural color, VS1 clarity

Notes: Natural blue diamonds belong to the rare Type IIb category of diamonds. They are semi-conductors of electricity—an attribute which distinguishesblue diamonds from all other types of diamonds. The blue color is caused by structural features in the diamond’s crystal lattice combined with minute quantities of the element Boron. One of the world’s most famous blue diamonds with a gray modifer is the Hope Diamond. The Hope Diamond, a Fancy Deep Grayish Blue diamond of 45.42 carats, was found in India’s fabled Golconda mines which stopped producing diamonds over 300 years ago. Almost all blue diamonds mined in recent years are from the Cullinan mine, previously known as the Premier diamond mine, in South Africa. This lot, a circularcut Fancy Gray-Blue diamond weighing approximately 5.04 carats, is rare not only for its color grade but also for its round brilliant-cut; most fancy colored diamonds are polished into fancy shapes to maximize their color emission.

Christie's. MAGNIFICENT JEWELS, 14 April 2015, New York, Rockefeller Plaza