AN EXTRAORDINARY COLOURED DIAMOND RING
Lot 393 ANOTHER PROPERTY

AN EXTRAORDINARY COLOURED DIAMOND RING

Closed14 May 2008

Price Realised

CHF 9,233,000

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AN EXTRAORDINARY COLOURED DIAMOND RING
Set with a rectangular-cut fancy intense blue diamond weighing 13.39 carats, to the micro pavé-set fancy pink diamond surround and diamond bifurcated hoop, mounted in platinum and 18k white gold, ring size 6
Accompanied by report no. 8766622 dated 20 June 2007 from the GIA Gemological Institute of America stating that the diamond is Fancy Intense Blue colour, VS1 clarity

With a note stating that 'the diamond has been determined to be a type IIb diamond. Type IIb diamonds are very rare in nature (from our experience, less than one half of one percent) and contain small amounts of boron that can give rise to a blue or gray coloration. An unusual property of type IIb diamonds is that they are semi-conductors and conduct electricity. Historically, the ancient mines of India produced occasional blue diamonds but today the most significant source is limited to the Cullinan (formerly Premier) Mine in South Africa.'

Specialist note

Not only are the size and colour of this superb stone outstanding, but furthermore the combined qualities of even colour distribution, VS1 clarity, very good polish and symmetry and no fluorescence, highlight an exceptional pedigree.



'Blue diamonds of any size are unusual. Polished blue diamonds, particularly strongly colored examples such as the 13.39 carat emerald cut described on GIA report 8766622 are extremely rare for its color and its size. Throughout GIA's decades of grading and classifying fancy colored diamonds encountering a blue, of any quality weighing more than a few carats is unusual.
Arguably, the most famous diamond in the world is the 44.50 carat Fancy Deep Grayish Blue Hope diamond housed in the Smithsonian Institute in Washington D.C.

In addition to their unique gem qualities, blue diamonds such as the 13.39 carat emerald cut, possess physical properties that have been carefully studied by scientist for decades. Their ability to conduct heat and act as semi-conductors for electricity is well known amongst scientist and have been reproduced in the laboratory for scientific applications.

Strongly colored blue diamonds are one of the most sought after gems in which the supply has been far outstripped by the demand. Unlike most other colored diamonds, even rare colors such as pink, there have been several locations where they have been recovered. Blue diamonds have historically come from very few sources. Primarily they have come from the legendary Premier mine in South Africa (the name was recently changed to Cullinan) and sporadically from a few other locations.

Strongly colored blue diamonds are among the rarest of all gems examined in the Laboratory. Their occurrence in any size or depth of color is an unusual occurrence and quite notable when they are over five carats in size.'


Letter from the GIA Laboratory, 06 March 2008