A COLORED DIAMOND RING
Set with a circular-cut fancy dark bluish gray diamond, weighing approximately 4.59 carats, within a two-row circular-cut diamond surround, to the circular-cut diamond gallery, bifurcated shoulders and half hoop, mounted in platinum
With report 10804377 dated 26 August 2013 from the Gemological Institute of America stating that the diamond is fancy dark bluish gray, natural color, VS1 clarity
Accompanied by a supplemental letter from the Gemological Institute of America 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. Among famous gem diamonds, the 70.21 carat Idol's Eye and the 45.52 carat Hope, are examples of type IIb.