细节
AN IMPRESSIVE DIAMOND RING
Set with an old cushion-shaped diamond weighing 10.05 carats, mounted in platinum, ring size 5¾
Accompanied by report no. 5111484757 dated 23 December 2009 from the Gemological Institute of America stating that the 10.05 carat diamond is D colour, internally flawless clarity
Also accompanied by a supplemental letter from the Gemological Institute of America stating the 10.05 carat diamond has been determined to be a type IIa. Type IIa diamonds are the most chemically pure type of diamond and often have exceptional optical transparency. Type IIa diamonds were first identified as originating from India (particularly from the Golconda region) but have since been recovered in all major diamond-producing regions of the world. Among famous gem diamonds, the 530.20 carat Cullinan and the 105.60 carat Koh-i-noor, are examples of Type IIa
Report no. 1002014 dated 10 February 2010 from the Gübelin Gemmological Laboratory stating that the 10.05 carat diamond is D colour, VVS2 clarity
Also accompanied by a note from the Gübelin Gemmological Laboratory stating that diamonds are classified into two fundamental groups and this 10.05 carat diamond is classified as a type IIa which is chemically very pure and do not reveal infrared absorption characteristics related to nitrogen; additionally this 10.05 carat diamond possesses an antique cutting style which is rarely encountered in the gem trade today. It displays a colour and degree of transparency which are particular to the unique gemstones of Type IIa. Diamonds of this type, exhibiting an antique cutting style as well as a fine quality, are very rare and will most certainly evoke references to the historic term of 'Golconda'