A superb ruby and diamond ring

Set with a cushion-cut ruby, weighing approximately 6.76 carats, flanked on either side by a cushion-cut diamond, weighing approximately 2.01 and 2.02 carats, mounted in platinum. Est. $500,000 - $700,000 - Sold $866,500

With report CS 38123 dated 19 December 2005 from the American Gemological Laboratories stating that it is the opinion of the Laboratory that the origin of this material would be classified as Classic Mogok, Burma (Myanmar). Heat enhancement: None. Clarity enhancement: None

Accompanied by a supplemental letter stating that the American Gemological Laboratories has completed a thorough analysis of the 6.76 carat Burma ruby documented in AGL Report No. CS 38123. This examination includes a comparative study of the various quality parameters that define a gemstone. A summary quality assessment statement designated a Total Quality Integration Rating, classifies this stone as Exceptional. This rating category is reserved for a limited number of exceedingly rare gemstones that exhibit all the individual elements that define the highest level of a category.

With report no. 13694117 dated 21 October 2004 from the Gemological Institute of America stating that the diamond, weighing approximately 2.01 carats, is D color, VS1 clarity

With report no. 14144436 dated 14 January 2005 from the Gemological Institute of America stating that the diamond, weighing approximately 2.02 carats, is E color, VS2 clarity

Note: Of all the countries in Asia, it is perhaps Burma, currently known as Myanmar, that has the most valuable gem deposits. So unique are the quality elements exhibited by the rubies found here that it has emerged as the standard by which other stones are judged.

Rubies from Burma are therefore the most treasured in the world. Those over 5 carats, and in particular, ones that have not undergone any thermal enhancement are exceedingly rare. This is mainly because the famous mines of Mogok are yielding fewer and fewer stones of an important size. It is also because the market has seen a diminishing number of antique ruby jewelry and old Burmese gems appearing for sale.

The 6.76 carat Burmese ruby offered for sale exhibits all the individual elements that define the highest level of an ideal gem. It displays a pigeon-blood red color typical of old Burmese material and a high degree of transparency. This creates a mesmerizing luminous effect, which makes the stone "come alive," and is observed in only the finest rubies. The highly-regarded Gübelin Gem Laboratory also confirms that this exceptional ruby has been spared of any form of enhancement and along with its impressive size, is a remarkable natural wonder.

Christie's. Jewels: The New York Sale. 22 April 2009. New York, Rockefeller Plaza www.christies.com Photo: Christie's Images Ltd 2009