A blockbuster rock boasting rare symmetry and polish will go under auction in New York. The 3.15 carat circular-cut colored diamond is the largest ever to be offered at auction.

It’s also the largest reddish orange diamond ever graded at the Gemmological Institute of America. The stone ‘to die for’ has been estimated at $700,000-$1,200,000.

The diamond’s rarity is a fusion of both, its intense color and large size. Highly saturated diamonds in shades of red and orange are considered to be among the rarest of all fancy colored diamonds. Although the cause of their coloration is a natural phenomenon that is not thoroughly clear, it’s believed to occur when minute quantities of nitrogen or hydrogen are present when the diamond’s crystal lattice is forming deep within the earth’s crust.

The Elizabeth Taylor diamond owned by US actress Elizabeth Taylor, a gift from Richard Burton, on display during a preview of The Collection of Elizabeth Taylor.(AFP Photo / Stan Honda)

1According to experts at the Christie’s auction house very few red diamonds larger than one carat are known to exist.
Among the worlds largest is a circular-cut 5.03 dark red diamond on display at the Smithsonian Institution in Washington, D.C. 

“Since the start of 2012, this has proven to be a vibrant year of strong prices for top-quality diamonds, colored gemstones, natural pearls, and signed jewels at auction,” head of Jewelry for Christie’s Americas and Switzerland, Rahul Kadakia, noted.

A model holds the "Archduke Joseph" historial diamond.(AFP Photo / Fabrice Coffrini)

Per-carat prices for exceptional diamonds have continued to climb this auction season, boosted by collector demand for investment-quality gems. The historic 76.02 carat, D-color Archduke Joseph Diamond fetched US$21.5 million at Christie’s recent jewelry auction in Geneva, setting a new world auction record for a colorless diamond. It also set a new record per-carat price for a colorless diamond, at $282,545 per carat, surpassing the landmark $266,000 per carat price achieved for the 33.19 carat, D-color Elizabeth Taylor Diamond, sold at Christie’s in December last year.

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