Ragan's Jewelry Blog
August 14th, 2014
Fancy red diamonds are so rare that over the 30-year history of the iconic Argyle Pink Diamonds Tender only 13 have come to market. The 2014 edition of the tender will feature a record four such diamonds, including the spectacular Argyle Cardinal™, a 1.21-carat radiant-cut fancy red.

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STARS OF THE SHOW: Four fancy red diamonds, including the 1.21-carat Argyle Cardinal (second from left). Photo supplied by Rio Tinto.

Rio Tinto, which owns the Argyle Mine in Western Australia, recently showcased the four red diamonds — along with 51 top-quality pink and purplish-red diamonds — to a select group of 150 customers and the press. The annual tender represents the pinnacle of the mining company’s production.

The Sydney event marked the beginning of a two-month promotional tour that will offer tender viewings in New York, Hong Kong and Perth. Bidding on the stones will close on October 8.

Red and pink diamonds demand a high price — typically 50 times greater than similar white diamonds, according to Rio Tinto. The four red diamonds in the tender are expected to fetch from $1 million to $2 million per carat. Just last year, the 1.56-carat Argyle Phoenix™ sold for more than $2 million to a Singapore-based jeweler.

“Decades ago, no one would have believed that Australia held the secret of diamonds, let alone virtually the world’s entire source of rare pink and red diamonds,” said Rio Tinto’s managing director Jean-Marc Lieberherr. The company boasts that Argyle produces more than 90 percent of the world’s pink diamonds.

It is believed that red diamonds get their rich color from a molecular structure distortion that occurs as the jewel forms in the earth’s crust. By contrast, other colored diamonds get their color from trace elements, such as boron (yielding a blue diamond) or nitrogen (yielding yellow), in their chemical composition.