A 1.56-carat fancy red diamond called the “Argyle Phoenix” stole the show last week at Phillips’ “Geneva Jewels Auction: Two.”

The famous diamond, which was originally revealed to the market in 2013 as part of Rio Tinto’s annual tender, brought in $4.2 million and cemented two auction records — the highest price AND the highest price-per-carat ever achieved for a fancy red diamond.

At the fall 2013 tender, the Argyle Phoenix was sold to a Singapore-based jeweler for more than $2 million. This past week, the gem re-entered the market as one of the top lots of Phillips’ auction and eventually yielded nearly three times the pre-auction high estimate of $1.5 million. British luxury jeweler Graff paid $2.7 million per carat for the ultra-rare gemstone, which jewelry trade journal jckonline.com reported is the largest known round brilliant fancy red diamond.

Argyle’s annual tender represented a small, but exclusive, collection of the rarest diamonds from a year’s worth of production at the Argyle mine in the remote east Kimberley region of Western Australia. Each year, only a few red diamonds would be offered for sale.

During its 37 years of production, the mine produced between 90% and 95% of the world’s pink and red diamonds. The depleted mine was officially shuttered on November 3, 2020, and the diamond industry has yet to find a reliable alternative source to fill the void.

Due to short supply and high demand, red and pink diamonds typically sell at prices 50 times greater than similar white 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.

The unexpected performance of the Argyle Phoenix overshadowed the auction’s highly touted headliner, a 6.21-carat Type IIa fancy vivid pink oval diamond that sold for $11.9 million, on the lower end of the pre-sale estimate of $10.5 million to $15 million. (The Type IIa classification represents a colorless diamond with no measurable impurities. Type IIa gems account for less than 2% of all natural diamonds.)

Credits: Photos courtesy of Phillips.