This 228.31-carat, pear-shaped diamond—called “The Rock”—is about the size of a golf ball and is one of the rarest gems to be sold at an auction.

In auction houses like Christie’s, majestic gemstones and impressive pieces often make an appearance—each one fetching high selling prices, sometimes over and beyond what is expected. But in some cases, the selling price of an item falls short from its estimated value. An example of the latter includes the largest diamond to ever come up for auction: “The Rock.”

A 228.31-carat, pear-shaped colorless diamond, “The Rock” originated from South Africa—home to some of the largest diamonds in the world, which include the pear-shaped “Star of Africa” and rose cushion cut “Golden Jubilee.” This impressive stone, however, is about the size of a golf ball and was previously worn as a lavish Cartier necklace by its former owner.

Along with the pear-shaped stone, the new owner will receive a round diamond and platinum pendant mounting from the French luxury brand.

Photo by Denis Balibouse, Reuters

Falling Below Expectations

“Often with these largest stones, they sacrifice some of the shape in order to keep the weight,” Max Fawcett, the head of Christie’s jewelry department in Geneva, told Reuters. “[But] this is a perfectly symmetrical pear-shape form and… one of the rarest gems ever to be sold at auction.”

Despite the grandeur and rarity of “The Rock,” its hammer price fell short during the quick bidding period last Wednesday, May 11. Instead of reaching or going over the auction house’s 30,000,000 CHF ($30.2 million) high estimate, the diamond was sold for 21,681,000 CHF ($21.9 million) at Christie’s in Geneva.

To date, the record for a colorless diamond sale belongs to an intricate emerald and diamond necklace from Swiss luxury jeweler de Grisogono, which featured a 163.41-carat emerald-cut diamond pendant—the largest flawless D-colored diamond ever to come to auction. It sold for 33,500,000 CHF ($33.8 million USD) last 2017.

Photo by Denis Balibouse, Reuters

A Smashing Success

However, other lots in the “Magnificent Jewels” sale went over and beyond their expected prices. These include a 1940s pink sapphire, ruby, and diamond brooch that was mounted by Cartier. It sold for 579,600 CHF ($585,000)—over 11 times its high estimate! On the other hand, a 19th-century diamond and pearl tiara sold for more than triple its high estimate at 2,394,000 CHF ($2.4 million).

The final lot in this auction included a diamond that was nearly as large as “The Rock”—a historically important 205.07-carat, yellow cushion-shaped stone named “The Red Cross Diamond.” which sold for 14,181,250 CHF ($14.3 million). Moreover, a portion from this sale will be donated to the Geneva-based International Committee of the Red Cross (ICRC).

“The Red Cross Diamond” was first sold at Christie’s over a century ago to help the British Red Cross during World War 1, hence its name. According to Fawcett, this diamond was expected to sell for between $7 million and $10 million.

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