A Christie's employee poses with the 14.62 carats Oppenheimer Blue diamond during a preview in Geneva, Switzerland on May 12, 2016. The largest "fancy vivid blue" diamond is estimated to sell for from US$ 38 to 45 million when auctioned during the Magnificent Jewels auction in Geneva on May 18. Denis Balibouse / Reuters, file

A Christie’s employee poses with the 14.62 carats Oppenheimer Blue diamond during a preview in Geneva, Switzerland on May 12, 2016. The largest “fancy vivid blue” diamond is estimated to sell for from US$ 38 to 45 million when auctioned during the Magnificent Jewels auction in Geneva on May 18. Denis Balibouse / Reuters, file

‘Oppenheimer Blue’ diamond

A 14.6-carat blue diamond auctioned at Christie’s in Geneva for $57.5 million, including fees, becoming the most expensive diamond ever auctioned.

The stone, called the “Oppenheimer Blue,” followed a record-high jewelry sale by Sotheby’s Tuesday, which totaled $175 million, the highest total ever for a jewelry sale.

The sales show that despite the volatile financial markets and slower art market, rare diamonds have retained their shine among the rich. The Sotheby’s sale included the $31.6 million sale of the “Unique Pink,” a 15.4-carat fancy vivid pink stone.

The “Oppenheimer Blue” — which went for a hammer price of $51.3 million — was among the most prized stones in the diamond world. Blue diamonds are arguably the rarest and most sought-after color. And the Oppenheimer was owned by Philip Oppenheimer, the late chairman of the De Beers diamond-marketing cartel.

Only 10 percent of all blue diamonds discovered are larger than a carat, making the Oppenheimer Blue a highly prized freak of nature. It also has the highest color rating of “vivid.”

The 12.03-carat “Blue Moon Diamond,” sold by Sotheby’s in November for $48.5 million, previously held the title of the priciest diamond sold at auction.

The largest diamond ever found was the 3,106-carat Cullinan diamond, unearthed in South Africa in 1905. It was cut into nine pieces that form part of the U.K. Crown Jewels.