A 5.02-carat internally flawless fancy deep blue diamond is set to headline Christie’s Magnificent Jewels sale at The Henderson in Hong Kong later this month. The marquise brilliant-cut stone is flanked by trilliant-cut white diamonds in a platinum setting and carries a pre-sale estimate of $7 million to $10.3 million.

Christie's writes, "Infused with trace amounts of boron that give rise to its captivating, deep blue hue, this diamond embodies nature’s most mesmerizing wonders."

According to the Museum of Natural History, “less than one boron atom per million carbon atoms is sufficient to produce the blue coloration.”

Blue diamonds consistently fetch the highest prices at auction.

In April 2022, the 15.10-carat “De Beers Blue” nearly set a world record for the priciest vivid blue diamond ever sold at auction. The hammer price of $57.47 million ($3.8 million per carat) at Sotheby’s Hong Kong was just short of the $57.54 million ($3.9 million per carat) achieved by the 14.62-carat “Oppenheimer Blue” at Christie’s Geneva in 2016.

Back in 2015, “The Blue Moon of Josephine,” a 12.03-carat internally flawless fancy vivid blue diamond, sold for $48.5 million ($4 million per carat) at Sotheby’s Geneva.

Scientists believe that blue diamonds form about 400 miles below the surface, four times deeper than about 99 percent of all other diamonds.

Other notable lots at Christie's Hong Kong auction include the following:

-- "Oriental Sunrise." The property of a private collector, this lot includes a pair of earrings featuring matching fancy vivid orange-yellow diamonds accented by shield and tapered baguette-cut white diamonds in a platinum setting. The fancy-colored diamonds, which weigh 12.20 carats and 11.96 carats respectively, are described as having an oval mixed cut. The larger diamond has a clarity grade of VVS2, while the smaller one is rated VS1. The earrings carry a pre-sale estimate of $6.4 million to $10.3 million.

-- Magnificent Ruby and Diamond Necklace. Twenty-six oval-shaped rubies ranging in weight from 1.27 carats to 5.38 carats glimmer in this head-turning platinum and gold neckpiece. The rubies are complemented by pear- and marquise-shaped diamonds in a floral motif. The diamonds range from 1.00 carat to 1.21 carats in weight and D to F in color. Christie's is estimating that this piece will sell in the range of $5.2 million to $7.7 million.

-- Spectacular Emerald and Diamond Bangle. An octagonal step-cut emerald weighing 38.51 carats is accented by marquise and round diamonds in this bangle designed by Etcetera. The emerald is of Colombian origin and displays no indication of clarity enhancement. The total weight of the diamonds is 7.37 carats. This piece carries a pre-sale estimate of $2.3 million to $3.6 million.

-- Superb Ruby and Diamond Ring. Designed by Boghossian, this ring spotlights a cushion-shaped ruby weighing 6.24 carats. Sourced in Burma (now Myanmar), the ruby boasts a "pigeon blood red" color and a pre-sale estimate of $2.1 million to $3.2 million.

In total, Christie's will be offering 124 lots at The Henderson in Hong Kong on October 29.

Credits: Images courtesy of Christie's.