This rare blue diamond is practically a miracle of nature

It’s also helping geologists better understand plate tectonics.

Unearthed in the largest mine in Botswana, the Okavango Blue Diamond is on display to the public for the first time. Courtesy of the Okavango Diamond Company

The industry term for naturally colored stones is “fancy,” which makes this rare, 20.46-carat Okavango Blue Diamond from Botswana a “fancy deep blue.” But even that might be an understatement for a gem that stands out from 99.98 percent of all other mined diamonds.

The unusually large diamond, which was revealed at a new exhibit at the American Museum of Natural History in New York City last week, is about the size of an almond in its shell. It was likely formed more than 415 miles underground, beneath a part of the inner Earth called the transition zone. The stone surfaced in May 2018 in Botswana’s Orapa mine, and was found by the Okavango Diamond Company.

But what’s most immediately striking about this gem is its hue: It gets its azure glow from boron that originated in seawater. Usually, diamonds contain a higher amount of nitrogen than boron, because nitrogen is more abundant in the environment and boron doesn’t typically exist deep in the Earth where the minerals form. But the Okavango Blue flips the script by containing a higher proportion of boron to nitrogen.

So how did element no. 5 get fused into this diamond? The ocean contains boron, which gets recycled into the bedrock and Earth’s mantle through a process called subduction. When a tectonic plate in the ocean naturally collides with a continental one and slides underneath it, boron gets driven deeper down into the transition zone. The traces get buried over time, and can eventually end up in a diamond.

“This is another piece of evidence to support our interpretation of how the planet works,” says George Harlow, a geologist and curator for the American Museum of Natural History’s Halls of Gems and Minerals.
Okavango Blue Diamond mounted in the American Museum of Natural History Halls of Gems and MineralsThe gem is currently on loan to the American Museum of Natural History from the government of Botswana. Photo: D. Finnin/©AMNH
Scientists have only learned about subduction in the past 50 years, Harlow says, so this theoretical idea behind the Okavango Blue’s formation further builds on our early understanding of a major planetary process. Still, the exact reason for the diamond’s chemical composition eludes mineralogists. “We don’t really understand why the nitrogen is so low,” says Harlow. Diamonds with higher amounts of nitrogen take on a yellowish color, so the near-flawless Okavango is a whopper of a find.

Until the industry comes up with a more apt term for such a stellar gem, “fancy” will have to do for the Okavango Blue.

Related Posts

Sergio Perez Now Faces a Significant New Obstacle in His Bid to Secure a Seat with Cadillac for the 2026 Formula 1 Season, Raising Doubts About His Future in the Sport as This Challenge Could Have Serious Implications for His Prospects in the Highly Competitive F1 World.

Sergio Perez would have been looking on at what’s happening at Red Bull Racing this week with great interest after losing his seat on the grid at…

Helmut Marko has issued an official statement regarding the future of Red Bull Racing, providing insights into the team’s plans following the shock removal of Christian Horner from his position. The decision has sent ripples throughout the Formula 1 world, and Marko’s comments aim to clarify Red Bull’s next moves.

Photo: © IMAGO Red Bull F1 advisor Helmut Marko has opened up on the team’s future following the shock dismissal of Christian Horner. Horner was removed from his…

The FIA’s Penalty Controversy That Cost Oscar Piastri a Well-Deserved Win: An In-Depth Look at the Decision That Shook the Racing World.

Lando Norris Triumphs at Silverstone, but Was Oscar Piastri’s 10-Second Penalty Fair? The 2025 British Grand Prix at Silverstone was a spectacle, with Lando Norris emerging victorious…

Christian Horner ‘Convinced’ Ferrari Move Depends on One Key Factor as Scuderia Targets Red Bull’s Ex-Chief.

Christian Horner might not have to wait long to receive offers to return to Formula 1 after Red Bull Racing sacked the Briton from his role as…

Ferrari Finally Opens Up About the Shocking and Unexpected Challenges Behind Their Struggles in Formula 1, Revealing the Complex Factors That Have Contributed to Their Ongoing Performance Issues, and What They Plan to Do to Overcome These Obstacles and Return to Their Former Glory in the F1 World.

Ferrari’s 2025 Formula 1 Season: The Road to Recovery The 2025 Formula 1 season has been a year of highs and lows for Scuderia Ferrari, with the…

The Surprising Impact of Christian Horner’s Red Bull Decision: Why George Russell May Lose the Most

The news that Red Bull Racing have parted ways with team principal Christian Horner took the Formula 1 world by surprise on Wednesday morning. Red Bull and Christian Horner are…