Pink diamonds, as well as the world’s largest diamond mine, may have formed during the breakup of a supercontinent known as Nuna, claims a newly published article in the scientific journal Nature Communications.
The article, titled “Emplacement of the Argyle diamond deposit into an ancient rift zone triggered by supercontinent breakup,” was published on September 19.
The article’s lead author is Dr. Hugo Olierook, a research fellow at Curtain University in Perth, Western Australia.
The now-closed Argyle Diamond Mine, located in northern Western Australia, is the subject of the piece.
Pink diamonds were first discovered at the site in 1983, says the website for Argyle Pink Diamonds. The mine was the largest source of natural diamonds.
It closed in 2020.
Olierook said that with the help of “laser beams smaller than the width of a human hair,” his team was able to date the Argyle Diamond Mine at 1.3 billion years old.
“Which is 100 million years older than previously thought,” he said in a news release on Tuesday.
“Meaning it would likely have formed as a result of an ancient supercontinent breaking apart.”
The mine is “located at the point where the Kimberley region and the rest of northern Australia smashed together many years prior,” he said in the release.
That collision caused a “scar” in the earth, he said.
“While the continent that would become Australia didn’t break up, the area where Argyle is situated was stretched, including along the scar, which created gaps in the earth’s crust for magma to shoot up through to the surface, bringing with it pink diamonds,” he also said in the release.
The combination of deep carbon, plus the continents colliding and then stretching, resulted in a plethora of diamonds, he said.
It is possible that other large diamond deposits exist around the world, including in Australia, said Olierook.
It’s possible “similar pink diamond-bearing volcanoes still sit undiscovered.”
“Most diamond deposits have been found in the middle of ancient continents because their host volcanoes tend to be exposed at the surface for explorers to find,” he said in the release.
“Argyle is at the suture of two of these ancient continents, and these edges are often covered by sand and soil, leaving the possibility that similar pink diamond-bearing volcanoes still sit undiscovered, including in Australia.”
Pink, and other unusually colored diamonds, remain highly coveted and sought-after gems.
“Argyle Diamond Mine accounted for more than 90% of the world’s supply of pink diamonds,” says its website, which claims that there is “no other source in the world known to consistently produce diamonds of Argyle’s iconic spectrum.”
Even though the Argyle Diamond Mine produced more pink diamonds than anywhere else, the diamonds were still astoundingly rare, said the website.
“Of approximately 15 million carats of rough diamonds that were produced from the Argyle Diamond Mine each year, less than 1% was pink,” said the Argyle Pink Diamonds website.
Science News, in a piece about the new findings, noted that questions remain about the Argyle formation and its pink diamonds.
“To make a diamond blush, something more powerful than mere mantle conditions must contort its sturdy crystal structure, altering how it absorbs and transmits light,” the publication said.
It also noted, “The oddities of the Argyle formation have long puzzled geologists.”
It said the diamond mine there stopped production in late 2020 after “exhausting the diamonds that were economically feasible to extract.”