Meet the mysterious diamond from outer space

Scientists have debated its existence. Tiny tracks provided clues. Now researchers have confirmed the existence of a celestial diamond after finding it on Earth’s surface.

The stone, called Lonsdaleit, has a hardness and strength that exceeds that of a normal diamond. The rare mineral got here via a meteorite, new research suggests.

The natural chemical process by which scientists believe Lonsdaleit is formed could inspire a way to manufacture extremely durable industrial components, according to the authors of the study, published Sept. 12 in the journal Proceedings of the National Academy of Sciences.

The revelation began to unfold when geologist Andy Tomkins, a professor at Monash University in Australia, was outside categorizing meteorites. He came across a strange “curved” diamond in a space rock in northwest Africa, said study co-author Alan Salek, a PhD student and researcher at RMIT University in Australia.

Tomkins theorized that the meteorite containing the Lonsdaleit came from the mantle of a dwarf planet that existed about 4.5 billion years ago, Salek said.

“The dwarf planet was then catastrophically hit by an asteroid, releasing pressure and creating these really weird diamonds,” he added.

The discovery is exciting with its cutting-edge methods and future possibilities, said Paul Asimov, professor of geology and geochemistry at the California Institute of Technology. Azimow was not involved in the study.

“It really takes advantage of a number of recent developments in microscopy to do what they did as well as they did,” Asimov said.

The team was able to analyze the meteorite using electron microscopy and advanced synchrotron techniques, which the study said produced maps of the space object’s components, including lonsdaleite, diamond and graphite.

Diamonds and Lonsdaleit can form in three ways. It can be formed by high pressure and high temperature over a long period of time, causing diamonds to form on the earth’s surface; the shock of a hyperspeed collision of a meteor; or the release of fumes from fractured graphite that would attach to and build up on a small diamond fragment, Asimov said.

The method that creates the mineral can affect its size, he added. The researchers suggested in this study that the third method formed the larger sample they found.

“Nature has thus provided us with a process that we can try and replicate in industry,” Tomkins said in a press release. “We believe that if we can develop an industrial process that encourages the replacement of pre-formed graphite parts with Lonsdaleit, Lonsdaleit could be used to manufacture tiny, ultra-hard machine parts.”

WHAT IS IT EXACTLY?

Long before this discovery, scientists debated the existence of Lonsdaleit, Asimov said.

“It seems like an odd claim that we have a name for something, and we all agree what it is,” he added, “yet there are claims in the community that it’s not a real mineral, it’s not a real crystal that you could have a macroscopic scale.”

Scientists first identified parts of the mineral in 1967, but they were tiny — about 1 to 2 nanometers, which is 1,000 times smaller than what was found in the most recent discovery, Salek said.

Finding a larger sample has shown that Lonsdaleit is not just an anomaly from other diamonds, Asimov said.

Regular diamonds, like those seen in fine jewelry, are made of carbon and have a cubic atomic structure, Salek said. As the hardest material known to date, they are also used in production.

Lonsdaleit is also made of carbon but instead has an unusual hexagonal structure, he added.

Researchers have previously developed models for the structure of Lonsdaleit, and they theorized that the hexagonal structure could make it up to 58 percent harder than regular diamonds, Salek said. This hardness could make the rare space diamond a valuable resource for industrial applications if scientists find a way to make large enough minerals using the new production method.

WHAT DOES IT MEAN FOR US?

Now that scientists know about this mineral, the discovery raises the question of whether they can replicate it.

Tools like saw blades, drill bits and mining sites need to be permanently hard and wear-resistant, so an immediate supply of Lonsdaleit could improve their performance even further, Salek said. And now, with a credible scientific theory as to how these larger deposits formed, a rough plan exists to create Lonsdaleit in a lab.

We can also learn more about the interactions of the universe from this discovery, said Phil Sutton, lecturer in astrophysics at the University of Lincoln in the UK. Sutton was not involved in the research.

To uncover the history of where we came from and how we evolved, he added, it’s important to know that materials have been exchanged between environments — even between solar systems.

Scientists named Lonsdaleite after crystallographer Dame Kathleen Lonsdale, who was one of the first women elected to the Royal Society of London in 1945.