Diamonds created by an interstellar collision of a dwarf planet and an asteroid could lead to the development of new super-hard materials for tools and production, researchers say.
Rare lonsdaleite diamonds have been found in ureilite meteorites and likely come from the interior of a dwarf planet, a team of researchers report this week in the Proceedings of the National Academy of Sciences.
The presence of lonsdaleite, a substance potentially stronger than traditional diamonds, could eventually lead to production of more durable industrial machine parts for mining and other industries, said Colin MacRae, a scientist with Commonwealth Scientific and Industrial Research Organization (CSIRO) in Canberra, Australia .
Where diamond’s carbon atoms are arranged in a cubic shape, the carbon atoms in lonsdaleite are arranged in hexagons.
“If something that’s harder than diamond can be manufactured readily, that’s something (industries) would want to know about,” he said in a description of the research on the CSIRO website.
The substance behind space diamonds
Lonsdaleite gets its name from British scientist Dame Kathleen Lonsdale, who advanced the study of crystallography and in 1945 was the first woman elected to the Royal Society of London. Its existence has been controversial, but the Australian and UK research team used high resolution analysis to find graphite, diamond and lonsdaleite in the meteorite samples.
“This study proves categorically that lonsdaleite exists in nature,” said Dougal McCulloch, director of the RMIT University Microscopy and Microanalysis facility in Melbourne, Australia, in a summary on the RMIT University website.
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The researchers estimate that the substance formed about 4.5 billion years ago when an asteroid collided with a dwarf planet in our solar system. When the asteroid impacted the planet’s warm core, the conditions led to the creation of lonsdaleite and traditional diamonds from the existing carbon.
Since then, meteorites from the dwarf planet have fallen to Earth and collected over recent centuries. The study of the meteorite fragments suggests “there’s strong evidence that there’s a newly discovered formation process for the lonsdaleite and regular diamond, which is like a supercritical chemical vapor deposition process that has taken place in these space rocks, probably in the dwarf planet shortly after a catastrophic collision, ”McCulloch said.
How big are these diamonds we’re talking about?
This finding involves diamonds, but we’re not talking about something the size of the Hope Diamond.
The largest lonsdaleite crystals they have discovered are a micron in size, McCulloch said. “Much, much thinner than a human hair.”
Still, microscopic findings could lead to big developments in the future, since the process of chemical vapor deposition is already used to make diamonds in lab settings.
“Nature has thus provided us with a process to try and replicate in industry,” said Prof. Andy Tomkins, a geologist at Monash University in Clayton, Australia who lead the research team, in a statement.
“We think that lonsdaleite could be used to make tiny, ultra-hard machine parts if we can develop an industrial process that promotes replacement of pre-shaped graphite parts by lonsdaleite,” he said.
Follow Mike Snider on Twitter: @mikesnider.