Strange hexagonal diamonds might have been jettisoned into space whenever a dwarf planet collided with a big asteroid around 4.5 billion years back.
New research identified the hexagonal diamonds, also known as lonsdaleite, in a rare class of meteorites that may result from the mantle of a dwarf planet. Like graphite, charcoal and diamond, lonsdaleite is really a particular structural type of carbon. Where diamond’s carbon atoms are arranged in a cubic shape, the carbon atoms in lonsdaleite are arranged in hexagons.
“This study proves categorically that lonsdaleite exists in nature,” Dougal McCulloch, a microscopist at RMIT University in Australia, said in a statement. “We’ve also discovered the biggest lonsdaleite crystals recognized to date which are up to micron in proportions much, much thinner when compared to a human hair.”
Lonsdaleite was initially discovered in the Canyon Diablo meteorite in 1967 and was named after British crystallographer Dame Kathleen Lonsdale. The brand new research predicts that the hexagonal form of lonsdaleite helps it be harder than regular diamonds with a cubic structure, which can pen new manufacturing ways to make ultra-hard materials.
The researchers studied lonsdaleite in ureilite meteorites, a rare class of space rocks that scientists think may contain material from the mantle of dwarf planets. The team analyzed slices of the meteorites beneath the microscope to recognize the lonsdaleite and predict its origins, and in addition studied regularly shaped diamonds within the rock.
“There’s strong evidence that there surely is a newly discovered formation process for the lonsdaleite and regular diamond, that is just like a supercritical chemical vapor deposition process which has occurred in these space rocks, probably in the dwarf planet soon after a catastrophic collision,” McCulloch said. “Chemical vapor deposition is among the techniques people make diamonds in the lab, essentially by growing them in a specialized chamber.”
The scientists believe lonsdaleite in the meteorites formed from the supercritical liquid at high temperatures and under increased pressures. This extreme environment allowed the lonsdaleite to wthhold the shape and texture of graphite. Eventually, because the environment cooled and the pressure reduced lonsdaleite was partially replaced by diamond.
The team thinks that industry could mimic the procedure to create the unusual mineral.
“Nature has thus provided us with an activity to replicate in industry,” Andy Tomkins, team leader and a geologist at Monash University in Australia, said in exactly the same statement. “We believe that lonsdaleite could possibly be used to create tiny, ultra-hard machine parts if we are able to develop an industrial process that promotes the replacement of pre-shaped graphite parts by lonsdaleite.”
The team’s research was published Monday (Sept. 12) in the Proceedings of the National Academy of Sciences.