Diamonds from an ancient dwarf planet in our solar system may have formed after it was hit by an asteroid, according to scientists.
There is a rare form of diamond in meteorites from the mantle of a dwarf planet.
Dame Kathleen Lonsdale was the first woman to be elected as a Fellow of the Royal Society and she was a pioneer in the field of crystallography.
The team, made up of scientists from several universities, found evidence of lonsdaleite in meteorites and published their findings in the PNAS. The leader of the study was a professor at the university.
The team predicted that the hexagonal structure of lonsdaleite's atoms would make it harder than regular diamonds.
The director of the RMIT Microscopy and Microanalysis Facility said that the study proved that lonsdaleite exists in nature.
The largest lonsdaleite crystals have been found that are much thinner than a human hair.
New manufacturing techniques for ultra-hard materials could be helped by the unusual structure of lonsdaleite.
The origin of these diamonds is a mystery.
The meteorites were captured with advanced electron microscopy techniques to create snapshots of how diamonds formed.
"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," he said.
Growing diamonds in a specialized chamber is one of the ways that chemical vapor deposition can be used.
The team proposed that the meteorites formed from a supercritical fluid at high temperature and moderate pressures.
Tomkins said that diamond was replaced by lonsdaleite as the environment cooled.
Nature has given us a way to try and replicate in industry. If we can develop an industrial process that promotes replacement of pre-shaped graphite parts by lonsdaleite, we think that it would be possible to make tiny, ultra-hard machine parts.
The study findings helped address a long-standing mystery about the formation of the carbon phases in ureilites.
The paper "Sequential Lonsdaleite to Diamond Formation in Ureilite meteorites via In Situ Chemical fluid/Vapor Deposition" was published in the PNAS.
More information: Sequential Lonsdaleite to Diamond Formation in Ureilite Meteorites via Chemical Fluid/Vapor Deposition, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2208814119 Journal information: Proceedings of the National Academy of Sciences
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