When scientists used advanced imaging techniques to look at diamonds ejected from the meteorite that crashed into Canyon Diablo, they found that these were not ordinary diamonds. They report in their findings, published in the journal Proceedings of the National Academy of Sciences, that these stones share the famous hardness of diamonds, but are also unusually malleable. They also have tunable electronics, making them potentially useful for electronics applications.
Used as jewellery, diamonds are made up of carbon atoms with a cubic shape, where each atom is joined to four others, sometimes with other elements that change color. Lonsdaleit diamonds found in the meteorite in Diablo canyon contain a rare form of carbon thought to be composed of atoms in a hexagonal lattice, and with this feature these diamonds fall into the same category as graphite, amorphous carbon graphene and graphene.
Over the past two years, two teams have independently described methods of producing lonsdaleite in the lab. The available amounts of lonsdaleite found so far were too small to test some of its properties. However, modeling suggests that the hexagonal formation should be 58 percent harder than ordinary diamonds.
Co-author of the paper, Professor Christoph Salzmann of University College London, sees potential applications in the production of such crystals. “Through the controlled layer growth of structures, it should be possible to design materials that are both ultra-hard and ductile. These have electronic properties that can be tuned from a conductor to an insulator,” he says. “They can be exploited in a variety of applications, from abrasives and electronics to nanomedicine and laser technology.”
This meteorite, which fell into Diablo canyon about 50,000 years ago, gave rise to Meteor Crater, one of Earth’s most intact impact craters.
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