Scientists produce diamonds in minutes at room temperature

A study conducted by an international team of scientists from The Australian National University, RMIT University, the University of Sydney and the Oak Ridge National Laboratory and published in the journal Small reports that both Lonsdaleite and regular diamonds can form at normal room temperatures by just applying high pressures – equivalent to 640 African elephants on the tip of a ballet shoe.

“Natural diamonds are usually formed over billions of years, about 150 kilometres deep in the Earth where there are high pressures and temperatures above 1,000 degrees Celsius,” Jodie Bradby, professor at The Australian National University and one of the authors of the study, said in a media statement. “The twist in this story is how we apply the pressure. As well as very high pressures, we allow the carbon to also experience something called ‘shear’ – which is like a twisting or sliding force. We think this allows the carbon atoms to move into place and form Lonsdaleite and regular diamond.” The RMIT team’s pictures showed that the regular diamonds only form in the middle of these Lonsdaleite veins under this new method. (Image courtesy of the Royal Melbourne Institute of Technology). To observe and understand how this process works, the researchers used advanced electron microscopy techniques to capture solid and intact slices from the experimental samples to create snapshots of how the two types of diamonds formed. The pictures showed that the regular diamonds only form in the middle of Lonsdaleite veins under this new method. “Seeing these little ‘rivers’ of Lonsdaleite and regular diamond for the first time was just amazing and really helps us understand how they might form,” Dougal McCulloch, the study’s lead author and a professor at the Royal Melbourne Institute of Technology, said. According to the scientists, Lonsdaleite has the potential to be used for cutting through ultra-solid materials on mining sites. As such, they said that creating more of this rare diamond is the long-term aim of their work.