Strange diamonds from an ancient dwarf planet in our solar system could lead to the production of ultra-hard machine parts, scientists say.
Monash University researchers, in collaboration with CSIRO, RMIT University, the Australian Synchrotron and the University of Plymouth, have confirmed the existence of lonsdaleite, a rare, hexagonal-shaped diamond believed to be much more strong and tough than its more typical cubic cousin. ureilite meteorites from the mantle of a dwarf planet.
The study provides evidence of lonsdaleite forming in nature, offering clues to synthetic production that could make more durable machine parts, which CSIRO scientist Colin MacRae says could have huge implications for industries such as mining.
“If something that’s harder than diamond can be easily manufactured, that’s something the industry would like to know,” MacRae said.
Photo: Cross-section of ureilite showing lonsdaleite, captured with the CSIRO Electron Microanalyzer (EPMA). Iron in red, magnesium in green, silicon in blue, lonsdaleite in yellow and diamond in pink.
Manufacture of tiny and ultra-hard machine parts
The study’s lead author, Professor Andy Tomkins, said the current method of producing industrial diamonds involves chemical vapor deposition, in which diamonds are formed on a substrate from a mixture of gases at low pressures
“We propose that the lonsdaleite in the meteorites formed from a supercritical fluid at high temperature and moderate pressures, almost perfectly preserving the textures of pre-existing graphite,” he said.
“Later, lonsdaleite was partially replaced by diamond as the atmosphere cooled and the pressure decreased. So nature has provided us with a process to try to replicate in industry.
“We think that lonsdaleite could be used to make tiny, ultra-hard machine parts if we can develop an industrial process that promotes the replacement of preformed graphite parts with lonsdaleite.”
SUBSCRIBE
Get the latest Stockhead news delivered to your inbox for free.
“*” Indicates mandatory fields
It’s free. Unsubscribe whenever you want.