The stone, called lonsdaleite, has a hardness and strength that exceeds those of ordinary diamonds. The rare mineral arrived here via a meteorite, according to new research.
The revelation began to emerge when geologist Andy Tomkins, a professor at Monash University in Australia, was outside the field of meteorite classification. Study co-author Alan Salk, a doctoral student and researcher at RMIT University in Australia, said he had found a strange type of “curved” diamond in a space rock in northwest Africa.
Salk said Tomkins theorized that the meteorite carrying Lonsdalite came from the mantle of a dwarf planet that existed regarding 4.5 billion years ago.
“The dwarf planet was then subjected to a catastrophic shock by an asteroid, which released the pressure and led to the formation of these really strange diamonds,” he added.
With cutting-edge methods and future possibilities, the discovery is exciting, said Paul Asimov, professor of geology and geochemistry at Caltech. Azimov was not involved in the study.
“It’s really taking advantage of a number of recent developments in microscopy to do what they did as they did,” Asimov said.
The team was able to analyze the meteorite with the help of electron microscopy and advanced synchrotron techniques, which made maps of the space body’s components, including lonsdaleite, diamond and graphite, according to the study.
Diamond and lonsdaleite can be formed in three ways. It can be through high pressure and temperature over a long period of time, that is what diamonds look like on the Earth’s surface; meteor impact shock at high speed; Or releasing vapors of fractured graphite that would attach to a small piece of diamond and build on it, Asimov said.
He added that the way the mineral is formed can affect its size. The researchers in this study suggested that the third method constituted the largest sample they found.
“Nature has provided us with a process to try to replicate in the industry,” Tomkins said in a press release. “We believe that lonsdaleite can be used to make extra-rigid machine parts if we can develop an industrial process that promotes the replacement of preformed graphite parts with lonsdaleite.”
What is it exactly?
Asimov said long before this discovery, scientists debated the existence of Lonsdalite.
He added, “It seems to be a strange claim that we have a name for something, and we all agree on what it is,” and yet there are claims in society that it is not real metal, not real crystal, that you can have a macroscopic scale.”
Scientists first identified bits of the mineral in 1967, but they were minute — regarding 1 to 2 nanometers, which is 1,000 times smaller than what was found in the latest discovery, Salk said.
Asimow said finding a larger sample showed that lonsdaleite is not just an anomaly of other diamonds.
Salk said that regular diamonds, like the diamonds you see in fine jewelry, are made of carbon and have a cubic atomic structure. As the hardest material known to date, it is also used in manufacturing.
He added that Lonsdalite is also made of carbon, but has an unusual hexagonal structure instead.
Salk said researchers have modeled the lonsdaleite structure before, and they theorized that the hexagonal structure might make it 58% harder than regular diamond. This hardness might make rare space diamonds a valuable resource for industrial applications if scientists can find a way to use the new production method to produce large enough minerals.
What does that mean for us?
Now that scientists know regarding this mineral, the discovery raises the question of whether they can replicate it.
Salk said tools like saw blades, drilling bits and mining sites need to be permanently hard and wear-resistant, so a ready supply of lonsdaleite can make them work better. And now with a reliable scientific theory on how these large deposits formed, there’s a rough blueprint for making lonsdaleite in the lab.
From this discovery, we can also learn more regarding the interactions of the universe, said Phil Sutton, senior lecturer in astrophysics at the University of Lincoln in the UK. Sutton was not involved in the research.
Uncovering the story of where we came from and how we evolved, he added, it’s important to know that materials were exchanged between environments — even across solar systems.
Scientists named Lonsdaleite following crystallographer Dame Kathleen Lonsdale, who in 1945 became one of the first women elected as Fellows of the Royal Society of London.
