Diamonds Never Seen Before Discovered in Canyon Diablo Meteorite from Space

The same minerals can be produced via quite diverse techniques. Although diamonds can be formed by a variety of terrestrial processes, they can also be formed by the shock wave created when an asteroid collides with the Earth and only a small fraction of its energy is wasted in the atmosphere.

When experts examined diamonds from the Canyon Diablo meteorite using modern imaging techniques, they discovered that these were not ordinary jewels. The Canyon Diablo meteorite landed roughly 50,000 years ago, forming Meteor Crater, one of the world's most preserved impact craters.

These stones have the renowned hardness of diamonds, according to a study from 2022, but they are also remarkably flexible. They can also be tweaked electrical characteristics, which make them potentially valuable for electronics.

The carbon atoms in the cubic form of the diamonds used in jewelry are connected to four other atoms on occasion by impurities of other elements, which can lend a tint of color. Prior to its discovery in the Canyon Diablo meteorite in 1967, the unusual type of carbon known as lonsdaleite was assumed to consist of atoms arranged in a hexagonal lattice. This was added to the list of carbon allotropes, which includes graphite, amorphous carbon graphene, and graphyne. Carbon is a very flexible element.

However, Dr. Péter Németh of the Institute for Geological and Geochemical Research and the study's co-authors discovered something even more intriguing when they used Raman spectroscopy and crystallography to examine lonsdaleite. It came out that lonsdaleite is composed of both conventional cubic diamonds and graphene-like domains that have co-grown in structures called diaphites. Additionally, the crystal has multiple instances of atom misalignment.

In recent years, two teams separately detailed how to make lonsdaleite in a laboratory setting. It seems that some individuals think that creating the hardest stone known to humans would be a pandemic activity; nevertheless, it appears that they may have been creating the hexagonal lonsdaleite they envisaged, not what is discovered in the Canyon Diablo and other meteorites.

Németh said in a statement that "we can get closer to understanding the pressure-temperature conditions that occur during asteroid impacts by recognizing the various intergrowth types between graphene and diamond structures."

Layer spacing unexpectedly changes when diamond and graphene come together, which explains prior spectroscopic discoveries of lonsdaleite. Lonsdaleite hasn't been found in sufficient amounts to evaluate some of its characteristics. The hexagonal structure should, however, be 58 percent tougher than typical diamonds, according to models. We'll have to wait and see how challenging the diaphites are.

Lessons acquired from lonsdaleite, according to the scientists, might be applied to other carbon-rich minerals that are subjected to high pressure and include considerable quantities of other elements. These crystals could be used for a variety of purposes, according to co-author Professor Christoph Salzmann from University College London.

"Through the controlled layer growth of structures, it should be possible to design materials that are both ultra-hard and also ductile, as well as have adjustable electronic properties from a conductor to an insulator," he said. According to Salzman, they might be used for "applications ranging from abrasives and electronics to nanomedicine and laser technology." The term lonsdaleite commemorates Dame Kathleen Lonsdale, a trailblazing crystallographer and campaigner who established the flatness of the hexagonal benzene ring.