Four meteorites in northwest Africa were found to contain mysterious hexagonal diamonds that don’t naturally occur on Earth. Essentially, scientists exploring the contents of the space rocks discovered extraterrestrial materials, if you will, alien diamonds. According to Alan Salek, a member of the team that discovered the materials, “some people in the field doubted the existence of this material.” As with regular diamonds, hexagonal diamonds are made of carbon, but their atoms are arranged hexagonally rather than cubically.
The first hexagonal diamonds were recorded in meteorites in the United States and India in the 1960s and were dubbed lonsdaleite. The previously discovered crystals, however, were so small – only nanometres wide – that their hexagonality could not be confirmed. A powerful electron microscope was used by Salek and his colleagues to examine 18 meteorite samples in search of larger crystals. One of them was from Australia, and the other three were from northwestern Africa. It was found that four of the African meteorites contained hexagonal diamonds, some measuring up to a micrometer – about 1,000 times larger than anything previously discovered.
In this way, the team was able to confirm the hexagonal structure’s unusual characteristics. Salek says that now that they have larger crystals, they can get a better understanding of how they form and maybe replicate that process. Scientists are interested in Lonsdaleite since it might have even more industrial potential as a result of its theoretical hardness being stronger than a regular diamond. High-end saw blades, for instance, already contain regular diamonds.
