China creates rare meteorite diamonds much harder than ones on Earth

Chinese scientists have successfully synthesized rare hexagonal diamonds, known as lonsdaleite, which are much harder than the conventional cubic diamonds typically found on Earth. These hexagonal diamonds were first discovered in the Canyon Diablo meteorite, which struck Earth around 50,000 years ago. Unlike the cubic structure formed deep within Earth under high temperature and pressure, lonsdaleite forms under the extreme conditions of meteorite impacts, giving it a unique honeycomb-like atomic arrangement and potentially up to 60% greater hardness. The breakthrough was achieved by a joint team from the Centre for High Pressure Science and Technology Advanced Research and the Chinese Academy of Sciences. They used ultra-pure single-crystal graphite and applied uniform high pressure and temperature while monitoring the transformation with in-situ X-ray techniques. This approach minimized impurities and prevented the material from reverting to the cubic diamond structure, allowing the creation of pure hexagonal diamond crystals about 100 micrometers wide. This marks the first macroscopic proof of lons