Chinese researchers have synthesized hexagonal diamonds that mirror the rare lonsdaleite found in the Canyon Diablo meteorite—and they’re tougher than the typical Earth-grown gems. Unlike conventional cubic diamonds with their orderly lattice, these diamonds show off a unique honeycomb structure, first discovered in a meteorite that hit Arizona about 50,000 years ago.
This breakthrough emerged from a collaboration between the Centre for High Pressure Science and Technology Advanced Research and the Chinese Academy of Sciences’ Xian Institute of Optics and Precision Mechanics. By starting with extremely pure single‑crystal graphite and applying high pressure and temperature under quasi‑hydrostatic conditions, the team successfully steered clear of ending up with ordinary cubic structures. Real‑time X‑ray techniques let them monitor the process as macroscopic hexagonal diamond crystals—roughly 100 micrometres in size, about the width of a human hair—grew in the lab.
Such precision finally settles a long‑standing debate about the existence of pure meteorite diamonds; previous efforts often resulted in mixed crystal phases or the standard cubic form. With hardness estimated at up to 60% greater than traditional diamonds, these lab‑crafted gems open up possibilities for advanced applications, from cutting tools and wear‑resistant coatings to high‑end electronics that benefit from superior thermal conductivity.
Ho‑kwang Mao from the Chinese Academy of Sciences remarked that these hexagonal diamonds could pave the way for next‑generation superhard materials and electronic devices. The findings, detailed in Nature, offer a promising glimpse into the future of material science.
