"Laboratory Synthesis of 'Meteorite Diamond' for the First Time: The Identity and Potential of 'Hexagonal Diamond (Lonsdaleite)'"

A research team from the Center for High Pressure Science and Technology Advanced Research (HPSTAR) in Beijing, China, has successfully created a "bulk, sizable" sample of "hexagonal diamond (lonsdaleite, also known as 'meteorite diamond')" in a laboratory for the first time. The study was published in Nature on July 30, 2025. The researchers used diamond anvil cells and large multi-anvil presses to compress and heat purified graphite under conditions exceeding 20 GPa and 1400°C, transforming it into a hexagonal structure and obtaining a disk-shaped sample that can be recovered at room temperature and normal pressure. Previously, only nanocrystals with impurities of meteorite origin were available, making it difficult to evaluate their properties. This achievement clarifies that "hexagonal diamond is an independent crystal phase." Theoretically, it is considered to be up to 58% harder than regular diamond, although the actual hardness of the current bulk sample is only "slightly higher." Future efforts will focus on increasing purity and size. Industrial applications (such as ultra-hard tools, thermal management, and quantum technology) are projected over a 10-year span.