The first hexagonal-structured diamond was discovered in 1967 within the Canyon Diablo meteorite that hit Arizona 49,000 years ago. It was widely believed to have formed from graphite under the intense heat and pressure generated by the impact with Earth.
While all diamonds consist of carbon atoms, they are not limited to the better-known cubic structure. Research teams from around the world have been trying for years to recreate the hexagonally arranged variant with its distinct atomic stacking.
In an article published on July 30 by the peer-reviewed journal Nature, the Chinese researchers detailed how they achieved high-purity hexagonal diamond crystals of 100 micrometres in size, providing definitive proof of the material’s macroscopic existence.
The team combined expertise from the Centre for High Pressure Science and Technology Advanced Research and the Chinese Academy of Sciences’ Xian Institute of Optics and Precision Mechanics.
While other teams around the world claimed to have synthesised the material, previous attempts typically yielded cubic diamonds or mixed-phase samples rather than pure hexagonal structures, according to the paper’s corresponding author Luo Duan.
