Scientists Claim They’ve Finally Made the Elusive ‘Hexagonal’ Diamond
9th March 2026
In 1962, researchers hypothesized that diamond’s known form—a mostly cubic crystal—wasn’t the coveted mineral at its greatest hardness. Ever since, researchers have strived to recreate a hexagonal diamond, claimed to be roughly 50% harder than a regular diamond. But a new finding by Chinese researchers may finally bring this race to an end.
A Nature paper published yesterday describes the synthesis of a “millimeter-sized, phase-pure hexagonal diamond,” made with a highly specific method of compressing graphite at elevated temperatures. The resulting diamond, roughly 0.04 inches (1 millimeter) in size, was slightly harder, stiffer, and more resistant to oxidation compared to cubic diamonds.
What’s more, the team scrutinized their product with X-rays and atomic-scale microscopes, confirming that the crystal’s structure was hexagonal with minimum defects. Overall, this result may provide the strongest evidence thus far that hexagonal diamonds can exist, the team says.
Lucky us.