China produces pure hexagonal diamond and claims superior hardness over regular diamond

Chinese researchers created small, pure hexagonal diamond (lonsdaleite) samples and demonstrated that it is stiffer and harder than cubic diamond and more oxidation-resistant; the 1.5 mm samples were formed by compressing organized graphite at about 20 GPa for 10 hours and heating to roughly 1,300–1,900°C, with the work published in Nature, indicating a feasible bulk production method and potential industrial applications in drilling, cutting, and thermal management.