#hexagonal diamond

Diamond is well-known for being the hardest natural material on Earth, though synthetic forms have been developed that are even tougher – a feat that researchers have managed again, through a new approach to diamond formation. The team put graphite (another super-hard material) under an intense amount of pressure, before heating it to 1,800 K (that's 1,527 °C or 2,780 °F). The resulting diamond has a hexagonal lattice crystal structure, rather than the normal cubic structure.

For generations we have grown up believing a simple undisputed rule about the physical world which states that nothing on Earth is harder than a diamond. This glittering clear crystal forged deep in the mantle of our planet has dominated the top of the hardness scale for decades. We use it to cut through solid rock and we put it on drill bits to bore deep into the crust of the Earth. But quietly…