Currently, diamond is regarded to be one of the hardest and most scratch-resistant natural materials in the world. Most diamonds found in nature and often used in jewelry display a cubic crystal structure, a repeating pattern of 8 atoms forming a cube with carbon atoms at its vertices. Each carbon atom forms four bonds with its neighbors, explaining the overall stability and hardness of the crystal structure.
Now scientists at Washington State University’s Institute for Shock Physics created hexagonal diamonds large enough to measure their stiffness and also calculated their hardness. The results of their experiments are published in a recent issue of Physical Review Letters.
“Diamond is a very unique material,” said Yogendra Gupta, director of the Institute for Shock Physics and corresponding author on the study. “It is not only the strongest—it has beautiful optical properties and a very high thermal conductivity. Now we have made the hexagonal form of diamond, produced under shock compression experiments, that is significantly stiffer and stronger than regular gem diamonds.”