Lab-Grown Diamond Breaks Records for Hardness

Diamonds have long been celebrated as the hardest natural material on Earth. However, scientists have recently pushed the boundaries even further, creating a new form of diamond that is tougher than any natural diamond before it. This breakthrough comes through a novel approach to diamond formation, using graphite—a material already known for its hardness—and applying extreme pressure and heat.

The Creation of Hexagonal Diamond

In an innovative experiment, researchers subjected graphite to a staggering pressure and heated it to 1,800 K (1,527 °C or 2,780 °F). This process resulted in a diamond with a rare hexagonal crystal lattice, differing from the usual cubic structure found in both natural and synthetic diamonds.

Hexagonal diamond, also known as lonsdaleite, was first identified over 50 years ago in a meteorite impact site, but it wasn’t until now that solid evidence was gathered to prove its superior hardness. This new diamond created in the lab offers not only an intriguing structural difference but also enhanced properties that have the potential to revolutionize multiple industries.

Unprecedented Hardness and Thermal Stability

The new hexagonal diamond boasts an incredible hardness of 155 gigapascals (GPa), which far exceeds the 110 GPa hardness of natural diamonds. Hardness, measured in gigapascals, indicates the amount of pressure a material can withstand before it deforms, and this synthetic diamond’s ability to withstand such extreme pressure is a game-changer.

Thermal stability is another area where this synthetic diamond excels. Unlike natural diamonds, which can survive higher temperatures only in a vacuum, this synthetic hexagonal diamond can endure temperatures up to 1,100 °C (2,012 °F), significantly higher than the 900 °C threshold of typical nanodiamonds used in industry.

The Future of Diamond Synthesis

This groundbreaking research not only demonstrates that hexagonal diamonds are tougher than their cubic counterparts but also opens the door to the potential mass production of this ultra-hard material. The team found that under extremely high pressures, graphite can be converted into hexagonal diamond with impressive results.

Though much work remains to scale up this synthesis process, the first batch’s remarkable properties suggest that hexagonal diamonds could have applications in industries such as drilling, machinery, and even data storage.

The Road Ahead

This isn’t the first time scientists have attempted to synthesize hexagonal diamonds, but this breakthrough method is a significant step forward. Building on previous experiments, including one in 2016 that used amorphous carbon, this new method has proven successful in creating diamonds with extreme durability.

As research continues, the possibility of harnessing the full potential of hexagonal diamonds is now within reach, offering exciting opportunities for materials science. The findings of this study, published in Nature Materials, could pave the way for the future of industrial and technological advancements using this extraordinary material.