The harder and rarer the crystal, the more valuable it is. Or is it?
Diamonds have a unique appeal as a way to exhibit status, desirability, and unbridled material excess. But the superstrong mineral is also used on the edges of cutting tools, superpowered drill bits, and even as an industrial abrasive. But now scientists have forged a crystal with even harder properties than the diamonds of your dreams.
A group of researchers has developed a material called lonsdaleite, also called hexagonal diamond, in large enough quantities to study and analyze. And the team found it to be stronger than diamond, according to a recent study published in the journal Physical Review Letters.
In other words, diamonds may soon be surpassed by something harder.
Lonsdaleite is stiffer than conventional diamonds
"Diamond is a very unique material," said Director of the Institute for Shock Physics Yogendra Gupta, who is also an author of the study, in a SciTech Daily report. "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." Gupta's research team used compressed gas and gunpowder to launch graphite discs the size of dimes at a transparent material. At an ear-screeching 15,000 mph (24,140 km/h).
And, when the graphite discs made impact, the shock waves transformed the discs into lonsdaleite. The strength of the newly-formed material was measured with sound waves, which travel more rapidly through stiffer (or denser) material. Just after the discs were struck, the scientists created a small sound wave, and tracked its motion through the diamond with lasers. The data clearly showed that lonsdaleite is more stiff than diamond.
Hexagonal diamond development might open new paths for 'sustainable luxury'
And, upon further analysis, the scientists found that lonsdaleite is a whopping 58% stronger than diamond — breaking the record. But in case you're worried about replacing family diamonds, don't. The lonsdaleite only remained stable for a few short nanoseconds before the high-velocity impact completely destroyed the gem. If Gupta and the research team can find a way to prolong the hexagonal diamond's existence, however, they might rise to kick diamonds down in status. "If someday we can produce them and polish them, I think they'd be more in-demand than cubic diamonds," he said, in the report. "If somebody said to you, 'look, I'm going to give you the choice of two diamonds: one is a lot rarer than the other one.' Which one would you pick?"
And, there could be an extra incentive to make these ultra-hard super-diamonds a mass-produced alternative. In May, the world's largest jeweler, Pandora, declared the end of mined diamond sales, with plans to pivot to using exclusively lab-made diamonds. On paper, this is really great since diamond mines are ethically questionable at best. But, while lab-grown diamonds can reduce the environmental effects of manufacturing the gems, the lab-grown method often still uses coal for power. Consequently, diamond-makers like Diamond Foundry in the U.S. are aiming for a hydro-powered, zero-emission production process. But if we could choose between mostly sustainable lab-grown diamonds, and hexagonal diamonds with more stiffness and resilience, more people might prefer the latter.