Diamond has long be heralded as the hardest (naturally occurring) material, but it has officially lost that title to lonsdaleite. In fact, diamond now ranks third on the list behind lonsdaleite and wurtzite boron nitride - 58% and 18% harder than diamond, respectively.
If you’ve never heard of them that’s because they are very rare. Lonsdaleite is only sometimes formed when meteorites hit the Earth, and wurtzite boron nitride is produced in extremely high temperature and pressure volcanoes. The materials are so scarce that researchers do not even have enough to perform an actual experiment. The hardnesses for the two materials were predicted using computer modeling of their atomic bonding.
Hardness is a pretty significant materials property, and hard materials like diamond have many practical applications besides jewelry. Diamonds, for instance, are often used in cutting, drilling, grinding, and polishing applications. Researchers say wurtzite boron nitride could be the more commercially viable of the two materials. Though not as hard as lonsdaleite, this boron nitride is stable at higher temperatures than diamond.
I have mixed feelings. It is always exciting when a new material or material property is discovered, but I always took it for granted that diamond was the hardest material. It’s a “10″ on the Mohs hardness scale, for Pete’s sake. I don’t know what to believe now. Next thing you know, they’ll be saying that the spontaneous change in entropy of a system and its surroundings can be negative. And that’s just crazy talk!
Source: New Scientist
Been listening to this one a lot, pretty much the whole way through.
This novel was published after the Chilean-Mexican author's death, and I'm not even sure if it was entirely finished or not. It is broken up into five parts which, while connected, stand pretty much on there own. I have not yet made it to the grim part about the murders of hundreds of women in Mexico, so I have so far found it enjoyable and even funny despite some dark underpinnings. It's had a ton of critical praise, and I like it much more than my last foray into the violent novel genre: Blood Meridian.
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“It’s a “10″ on the Mohs hardness scale”
I guess lonsdaleite goes to 11.
Ha! Good point.
I do wonder, though, whether they will adjust or extend the scale. Probably not since these materials are so rare and at this point of no real use to anybody. That could change though if they can be created synthetically, or other materials are created that mimic their atomic structure.
And on top of all that the Mohs scale is not really that important or useful in a practical sort of way other than as a qualitative comparison.