New Material Harder Than Diamond

Hardness is not measured in GPa.
Physicists tend to ignore common engineering standards.
Michael Dahms

The article stated, in the first line: It is almost universal to refer to hardness as the result of indentation which involves plastic flow, or scratching which involves some form of fracture.
Hardness as "Isothermal Bulk Modulus" probably doesn't mean what you think it means.
Theoretically, you could achieve this narrow definition of hardness by somehow straightening the carbon to carbon bond load path (in allthree directions at once), and if you think about the article and what it says, you can see that the configuration they describe MAY do that.
Press releases are just press releases... That is quite important to remember.
Read the full paper, like a real scientist would, and then make up your mind.
But feel free to endlessly speculate..
All that endless speculation occurred over a decade ago with "Buckyballs", "Diamond Like coatings" and so on.
IF you remember all that wonderful hype.
snipped-for-privacy@yahoo.com wrote:

Well it could be and is sometimes. Heteronuclear diamond goes up to ~105 GPa. I wonder how tough ballas gets.
-Aut

^^^^^^^ That's not a hardness but a stiffness. Toughness is a different property as well.
Michael Dahms

"The group created the ADNRs by compressing the carbon-60 molecules to 20 GPa, which is nearly 200 times atmospheric pressure..."
The problem with physicists is that being off by three orders of magnitude is considered acceptable. 20GPa = 197385 atm.

Wrong, it's much lower than the moduli. Indentation tables are easily converted into stress tables.
-Aut

The are only easily convertet, if you now the conversion rule. There is no general conversion rule.
Michael Dahms