[blix]

Materials Scientist here.

There are no small-scale diamonds present in the material. On the small scale, the material is a carbon glass (an unordered, or amorphous solid), distinct from diamond, which is an ordered crystal. Typically, high density glasses are stronger than crystals made from the same elements, so the strength of the material isn't particularly surprising, rather it's the processing of the new material that is novel.

It's also worth noting that this isn't even the first carbon-based material stronger than diamond. Lonsdaleite is a closely related structure that is significantly stronger. It is much less common, however, naturally occurring only in meteorites.

[hypnocode]

Any idea as to which one is actually harder, the new material, or Lonsdaleite? I see from this journal that Lonsdaleite has 58% higher indentation strength than diamond: http://prl.aps.org/abstract/PRL/v102/i5/e055503 but I couldn't find figures for the new material.