Diamonds are Weak
Diamonds are widely considered to be one of the strongest materials on Earth, scoring a whopping 10 on the Mohs scale. For reference, the Mohs scale ranks minerals based on how hard they are and a 10 is the highest score. That being said, diamonds are no longer the strongest material on earth. That spot would belong to something called Lonsdaleite. This material has a similar arrangement as diamond at the molecular level, as it is made up of carbon. Its indentation strength is a whopping 152 GPa (Billions of pascals). For comparison, diamond has an indentation strength of 97 GPa, which makes Lonsdaleite 58% stronger.
However, if we look at the question of the strongest material from a universal perspective, things get a lot crazier. Thousands of miles from Earth lies the strongest material in the universe, nuclear pasta. Of course, this is not actual pasta and instead refers to the crust of a neutron star. The “pasta” part of this term comes from the fact that the way the material of the star is woven through the crust resembles spaghetti, lasagna, or gnocchi. Neutron stars are born after a supernova, which causes bodies the size of the sun to be compressed into the size of a city. This makes them 100 trillion times denser than anything on Earth.
Source:
https://www.mcgill.ca/newsroom/channels/news/nuclear-pasta-hardest-known-substance-universe-289729
