The hardest substance on earth are things called Carbon Nanotubes. It's quite some times harder than diamond earning it well above a 10 on the Mohs Scale. This object is synthetic, being made by man. However, there is another substance called Rhenium diboride that is also harder than diamond; another from of a nanotube.
aggregated diamond nanorods are the hardest, least compressible solid known.
they are stronger than diamond
source: Wikipedia
Diamonds are the hardest known substance
Diamond
The hardest known substance that exists is diamond. However, one form of boron nitride is believed to be harder, but it remains theoretical.
No,diamond is the hardest known substance on Earth.
Diamond is the hardest mineral currently known and is an allotrope of carbon.
Diamond is the hardest known substance.
Diamond
The hardness of diamond is a physical property of the diamond. The statement is also untrue as diamond is only the hardest known mineral, not the hardest known substance.
No, diamond is the hardest known natural substance in the world.
Diamond 10
That would be the diamond my friend
Diamond. Curious, perhaps, that the hardest substance known can be shattered - but not scratched or cut.