Diamond has a Successor:Strongest material on Earth

When any one is asked "Which is the toughest material on the Earth?", The most expected answer will be diamond. Yes it is, Diamond is the hardest material known to man. Its an allotrope of Carbon. 

Diamond

The tetrahedral structure of diamond and the strong sp3 bonds the carbons make, is the reason why diamond is so strong. Since all the vacant valencies are satisfied in the atom, diamond is highly stable. Diamond is preferred because of its high thermal conductivity and toughness. It is used in blades of drilling machines, since its hardness can cut any type of materials.

But with the advancement of Science and Technology, together with the increasing costs of diamonds the search for tough materials other than diamond started. In this course, with the introduction of new materials that were developed from the chemical father of diamond: carbon, i.e., new isotopes of carbons the search took a pause. These were the materials of the thickness of 1 nm. Hence they were called Nano materials. Graphene was the new material developed that was tougher than diamond to consider.

Graphene Sheet

Graphene is an isotope of Graphite Carbon. It is a honey Comb lattice structure consisting of sheets of Carbon atoms of just one atom thick. The Carbons of Graphite are bonded in sp2 manner. It was made by rubbing the Graphite planes with adhesive tape!

In addition to these nano materials another rarely occurring natural substance has overcome the toughness of Diamond: it was expected to be 58% harder than diamond!!!

It was wurtzite boron nitride and mineral lonsdaleite. These were the two minerals which had the properties much better than diamond. Lonsdaleite, also called Hexagonal Diamond has 58% more stress withstanding quality than diamond. 

Structure of Lonsdaleite

But the thing is that these minerals are so rear that there is no sufficient amount of them, even to test them. In such a case, its obvious to think that Diamond is the only, so what sufficiently available toughest mineral on earth.