These are also very expensive, but not a patch on the more expensive substances in the world.

Industrial materials such as platinum or tritium, which are used to make luminous signs, are higher up the list.

There are also more illicit substances such as cocaine, heroin, and LSD which all command very high prices per gram.

But none of these is a patch on a material which can sell for as much as $140 million per gram.

So what on earth is this substance which can fetch such an insanely high price?

It's been given the catchy name of 'Nitrogen Atom-Based Endohedral Fullerenes'. Now say that backwards five times.

But why is Nitrogen Atom-Based Endohedral Fullerenes so enormously expensive?

It's because of what the material could be used for in the future, or rather what technology it might enable us to develop.

You see, Nitrogen Atom-Based Endohedral Fullerenes has the potential to be used to create very small highly accurate atomic clocks.

Atomic clocks are a crucial part of how GPS systems work, making them hugely important to navigation.

The problem is that at the moment atomic clocks are rather large, we're talking the size of a room.

But using Nitrogen Atom-Based Endohedral Fullerenes could help to make current atomic clocks look like the old IBM computers next to a modern smartphone.

That could have massive implications for how we use atomic clocks as well, expanding their use beyond navigation.

A small enough atomic clock could be used to pinpoint the location of something extremely accurately, as well as eliminating GPS blind spots by having an on-board atomic clock.

Nitrogen Atom-Based Endohedral Fullerenes has been developed by Oxford scientists at Designer Carbon Materials and they reckon that in the future even smartphones could have an atomic clock inside them.

Interestingly the name of the material, specifically the 'fullerenes' part, is directly related to its structure.

This is a 'cage' of carbon atoms with a nitrogen atom inside them.

The name 'fullerene' refers to this 'cage' and is a nod to architect and philosopher Richard Buckminster Fuller, who was known for his designs featuring distinctive interlocking triangles in a geodesic dome.