Science Monday: Are Diamonds Really Hard?

Diamonds are the hardest substance on earth… right? Or could I break one with my foot?

Diamonds — you can’t eat them, but man, they’re sparkly and pretty to look at.

Most people know two facts about diamonds: they’re a girl’s best friend, and they’re the hardest rock on Earth.

That incredible hardness is one of the reasons why they’re so wildly popular for jewelry. The notion that “diamonds are forever” drives millions of dollars in jewelry sales, as if any other, lesser gemstone will break down and degrade, while the diamond remains intact and pure.

“Oh honey, you bought me DIAMONDS for my drill? You shouldn’t have!” Source.

We also see diamonds used for less beauty-focused, more industrial purposes, to take advantage of their hardness. Many cutting tools, including saw blades, drill bits, and engraving tools, are tipped with diamond to increase their cutting power.

So, while we can’t scientifically prove that a diamond is a girl’s best friend, it does seem like a pretty widely accepted fact that diamonds are the hardest substance. They can scratch and cut practically any other material, including steel and tungsten carbide.

But are these incredibly tough gems actually very fragile? Is this the secret that the De Beers cartel doesn’t want you to know — that…