what’s the difference between hardness and strength when talking about diamonds?

Question

Why would I be able to smash a diamond with a hammer but I cant scratch it?

In: Geology

Answer 1

Take a thin wine glass. Try making a scratch on it with just your fingernails. You can’t – because glass is harder than your fingernails. Imagine (don’t do this!) squeezing it hard with your fingers – you will probably break the glass because you exceed the tensile strength of the glass and glass isn’t very ductile.