Are diamonds harder than metal?

Question

I was wondering which is harder. Because they say diamonds are really hard, but I didn't know if metal or iron was harder.

Answer 1

Yes, diamonds are harder -- so hard, in fact, that it took until 2006 before we found a synthetic substance that was at all harder.  Ultrahard fullerite, which like diamond is just a crystalline form of carbon, has an estimated hardness 1.17-1.52 times that of diamond.

Answer 2

The reason why diamonds are so hard is because of their structure; the crystalline structure of diamonds is extremely regular and very difficult to break by various means.

On the other hand, metals have periodical breaks in regular structure which causes the existence of "weak points" in the structure.

Answer 3

Yes, diamonds are the hardest rock on the earth. The only way to cut a diamond is to use another diamond.