Diamonds are the hardest natural material found on Earth. No other natural substance can scratch a diamond—except another diamond. That’s why diamonds are often used in cutting tools, industrial equipment, and jewelry.
Diamonds form deep underground, where heat and pressure combine to turn carbon into this incredibly tough crystal. Over time, volcanic activity brings them closer to the surface, where they can be mined. Their strength comes from how the carbon atoms are tightly packed and bonded together.
While scientists have discovered a few rare materials, like lonsdaleite (found in some meteorites), that might be slightly harder than diamonds, these are not common on Earth. Also, some lab-created materials may outmatch diamonds in certain conditions, but when it comes to natural substances found on our planet, diamonds still hold the crown for hardness.
That said, being hard doesn’t mean diamonds are unbreakable. They can chip or even shatter if struck in the right spot with enough force. So, while they resist scratching extremely well, they still need to be handled with care.
