Diamonds are famously known for being one of the hardest substances on earth – we know you’ve heard the rumor that a real diamond can cut glass. But do you know why diamonds are so hard?
We at GIA have spent a lot of time studying diamonds – we thought it’d be fun to share a small fun fact with you about why diamonds are so hard.
The minerals that create a diamond along with their shape make them the strongest gemstone. Diamonds are made from carbon that has been under extreme pressure and heat found in depths of 87 to 120 miles of the Earth’s mantle, where they are created in during a 1-3.3 billion-year time frame. The heat and pressure causes the diamonds molecules to change so that they’re so close together, the molecules can’t move (known as covalent bonding). The closeness of these molecules forms a rigid bond, therefore making the diamond hard.
Diamonds are rated 10 out of 10 on the Mohs scale of mineral hardness, which characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. The Mohs scale of mineral hardness was created in 1812 by German geologist and mineralogis Friedrich Mohs.