However, it's important to note that carbon exists in many different forms (called allotropes), each with different properties. Here are some examples:

* Diamond: The hardest known natural material, a solid.

* Graphite: A soft, slippery solid used in pencils and lubricants.

* Buckminsterfullerene (C60): A spherical molecule, a solid.

* Carbon nanotubes: Long, cylindrical molecules, a solid.

While carbon is usually solid, it can exist in other states under extreme conditions:

* Liquid carbon: Can be formed at extremely high temperatures and pressures, such as in the Earth's core.

* Gaseous carbon: Exists in very high temperatures, like in stars or during combustion.