"Crust" doesn't describe a state of matter. It's more of a structural feature found in different objects, like:

* Earth's crust: This is the outermost solid layer of our planet, composed mainly of solid rock.

* Bread crust: This is the outer, hardened layer of bread, formed due to the baking process.

* Pizza crust: Similar to bread crust, it's the crispy bottom layer of a pizza.

So, while the "crust" itself might have different properties, the underlying material is in a solid state of matter.