Here's why:

* Solid: Minerals have a definite shape and volume.

* Inorganic: They are not made up of living organisms or their remains.

* Crystalline structure: The atoms in a mineral are arranged in a specific, repeating pattern.

* Geological processes: Minerals form through natural processes within the Earth, such as cooling magma, precipitation from water, or changes in pressure and temperature.

Let me know if you'd like to know more about minerals!