* Naturally occurring: Minerals are formed by natural processes, not man-made.

* Inorganic: They are not derived from living organisms.

* Solid: They have a definite shape and volume.

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

* Definite chemical composition: Each mineral has a specific formula (e.g., quartz is SiO2).

* Specific physical properties: Minerals can be identified by their color, streak, luster, hardness, cleavage, fracture, density, and magnetism.

These properties are crucial for identifying and classifying different minerals.