1. Naturally Occurring: Minerals must form through natural processes, not man-made.
2. Inorganic: Minerals cannot be formed from living organisms.
3. Solid: Minerals are solid at room temperature.
4. Definite Chemical Composition: Each mineral has a specific chemical formula, though there can be slight variations within that formula.
5. Crystalline Structure: Minerals have an orderly, repeating arrangement of atoms. This arrangement can result in distinctive crystal shapes, although not all minerals form visible crystals.
