1. Chemical Composition: The elements that make up the mineral. This is the most fundamental characteristic, as it defines the mineral's chemical formula.

2. Crystal Structure: The orderly arrangement of atoms within the mineral. This structure can be observed using a microscope or X-ray diffraction.

3. Hardness: A mineral's resistance to scratching. This is measured using Mohs Hardness Scale, which ranges from 1 (talc) to 10 (diamond).

4. Cleavage: The tendency of a mineral to break along specific planes of weakness. This creates smooth, flat surfaces.

5. Fracture: The way a mineral breaks when it does not cleave. This can be irregular, conchoidal (curved), or splintery.

6. Luster: The way a mineral reflects light. This can be metallic, glassy, pearly, or dull.

7. Color: While color can be useful for identification, it is often unreliable as impurities can alter the color of a mineral.

8. Streak: The color of the mineral's powder when rubbed on a streak plate. This can be a more reliable identifier than color, as it is less affected by impurities.

These characteristics are used in combination to identify and classify minerals.