1. Color:
* Pros: Easy to observe.
* Cons: Highly variable within a single mineral species, can be misleading.
2. Streak:
* Pros: Color of the mineral's powder, often more consistent than its external color.
* Cons: Not all minerals leave a streak.
3. Luster:
* Pros: Describes how light reflects off the surface (metallic, glassy, pearly, etc.). Helpful for distinguishing between broad groups of minerals.
* Cons: Can be subjective, may be similar in different minerals.
4. Hardness:
* Pros: Measured using the Mohs Hardness Scale (1-10), a reliable indicator of mineral identity.
* Cons: Requires a scratch test which can damage the mineral.
5. Cleavage and Fracture:
* Pros: Describes how a mineral breaks. Cleavage is a clean, flat break along planes of weakness. Fracture is an irregular break.
* Cons: May require a sample that can be broken.
6. Crystal Form:
* Pros: The external shape of the mineral. Well-formed crystals are often distinctive.
* Cons: Many minerals don't form well-defined crystals.
7. Specific Gravity:
* Pros: Density of the mineral relative to water. Can be a good identifier.
* Cons: Requires a precise measurement and a scale.
8. Magnetism:
* Pros: A simple test to identify magnetic minerals (e.g., magnetite).
* Cons: Only useful for a few minerals.
9. Other Properties:
* Fluorescence: Some minerals glow under UV light.
* Smell: Some minerals have a characteristic odor.
* Taste: Certain minerals are soluble and have a recognizable taste (caution: never taste a mineral unless you're certain it's safe).
Important Note: It's often best to use multiple properties for accurate mineral identification. Don't rely on just one property.