List and define the principal physical properties used to identify a mineral. (E)

The principal physical properties used to identify a mineral include: 1. Color: The visible hue of a mineral, although it can be unreliable due to impurities. 2. Luster: The way a mineral reflects light, categorized as metallic or non-metallic. 3. Hardness: The mineral's resistance to scratching, measured using Mohs scale (1-10). 4. Streak: The color of a mineral's powdered form, determined by rubbing it across a streak plate. 5. Crystal Form: The natural shape of a mineral determined by its internal crystalline structure. 6. Cleavage: A mineral's tendency to break along flat, smooth surfaces due to weak crystal structure points. 7. Fracture: How a mineral breaks when it doesn't exhibit cleavage, occurring irregularly. 8. Specific Gravity: A measure of a mineral's density relative to water, comparing the mass of the mineral to the mass of an equal volume of water.