Physical Properties of Minerals

Why is color generally not a reliable characteristic for mineral identification?

• Minerals always have the same color regardless of their composition.

• Many different minerals can share the same visible color, and a single mineral can exist in multiple colors.

• Color can only be observed with specialized equipment.

• The color of a mineral changes too rapidly over time.

What is a mineral's streak, and how is it typically tested?

• The visible color of the mineral, tested by observing it under different lights.

• The color of the mineral in its powdered form, tested by rubbing it against an unglazed ceramic streak plate.

• The way light reflects off its surface, tested by shining a light on it.

• Its hardness, tested by scratching it with another mineral.

What does it mean if a mineral displays cleavage?

• It glows under ultraviolet light

• It has a salty taste

• It is magnetic

• It breaks along smooth, flat planes

How do minerals that display cleavage tend to break?

• Along curved surfaces without a definite shape.

• Randomly, with no predictable pattern.

• Along smooth planes parallel to zones of weak bonding.

• Only when exposed to strong acids.

What does a mineral's hardness refer to?

• Its ability to glow under ultraviolet light.

• Its resistance to being scratched.

• The way it breaks along irregular surfaces.

• Its reaction when exposed to acids.

Halite is also called

• sugar salt

• rock salt

• baking soda

• potash alum

All mineral's physical characteristics are the results of its _____.

• method of extraction

• internal atomic structure and chemical composition

• external appearance

• location of discovery