Minerals

Question 1

What is the difference between a rock and a mineral?

Answer 1

A mineral is a pure substance with a definite chemical structure; a rock is a solid made of one or more minerals.

Question 2

What are the five criteria for a substance to be considered a mineral?

Answer 2

Naturally occurring, solid, inorganic, crystalline structure, specific chemical composition.

Question 3

What does “inorganic” mean in the context of minerals?

Answer 3

It means the substance was not formed by living organisms.

Question 4

What is the Mohs Hardness Scale?

Answer 4

A scale from 1 to 10 that ranks minerals by how easily they can be scratched.

Question 5

Which mineral is the softest on the Mohs scale?

Answer 5

Talc (Hardness = 1)

Question 6

Which mineral is the hardest on the Mohs scale?

Answer 6

Diamond (Hardness = 10)

Question 7

What is “streak” in mineral identification?

Answer 7

The color of a mineral’s powder when rubbed on a porcelain plate.

Question 8

What’s the difference between cleavage and fracture?

Answer 8

Cleavage is breaking along flat planes; fracture is irregular breaking.

Question 9

What is luster?

Answer 9

How a mineral reflects light (e.g., metallic or non-metallic).

Question 10

Which mineral fizzes in acid?

Answer 10

Calcite

Question 11

Which mineral is magnetic?

Answer 11

Magnetite

Question 12

Why is color not a reliable property alone?

Answer 12

Many minerals come in multiple colors due to impurities.

Question 13

What is specific gravity?

Answer 13

The density of a mineral compared to the density of water.