Asked by Bornana

Why is coal not classified as a mineral?

A. It is does not occur naturally.

B. It is not a solid.

C. It has no crystal shape.

D. It is made of organic material.
Answered by Bornana
Which mineral property is easily observed, but can be unreliable when it comes to mineral identification?

A. cleavage

B. hardness

C. color

D. streak
Answered by Bornana
Which mineral property describes a mineral’s resistance to being scratched?

A. hardness

B. streak

C. fracture

D. cleavage
Answered by Bornana
What is the name for a rock containing valuable minerals that can be mined?

A. an igneous rock

B. a jewel

C. a sedimentary rock

D. an ore
Answered by Bornana
What are elements that lose electrons and form positive ions classified as?

A. nonmetals

B. minerals

C. metals

D. ores
Answered by Bornana
To which crystal system does a halite crystal (rock salt) belong?

A. cubic

B. monoclinic

C. pentagonic

D. tetragonal
Answered by GPT-4o mini
Coal is not classified as a mineral primarily because **D. It is made of organic material.** Unlike minerals, which are typically inorganic and have a definite chemical composition and crystalline structure, coal is formed from the remains of ancient plant materials. This organic aspect is a key reason it does not meet the criteria for classification as a mineral.
Answered by GPT-4o mini
The mineral property that is easily observed but can be unreliable for mineral identification is **C. color**. While color can provide some information about a mineral, it is often influenced by impurities and can vary widely within the same mineral species, making it less reliable for accurate identification.
Answered by GPT-4o mini
The mineral property that describes a mineral’s resistance to being scratched is **A. hardness**. Hardness is measured on the Mohs scale, which ranks minerals based on their ability to scratch one another.
Answered by GPT-4o mini
The name for a rock containing valuable minerals that can be mined is **D. an ore**. Ores are typically mined for the extraction of metals and other valuable substances.
Answered by GPT-4o mini
Elements that lose electrons and form positive ions are classified as **C. metals**. Metals tend to have low electronegativity and readily lose electrons, resulting in the formation of cations (positive ions).
Answered by GPT-4o mini
A halite crystal (rock salt) belongs to the **A. cubic** crystal system. Halite is characterized by its cubic crystal shape, which is a distinctive feature of minerals in the cubic (or isometric) crystal system.