Use table to answer question.
MINERAL/ HARDNESS
Obsidian. 5
Halite. 2.5
Flourite. 4
CLEAVAGE/FRACTURE /LUSTER
Fracture. Vitreous
Cubic cleavage. Vitreous
Pctohedral. Vitreous
An unknown mineral specimen is not scratched by a penny and does not exhibit cleavage. This mineral is most likely to be:
a. obsidian
b. halite
c. fluorite
Based on the information provided, the unknown mineral specimen is most likely to be obsidian since it is the only mineral listed that has a hardness of 5 and does not exhibit cleavage.
To determine the most likely mineral based on the given information, we need to consider both hardness and cleavage.
First, let's refer to the table provided:
MINERAL / HARDNESS
Obsidian - 5
Halite - 2.5
Fluorite - 4
CLEAVAGE / FRACTURE / LUSTER
Fracture - Vitreous
Cubic cleavage - Vitreous
Pctohedral - Vitreous
Now, let's analyze the given information:
1. The unknown mineral is not scratched by a penny.
2. The unknown mineral does not exhibit cleavage.
Based on the information provided, we can conclude that the mineral has a hardness greater than or equal to 3. Since the penny has a hardness of 3.5, any mineral that cannot be scratched by a penny will have a hardness greater than 3.5.
Looking at the table, the only mineral with a hardness greater than 3.5 is obsidian, which has a hardness of 5. Additionally, obsidian does not exhibit cleavage. Therefore, the most likely mineral in this case is a. obsidian.
So, the answer is a. obsidian.
To determine the most likely mineral specimen, we will use the information provided:
- Obsidian: Hardness of 5
- Halite: Hardness of 2.5
- Fluorite: Hardness of 4
From the information given, we know that the unknown mineral is not scratched by a penny, which means its hardness must be greater than 3. Also, it does not exhibit cleavage.
Comparing the hardness values, we can eliminate halite since its hardness is below 3.
So, the most likely mineral specimen is:
c. fluorite