Question

Based on the Mohs Hardness Scale, which mineral could be scratched by a penny but not by a fingernail?
Question 3 options:

A)

Talc

B)

Gypsum

C)

Calcite

D)

Fluorite

Answer 1

To determine which mineral could be scratched by a penny but not by a fingernail based on the Mohs Hardness Scale, we need to consider the hardness values:

- Fingernail: ~2.5
- Penny (made primarily of copper): ~3.0

Now, we analyze the hardness of the minerals given in the options:

A) Talc - Hardness 1 (can be easily scratched by a fingernail)
B) Gypsum - Hardness 2 (can be scratched by a fingernail)
C) Calcite - Hardness 3 (can be scratched by a penny)
D) Fluorite - Hardness 4 (cannot be scratched by a penny)

From this information, the mineral that can be scratched by a penny (hardness 3) but not by a fingernail (hardness 2.5) is:

**C) Calcite**