A mineral is scratched by apatite but not by calcite. What could its hardness value be?

Question

Responses
1
2
4
6

Answer 1

To determine the hardness value of the mineral, we can refer to the Mohs scale of mineral hardness.

Apatite has a hardness of 5, and calcite has a hardness of 3. If the mineral can be scratched by apatite, its hardness must be less than 5. If it cannot be scratched by calcite, its hardness must be greater than 3.

Therefore, the possible hardness value for the mineral is likely to be 4.