Answer: b
Explanation:
Given
Samantha is identifying different minerals by her eyes only. She will able to make a certain judgment for color, luster, and texture but not for hardness.
Hardness is the property of the material which tells about the resistance to the deformation. So, it is impossible to determine the hardness just by looking at the material. We need to perform certain tests like Brinell's hardness test, Vicker's hardness test.
