Question: If one mineral can scratch another mineral then that other mineral is softer than that one mineral, as can be tested with
Choices:
text: a diamond and steel
label: A
text: a rock and glass
label: B
text: a diamond and agate
label: C
text: a ruby and salt
label: D
Answer: C
Fact: if one mineral can scratch another mineral then that other mineral is softer than that one mineral