Select the one substance that is not a rock.
A: Basalt is not made by living things. It is a solid.
B: Quartzite is not a pure substance. It is formed in nature.
C: Soap is made by humans. It is a solid.
Compare the properties of each substance to the properties of rocks. Select the substance whose properties do not match those of rocks.
Soap is made by humans. But rocks are not made by living things.
So, soap is not a rock.
Basalt is a rock.
Quartzite is a rock.