Compare the properties of each substance to the properties of rocks. Select the substance whose properties do not match those of rocks.
Trachyte is a rock.
Gneiss is a rock.
A turtle shell is made by a living thing. But rocks are not made by living things.
So, a turtle shell is not a rock.
Select the one substance that is not a rock.
A: Gneiss is formed in nature. It is a solid.
B: A turtle shell is made by a living thing. It is formed in nature.
C: Trachyte is formed in nature. It is not made by living things.