Select the one substance that is not a mineral.

 - Hornblende is formed in nature. It is a pure substance.
 - Diamond is a pure substance. It is formed in nature.
 - Candle wax is not a pure substance. It is made by humans.
Compare the properties of each substance to the properties of minerals. Select the substance whose properties do not match those of minerals.
Candle wax is not a pure substance. But all minerals are pure substances.
Candle wax is made by humans. But minerals are not made by living things.
So, candle wax is not a mineral.
Diamond is a mineral.
Hornblende is a mineral.