Rocks vs. Minerals
Rocks are composed of 2 or more minerals or substances. They are similar to minerals in that they must be solid and occur naturally. Rocks are different in that they can be organic (or inorganic), they can have a crystalline structure but they do not always have one, and they have no specific chemical formula (they are mixtures of many formulae).
To the left is a Venn Diagram that summarizes Rocks vs. Minerals
To the left is a Venn Diagram that summarizes Rocks vs. Minerals