What Are Rocks, Minerals, And Elements?
It is best if we clearly define what we are talking about when we discuss rocks, minerals and elements.
Elements are atoms, the smallest piece that we can split matter into (except for subatomic particles and other things that we'll leave to the physicists). Different elements have different properties. Take two different elements: iron and helium. Iron is very different than helium. You wouldn't fill a balloon with iron any more than you would try to build a bridge out of helium.
Elements often are stacked together with other elements to form minerals. Minerals are simply a collection of one or more elements that are stacked neatly together in a form called a crystal structure. More details are available about this.
Rocks are a composed of one or more minerals. A rock can be made up of only one mineral or, as shown in the figure, a rock can be made up of a number of different minerals.
So, rocks are composed of one or more minerals and minerals are composed of one or more elements.