Final answer:
Rocks are composed of minerals, which can be a mixture of different types of minerals or grains. For example, when breaking apart granite, it contains small pieces of quartz, feldspar, and mica. Rocks can be categorized into three basic types: igneous, sedimentary, and metamorphic.
Step-by-step explanation:
Rocks are made of minerals. Rocks can be a mixture of different kinds of minerals, a mixture of many grains of the same kind of mineral, or a mixture of different grains of rocks. When you split a rock into very small pieces, the pieces are different from each other. For example, when you break granite apart, you get small pieces of quartz (clear), feldspar (pink or white), and mica (black). When you split a mineral into pieces, you still have pieces of the same mineral. If you break a big chunk of quartz into smaller pieces, you still have pieces of quartz.
There are three basic rock types: Igneous, sedimentary, and metamorphic.