A rock is a naturally occurring solid aggregate consisting of one or more minerals/mineraloids.
Rocks can be classified by several characteristics: mineral and chemical composition, texture, color, permeability.
Rock types refer to the group of 3 types of rocks:
- Igneous, rocks that are formed through volcanic activity
- Sedimentary, rocks that are formed by sedimentation of material at the surface and within bodies of water.
- Metamorphic, sedimentary, igneous, or metamorphic rocks that have undergone a major change
Due note; that a rock can hold characteristics of two or three of these types. It is generally classified into the type that it is more closely related to.