how are rocks and soil classified for kids
The foundation of a great rock collection is to identify your rocks by type. Geologist classify rocks into three basic groups based on how they were formed in nature. The types of rocks are: 1  Igneous.2  Sedimentary.etamorphic rocks are formed when sedimentary or igneous rocks are exposed to conditions of very high pressure or temperature, or are exposed to large amounts of very hot water. Slate is formed when fine-grained sedimentary rock (shale) is buried and exposed to high pressure deep beneath the Earth's surface.