Rock Cycle
Elementary School
Definition
The continuous process by which rocks are formed, broken down, and reformed over long periods of time. Through melting, cooling, weathering, and pressure, one type of rock can gradually become another, recycling Earth's materials.
Worked examples
Granite (igneous) weathers into sediment → compacts into sandstone (sedimentary) → heat and pressure form quartzite (metamorphic) → melts into magma → cools back into granite.
A complete cycle showing how one rock type transforms into another through different Earth processes.
Limestone (sedimentary) buried deep underground experiences intense heat and pressure, recrystallizing into marble (metamorphic).
Metamorphism changes existing rock without melting it, creating a new rock type.
Common mistakes
- The rock cycle happens quickly, within days or weeks → The rock cycle takes millions of years to complete Rock transformation requires geological time scales—weathering, burial, heat, and pressure all work extremely slowly.
- Rocks must go through all three types in order: igneous → sedimentary → metamorphic → Any rock type can transform into any other type through different pathways The cycle is not linear; sedimentary can melt to igneous, metamorphic can weather to sedimentary, etc.
- Once a rock becomes metamorphic, it cannot change anymore → Metamorphic rocks can melt, weather, or undergo further metamorphism The rock cycle is continuous—no rock type is a final endpoint.
Where you'll use it next
You'll apply the rock cycle when studying plate tectonics, mountain formation, and Earth's history in geology units, and it connects to soil formation and natural resources in environmental science.
See also
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026