- Rocks are the oldest things on Earth, found everywhere from cities to oceans and underground.
- Igneous rocks form when magma (melted rock inside Earth) pushes through cracks as lava, then cools and hardens; examples include granite and obsidian.
- Sedimentary rocks form from layers of sand, mud, and pebbles at lake or sea bottoms that press together over time; examples include limestone and sandstone.
- Metamorphic rocks start as other rocks, then change under heat, pressure, and time while buried deep underground; examples include marble and quartzite.
- All rocks constantly change into new rocks over time, so they “live forever” in a cycle.
Parent Tip: Review the logic above to help your child master the concept of summarizing practice worksheet.