Lesson 2: Rocks Rock!

Getting Started

Questions to Explore

  • How are rocks similar and different?
  • How do scientists discover and describe similarities and differences among Earth materials?

Facts and Definitions

  • Magma is hot, melted (molten) rock below the Earth's surface.
  • Igneous rock is formed by the solidification and cooling of magma.
  • Sedimentary rocks are formed when small pieces of rock, called sediment, pile on top of one another and are pressed together until they harden.
  • Metamorphic rocks are formed from rocks that have undergone extreme heat and pressure deep within the Earth.
  • Weathering is the breaking of rocks into smaller pieces, often by wind, water, or extreme temperature.
  • Erosion is when processes like water or wind carry worn-away rocks (sediment) from one place to another.
  • The rock cycle is a process where, over time, rocks can change from one form to another (igneous to sedimentary, for example).


  • Communicate the uses of rocks and minerals. (S)
  • Show that different rocks and minerals have different properties. (S)
  • Use appropriate tools to identify physical properties of matter.
  • Identify effects of events and long-term changes including growth, erosion, dissolving, weathering, and flow. (S)


  • #3 pencil (kit)
  • Everything Rocks and Minerals by Steve Tomecek
  • colored pencils or markers
  • crayon sharpener* (Activity 4 - optional)
  • foil cup (kit)
  • glass bowl
  • glass plate (kit)
  • glue (kit)
  • gravel (kit)
  • heavy book
  • iron
  • iron nail (kit)
  • journal
  • magnet (kit)
  • magnifying glass (kit)
  • measuring spoons
  • penny (kit)
  • permanent marker
  • plastic knife (kit)
  • plastic spoon (kit)
  • ruler
  • sand (kit)
  • small clear cup or bowl
  • small scale or balance
  • streak plate (kit)
  • string (kit)
  • thin towel
  • wax crayons (kit)
  • wax paper (kit)
  • white vinegar

* - denotes an optional material that may or may not be needed


Ask your child if she knows the difference between a rock and a mineral. Explain that a rock is a solid that is typically formed when minerals combine. Most rocks are made up of one or more minerals. Tell your child that over the next few days she will explore the three types of rock — igneous, metamorphic, and sedimentary — and learn how rocks can transform into other rocks over time through the rock cycle.
Reading and Questions
Materials: Everything Rocks and Minerals by Steve Tomecek
Ask your child to read pp. 22-27 in Everything Rocks and Minerals and then answer the following questions.
  1. What is magma? What type of rocks come from magma?
    Magma is hot liquid rock beneath the Earth's surface. Magma forms igneous rocks.
  2. What happens when magma makes it to the Earth's surface?
    It erupts as lava.
  3. How are metamorphic rocks formed?
    Rocks deep underground are exposed to extreme heat and pressure and transform into new rock types.
  4. How do sedimentary rocks form?
    Sediment is deposited into lakes and oceans where bits of sediment pile on top of one another and become compacted together.
  5. How is sediment created?
    Wind, water, and other weather processes break down rocks into smaller pieces.