Where do Rocks Come From?

Did you know pencil lead is a mixture of graphite and clay? Page 18, A Look at Minerals

Igneous Rocks

From volcanoes!
Magma hot melted rocks in a volcano gets blown out. We call it lava. Lava gets cooled down to form igneous rocks. Page 4, What are Igneous Rocks

Fault lines are where volcanoes form, when magma is forced into them. Page 10, A Look at Igneous Rocks

Extrusive igneous rocks are made above the ground. Intrusive igneous rocks form underground. Page 23, Weird but True

Pumice rocks are a kind of extrusive igneous rock and they are the only rocks that float. Page 23, Weird but true

Granite is the most common intrusive igneous rock. page 24, Weird but True

Did you know the word igneous comes from the Latin word ignis, which means fire? Page 11, A Look At Igneous Rocks

Sedimentary Rocks

Water carries grains of rock: gravel, sand, silt, and clay. The grains of rock go together. Page 26, Everything Rocks and Minerals

Limestone is a kind of sedimentary rock. It's made out of ancient shellfish. Page 50, Weird but True

Did you know The Amazon River puts 3 tonnes of grains of rock in the ocean every day! Page 14, A Look at Erosion and Weathering

Metamorphic Rocks

Made inside Earth by pressure and heat, which change the rocks. Page 25, Everything Rocks and Minerals

When metamorphic rocks get forced into wavy lines, they look striped, and these are foliated metamorphic rocks. Nonfoliated metamorphic rocks do not have wavy lines and are not striped. Page 18, A Look at Metamorphic Rocks

Gneiss is a foliated rock made from granite, with many coloured stripes in it. Page 20, A Look at Metamorphic Rocks

Quartzite is a nonfoliated rock made from sandstone. Page 22, A Look at Metamorphic Rocks

Did you know quartzite can be red, pink, orange, green, or blue when there are things in the sandstone it is made from? Page 25, A Look at Metamorphic Rocks

The Rock Cycle

The rock cycle starts when magma from a volcano becomes igneous rock. Erosion breaks them down into smaller pieces which can join up to make sedimentary rocks. Sedimentary or Igneous rocks can be changed by pressure and heat to be metamorphic rocks. The rocks melt and become magma again. Page 8, A Look at Erosion and Weather