Igneous

Igneous Rock• Igneous rocks form when melted rock

from deep below the Earth’s surface cools and hardens.

• As it cools the minerals form crystals that looks like grains in the rock.

• Example: Granite

Igneous Rock• Some igneous rocks form when melted rock

flows onto the Earth’s surface through an opening called a volcano.

• This rock cools very quickly and has very small crystals, or none at all.

• Example: Obsidian, Basalt, and Pumice

Sedimentary

Sedimentary Rock• Sedimentary rocks form when

sediments are pressed together and harden.

• Sediments are bits of rock, soil, and once-living things.

• Example: Sandstone

Sedimentary Rock• Limestone is made of shells and skeletons of

ocean animals.

• Shale is the most common sedimentary rock. It is form from particles of clay.

Sedimentary Rock• Conglomerate forms from sediments of

different sizes

Metamorphic Rock

Metamorphic Rock• Metamorphic rocks are formed when

old rocks are changed into new rocks by heat and pressure.

• Igneous, Sedimentary, and Metamorphic rocks can all change into new rocks by heat and pressure.

• Ex.) Limestone changes to marble

Metamorphic Rock• Granite changes to Gneiss

Metamorphic Rock• Shale (SR) changes to slate (MR)…

that changes to schist (MR)