Rocks Vocabulary Words

1.) Igneous Rocks - Rocks that form when either magma or lava cools and hardens.

2.) Intrusive Igneous - Igneous rocks that form inside the Earth when magma cools slowly.

These rocks have larger crystals due to the slow cooling.

3.) Extrusive Igneous - Igneous rocks that form on the surface of the Earth from lava cooling

quickly. No visible crystals due to the rapid cooling.

4.) Lava – Molten (melted) minerals above the Earth's crust.

5.) Magma -Molten minerals below the Earth's crust.

6.) Sedimentary rocks - rocks that form when layers of sediments are squeezed together by

pressure. Usually form in layers and may contain fossils.

7.) Sediments - Mud, dirt, sea shells, small rocks, sand, dead plants and animals, etc that pile

up on the bottom of a body of water.

8.) Clastic sedimentary- Rocks that form when sediments are buried, compacted and cemented together by calcite or quartz

9.) Chemical sedimentary rock- Rocks that form when water evaporates

10.) Organic sedimentary rock- Rocks that form from remains or fossils of once living plants and animals

11.) Metamorphic Rock - Rocks made when existing rocks are placed under heat and pressure

DEEP inside the Earth. Heat is not enough to melt the rock but does cause chemical changes in rock.
12.) Foliated - Mineral grains that are arranged in planes or bands

13.) Non-foliated - Metamorphic rocks that do not have mineral grains that are aligned in planes or bands.

14.) Rock Cycle - The series of processes in which rock changes from one type to another