| A | B |
|---|
| mineral | An object that is solid, formed in nature, and never been alive. |
| rock | A solid made of minerals. |
| crust | A solid outside layer of the Earth. |
| mantle | The middle layer of the Earth. |
| core | The center of the Earth. |
| igneous rock | A rock that was once melted rock but has cooked and hardened. |
| sedimentary rock | A rock that has formed from material that has settled into layers and been squeezed until it hardens into rock. |
| metamorphic rock | A rock that has been changed by heat and pressure. |
| rock cycle | A process in which one type of rock changes into another type of rock. |
| fossil | Something that has lasted from a living thing that died long ago. |
