| A | B |
|---|
| cleavage | tendency of minerals to break along smooth surfaces |
| fossil | the preserved remains of an ancient organism |
| hardness | the ability of a mineral to resist being scratched |
| igneous | rock formed from magma when it cools at earth's surface |
| lava | magma that reaches earth's surface |
| luster | the way light reflects from a rock's surface |
| metamorphic rock | changes in form as a result of heat, and pressure |
| mineral | natural, nonliving substances that make up rocks |
| ore | rock that is mined because it contains useful mineral |
| rock cycle | continuous changing of rocks from one kind to another |
| rock | hard substance formed from minerals |
| sediment | particles of rock or organic matter carried and deposited by wind or water |
| sedimentary | formed by compacting and cementing of sediments at the earth's surface |
| streak | color of powder left behind by a mineral when scratched on surface |
| weathering | breaking down or rocks at the earth's surface |
| Mohs Hardness Scale | shows the hardness of a few common minerals |
| magma | layer of melted rock below the Earth's crust |
| pressure | a build up of force that pushes on something |
| geologist | study Earth's history by examining rocks |
