| A | B |
|---|
| metamorphic rock | rock that has changed as a result of heat and pressure |
| igneous rock | rock that forms from cooled molten lava |
| sedimentary rock | rock that forms when layers of sediment particles harden |
| mineral | a natural, nonliving solid crystal that makes up rock |
| luster | a measure of the way the surface of a mineral reflects light |
| weathering | a natural process that breaks down rock into tiny pieces |
| erosion | the movement of material such as rock, soil, shells and dead plant and animal matter from one place to another |
| magma | the layer of rock below Earth's crust that is partly melted |
| lava | what magma is called when it reaches Earth's surface; this is what bursts out of a volcano |
| sediment | the eroded material that settles at the bottom of lakes, rivers and oceans |
| soil | forms from weathered rock and contains dead and decaying matter, as well as living things |
| rock cycle | the recycling of old rock into new rock |
| Mohs scale of Hardness | tells scientists how easily a mineral can be scratched |
| fossils | the remains of animal that hardens into rock |
| streak | the color left behind when a mineral is scratched |
