Question | Answer |
Rocks | Made of minerals.
Usually identified by how they look.
3 main types:
-igneous
-sedimentary
-metamorphic |
Igneous Rocks | Melted rocks, that cool and crystallize
Formed inside or above earth |
Sedimentary Rocks | Made when loose rocks become stuck together
Happens by compaction and cementation |
Metamorphic Rocks | Made when Igneous and Sedimentary rocks deep inside earth, are heated and under pressure for a long period of time. |
Compaction | Sediments are pressed together for a long period of time |
Cementation | Water dissolves crystals, making a glue. Some rocks will stick together forming a new rock. |
Minerals | Elements and compounds that are made naturally
Made up of crystals |
6 ways to identify minerals | 1. Moh's hardness scale
2. Crystals
3. Luster
4. Colour
5. Streak
6. Cleavage/Fracture |
Moh's Hardness Scale | To test how hard the rock or mineral is, from softest to hardest. |
Crystal | Straight edges, flat sides, and regular angles. |
Luster | "Shininess"
How light reflects from it |
Streak | The color that is made when the mineral is scraped or crushed |
Cleavage | The way a mineral breaks apart. It breaks with straight, flat edges. |
Fracture | Another way a mineral breaks apart. It breaks with rough, jagged edges. |
Erosion | Movement of rocks and minerals from one place to another.
Usually caused by gravity, wind, and movement of water and ice.
3 types:
Chemical
Biological
Mechanical |
Chemical weathering | Rock is changed by chemical reactions
Rock is weakened by coming into contact with pollution (water, air or acids) |
Mechanical weathering | Wearing away and physical breakdown of rocks
Due to gravity causing rocks to fall and break, and/or water rubbing particles of rock away
Caused by wind, water, gravity, and temperature change |
Biological weathering | Rock is changed by plants or animals living in or on it. |