Learning stageStage 4, Stage 5, Stage 6
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A rock is a combination of one (such as quartzite) or more (such as granite) mineral particles. These combine through either crystallisation of molten magma (igneous rocks), settling of particles (sedimentary rocks), or reheating and pressure applied to pre-existing rocks (metamorphic rocks), with no set chemical composition or atomic structure.
- Molten rock is called magma when it is inside the earth and lava when it is released from a volcano.
- Fossils are only found in sedimentary rocks.
- Some rocks like pumice can float on water.
- The oldest minerals in the world are found in Jack Hills in Western Australia. The mineral is called zircon and it is 4.374 billion years old!
- Name an example of a sedimentary rock and describe the way it formed.
- Where do igneous rocks form? Give an example of a felsic and a mafic igneous rock.
- What are the differences between a foliated and non-foliated metamorphic rock?
- Select a metamorphic rock and describe how it formed from its parent rock.
A series of three posters showing the main ways that sedimentary, igneous and metamorphic rocks are classified. They can be used to help identify rocks alongside a dichotomous key activity.