1. Rocks!

2. The Earth’s Crust
The whole earth is made of rocks & minerals. Inside the earth there is a liquid outer core of molten rock and on the outside there is a hard crust. If you compare the earth to an egg, the shell on an egg is like the crust on the earth. The crust is made up of rocks and minerals. Much of the crust is covered by water, sand, soil and ice. If you dig deep enough, you will always hit rocks

3. Rocks
All the rocks you see around you are made up of different minerals
Imagine a rock as a chocolate chip cookie, what does the cookie contain?
Flour, butter, sugar, chocolate chips
A rock contains different ingredients, they are called minerals. There are about 3000 minerals in the world.

4. 3 Types of Rocks There are 3 main types of rocks Igneous Sedimentary
Metamorphic

5. Igneous Rocks Igneous means made from fire or heat.
When volcanoes erupt and the liquid rock comes up to the earth's surface, then new igneous rock is made.

6. The texture of igneous rocks is very useful in identifying unknown rocks.
Igneous rocks with large crystals (crystals seen with the naked eye) are termed phaneritic and are intrusive.
Phaneritic: Slow cooling of magma or lava allows larger crystals to form.
Intrusive: The cooling of magma deep in the Earth

7. Igneous rocks with small crystals (crystals that cannot be seen with the nakedeye) are termed aphanitic and are extrusive.
aphanitic: Rapid cooling of magma or lava produces very small crystals or a glassy surface
extrusive: When magma reaches the Earth's surface in a volcano and cools quickly
Granite

8. Sedimentary Rocks
Are composed of particles derived from pre-existing rocks or by the crystallization of minerals that were held in solutions.
These rocks form in layers or strata.

9. Sedimentary Rocks 3 important factors:
1. Clastic- rocks containing particles from pre-existing rocks.
2. Organic- rock is made from shells or other fossil fragments.
3. Chemical- indicates the minerals were produced by chemical precipitation.
Think of the fragments of rock as pieces of paper, a few sheets of paper wouldn’t make any weight difference, but a big stack of yellow pages would soon weigh heavily. Eventually the weight of the rocks forms sedimentary rocks (over millions of years)

10. Metamorphic Rocks Metamorphic rocks are ones that have changed.
‘Meta’ and ‘morph’ both mean change in Greek
All metamorphic rocks would once have been igneous or sedimentary.
What do you think made them change?
Metamorphic rocks are rocks that have been altered and deformed physically and/or chemically by heat and pressure.

11. Metamorphic Rocks Have foliated or non-foliated textures.
Foliated- contain parallel planes of platy minerals.
Non-foliated-do not contain any parallel planes, but do exhibit alterations such as textural changes due to obliteration of mineral grains.

12. Rocks and their uses
Rocks are very useful, can you think what they are used for?
Fireplaces, roofs, worktops, tables, walls, sharpening knives, headstones, ornaments, pathways, jewellery, drawing, scrubbing feet!
What are the properties of rocks?
Do they all have the same properties?
Allow children to discuss their ideas with talking partner/table group. Introduce terms permeable/impermeable. Hard/soft, rough/smooth, can be scratched, can’t be scratched.

13. Beautiful Rocks!
People like to wear rocks as jewellery and decorate their homes with rocks.
Can you think of examples of these rocks?

15. Semi-precious stones

16. Other words for Rocks
We sometimes call rocks pebbles, boulders, stones, crystals or gemstones.
A boulder is a large rock
A pebble is a small rock that has been rounded by wind or water.
Stones are larger than pebbles.
Crystals and gemstones are rocks made of just one mineral. E.g a diamond is made of carbon.