Rocks! (1)

Rocks!Rocks!

The Earth’s CrustThe Earth’s Crust

RocksRocks

All the rocks you see around you are All the rocks you see around you are made up of different mineralsmade up of different minerals

Imagine a rock is a chocolate chip Imagine a rock is a chocolate chip cookie, what does the cookie contain?cookie, what does the cookie contain?

Flour, butter, sugar, chocolate chipsFlour, butter, sugar, chocolate chips A rock contains different ingredients, A rock contains different ingredients,

they are called minerals. There are they are called minerals. There are about 3000 minerals in the world.about 3000 minerals in the world.

3 Types of Rocks3 Types of Rocks

There are 3 main types of rocksThere are 3 main types of rocks IgneousIgneous SedimentarySedimentary MetamorphicMetamorphic

Igneous Rocks Igneous Rocks Igneous means made from fire or Igneous means made from fire or

heat. heat.

When volcanoes erupt and the liquid When volcanoes erupt and the liquid rock comes up to the earth's surface, rock comes up to the earth's surface, then new igneous rock is made. then new igneous rock is made.

When the rock is liquid & inside the When the rock is liquid & inside the earth, it is called magma. earth, it is called magma.

When the magma gets hard inside the When the magma gets hard inside the crust, it turns into granite. crust, it turns into granite.

Most mountains are made of granite. Most mountains are made of granite. It cools very slowly and is very hardIt cools very slowly and is very hard. .

Granite

Diorite

Sedimentary RocksSedimentary Rocks

Mountains are made of rockMountains are made of rock Weather can make the mountain Weather can make the mountain

rock crumblerock crumble These little bits of rock fall into rivers These little bits of rock fall into rivers

and streams and rest on the riverbedand streams and rest on the riverbed

Sedimentary RocksSedimentary Rocks

Sandstone

Shale

Sedimentary RocksSedimentary Rocks

Limestone is a type Limestone is a type of sedimentary of sedimentary rockrock

The Egyptian The Egyptian pyramids were pyramids were made using made using limestone.limestone.

Metamorphic RocksMetamorphic Rocks

Metamorphic rocks are ones that have Metamorphic rocks are ones that have changed. changed.

‘‘Meta’ and ‘morph’ both mean change Meta’ and ‘morph’ both mean change in Greekin Greek

All metamorphic rocks would once All metamorphic rocks would once have been igneous or sedimentary.have been igneous or sedimentary.

What do you think made them What do you think made them change?change?

Metamorphic RocksMetamorphic Rocks

Metamorphic RocksMetamorphic Rocks

Squeeze your hands together as Squeeze your hands together as tightly as you can.tightly as you can.

What do you notice?What do you notice? Your hands will start to get warm and Your hands will start to get warm and

you will feel pressure. This is a bit you will feel pressure. This is a bit like the Earth’s crust pressing its like the Earth’s crust pressing its rocks. The heat and pressure rocks. The heat and pressure changes them into a different type of changes them into a different type of rock.rock.

Limestone metamorphoses into marble

Slate is another metamorphic rock, formed from shale. It is used to roof houses because it forms in thin layers.

Rocks and their usesRocks and their uses

Rocks are very useful, can you think Rocks are very useful, can you think what they are used for?what they are used for?

Fireplaces, roofs, worktops, tables, Fireplaces, roofs, worktops, tables, walls, sharpening knives, headstones, walls, sharpening knives, headstones, ornaments, pathways, jewellery, ornaments, pathways, jewellery, drawing, scrubbing feet!drawing, scrubbing feet!

What are the properties of rocks? What are the properties of rocks? Do they all have the same properties?Do they all have the same properties?

Beautiful Rocks!Beautiful Rocks!

People like to wear rocks as jewellery People like to wear rocks as jewellery and decorate their homes with rocks. and decorate their homes with rocks.

Can you think of examples of these Can you think of examples of these rocks?rocks?

Semi-precious stonesSemi-precious stones

Other words for RocksOther words for Rocks

We sometimes call rocks pebbles, We sometimes call rocks pebbles, boulders, stones, crystals or gemstones.boulders, stones, crystals or gemstones.

A boulder is a large rockA boulder is a large rock A pebble is a small rock that has been A pebble is a small rock that has been

rounded by wind or water.rounded by wind or water. Stones are larger than pebbles.Stones are larger than pebbles. Crystals and gemstones are rocks made of Crystals and gemstones are rocks made of

just one mineral. E.g a diamond is made of just one mineral. E.g a diamond is made of carbon.carbon.