MINERALS IN ROCKS

Rocks in the Earth's crust are made up of minerals.
Here are some:

• Quartz: Quartz is very hard. It can scratch glass. It is translucent. It can be white, pink or grey. It is found in granite.

• Feldspar: Feldspar is hard. It is not shiny. It can be different colours: white, green or brown. It is found in granite and clay.

• Calcite: Calcite is soft. It can be scratched with a knife. It can be white, orange or yellow. It is found in marble and limestone.

USES OF ROCKS

Rocks are used for many different things:

• Obtaining energy. Petroleum provides fuels, such as petrol and diesel.
• Making construction materials. Bricks and tiles are made from clay. Marble, granite and slate are also used in construction.
• Industrial uses. Factories make plastics, paints and fertilisers from petroleum.

WHAT ARE ROCKS LIKE?

All rocks are made up of minerals, but there are many different types:

• Some rocks are formed by just one mineral. Marble is made entirely of calcite.
• Other rocks are made up of several minerals. Granite is made up of quartz, feldspar and mica.
• Some rocks, such as limestone, sometimes have shells and sea creatures in them.
• Some rocks are hard (marble). Others are soft (clay). Others are liquid (petroleum).

WHAT ARE ROCKS?

Rocks form the solid part of the Earth.
They are found everywhere in nature.
Some rocks are dark (basalt).
Others are light in colour (limestone).
Some rocks are formed by large grains (granite).
Others are formed by fine grains (clay).

Rocks in nature (from wikipedia)

Clay: fine grains (from wikipedia)

Limestone: light in colour (from wikipedia)

Granite: large grains (from wikipedia)

Basalt: dark colour (from wikipedia)

REMEMBER

ROCKS AND MINERALS

Rocks and minerals have many uses.
For example, pencils are made up of a mineral called graphite.
Roof tiles are made of a rock called clay.

Pencil (photo by Saurabh R. Patil (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons) 

Graphite (photo by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons)

Roof tiles (photo by Procsilas Moscas (Flickr) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons)

Clay mineral (photo from Wikipedia)

SOIL

Soil is the top layer of the Earth's surface.
This is where plants grow.
Some animals, such as rabbits and worms, make their homes in soil.

Soil (photo from Wikipedia)