USES OF MINERALS

Minerals can be used for:

• Construction materials. Gypsum is used to make cement and plaster.
• Obtaining metals. Iron is extracted from magnetite. Copper is obtained from chalcopyrite.
• Making jewellery. Diamonds, rubies and emeralds are used to make jewellery.

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.

THE PROPERTIES OF MINERALS

Every mineral is different from all other minerals.
You can identify a mineral by its properties:

• Hardness: a mineral is hard when it is difficult to scratch.
• Lustre: lustre means the way a mineral reflects light. Some minerals are very shiny. Others are not shiny.
• Colour: some minerals are always the same colour. Others can be different colours.
• Shape: Some minerals have a regular shape. Others have an irregular shape.

WHAT ARE MINERALS?

Minerals are natural, solid substances.
All minerals are made up of only one substance.
They can be found as parts of rocks or in their pure state.
Graphite: It is a natural substance.
It is a mineral.
It is soft and when we press it, layers slide off and leave marks on the paper.

Graphite.

We use graphite when we write with a pencil.

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).

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)