Rocks and Minerals Class 2 Notes Science

Rocks

The earth is made up of different kinds of rocks. Some are big while some are small. Rocks can be seen at many places like the hills, mountains, valleys and under the sea.

Sometimes, rocks break into smaller pieces called stones. You must have seen stones of different types. Some are big, some are small and some are tiny. Some may be smooth while some may be rough. Some stones shine when they are polished.

Do you know
The small, rounded and smooth stones found near a river are called pebbles. They become round and smooth by the action of water.

Rocks are of different types. Some are hard while some are soft. For example, granite, marble and sandstone are hard rocks. Coal, chalk and slate are soft rocks.
Hard rocks

Soft rocks

Uses of Rocks

Granite is crushed and used to make roads. Large slabs of granite are used to make floors in the offices, hotels and houses. 

Marble can be smoothened by polishing. It is used to make beautiful statues. It is also used to build floors of the houses. The Taj Mahal, one of the seven wonders of the world, is built entirely of white marble. Marble is also found in other colours like black, grey, pink and green.
A statue made of marble

Do you know
Mount Rushmore in the United States is an amazing sight, with the faces of four presidents carved into a giant rock mountain.

Sandstone is used for making buildings. The Red Fort at Delhi is built of sandstone. 

The Red Fort

Coal, like many other useful rocks, is dug out from deep inside the earth. It is a soft rock. It is used as a fuel.

Coal as a Fuel

Chalk, a soft and white or grey variety of limestone rock, is used in the classrooms to write on the blackboards.

Slate of grey colour has been used to make slates and blackboards since a long time. It is also used to make the roofs of some houses.
Chalk and slate

Minerals

Rocks are made of minerals. A mineral is a substance that is formed naturally in the ground. The most common minerals that make up the rocks are mica and quartz. Another mineral is talc. It is the softest mineral and is used to make talcum powder. The lead used in your pencil is made from a soft mineral called graphite.
Graphite

You must have seen pieces of jewellery where gemstones are used. These gemstones are minerals too. They have to be cut into special shapes and polished. Some of these are the red ruby, green emerald and colourless diamond.
Gemstones

Do you know
The diamond is the hardest substance found on the earth.