Maheswari

Rocks

Rocks are natural solid materials that make up the Earth’s crust. They are found everywhere on land, mountains, riverbeds, and even under the sea.

Rocks are made of one or more minerals. Some rocks are made from only one type of mineral, while others are made from many minerals mixed together.

There are different types of rocks:

• Igneous rocks (formed when hot molten lava cools and becomes solid)

• Sedimentary rocks (formed from layers of sediments like sand and mud)

• Metamorphic rocks (formed when existing rocks change due to heat and pressure)

Examples of rocks include granite, basalt, sandstone, and marble.

Minerals

Minerals are natural substances found in the Earth. They are not made by living things. Minerals are the building blocks of rocks.

Each mineral has its own physical properties such as:

• Colour

• Hardness

• Shine (lustre)

• Shape of crystals

Some common minerals are quartz, mica, and feldspar. These minerals combine in different ways to form different rocks.

For example, granite is made of quartz, mica, and feldspar.

Soil

Soil is the top layer of the Earth where plants grow. It is very important for life because it provides nutrients, water, and support for plants.

Soil is made from:

• Small rock particles (formed when rocks break down)

• Dead and decayed plants and animals

• Air

• Water

Soil is formed through a process called weathering. Weathering means breaking down of rocks into smaller pieces due to wind, water, heat, and other natural forces.

Soil has different layers:

• Topsoil (upper layer, rich in nutrients, where plants grow)

• Subsoil (below topsoil, has more minerals and less organic matter)

• Bedrock (solid rock layer underneath)

Fun fact

Sugar looks crystal-like, but it is not a mineral because it comes from living things.