Page 105 - SST Class 07

The properties of these rocks depend on the metamorphic rocks. A metal can be pressed into
materials they are made of. These materials are wires and sheets. Some important metals are iron,
called minerals. A rock may have one or more gold, silver, lead, copper, zinc etc.
minerals. Minerals are present in rocks naturally
Non-metallic Minerals
and can be identified with their physical
properties and chemical composition. We get These minerals are chiefly associated with
metals or chemicals from minerals. A mineral has sedimentary rocks, such as clay, sulphur, coal,
two or three simple substances called elements . petroleum, salt etc.
The rock which has a large amount of a mineral is The modern progress and development could not
called an ore . Such rocks are mined for procuring have been achieved without minerals, so
that mineral. important they are to us.

Minerals are of great economic value. Their
importance can be gauged from the fact that Activity
different ages in the history of man have been Name any four metals that are used in your
named after minerals : Iron Age, Copper Age, house :
Bronze Age.
(a) __________________________________
We can classify minerals into two broad (b) __________________________________
types—metallic and non-metallic .
(c) __________________________________
Metallic Minerals
(d) __________________________________
Metallic minerals are found in igneous and

v The earth is made up of three main layers—crust, mantle and core.
v The crust is the outermost covering and is made up of SIAL and SIMA.

v The core is the innermost layer of the earth.
v The inner core is solid while the outer core is in molten state.
v Rock is the material that forms the crust of the earth.
v Rocks are of three types—igneous, sedimentary and metamorphic.
v Rocks undergo a change, this process is called rock cycle.

v We get minerals from the rocks which are of great economical value.

A. Tick (3) the right option :

1. ______________ is the most important layer as it sustains life.
(a) core (b) crust (c) mantle
2. The oceanic crust is made up of ______________ .
(a) SIMA (b) SIAL (c) NIFE
3. The layer just below the crust is called ______________ .
(a) core (b) mantle (c) magma

Inside the Earth
105