Page 149 - SST Class 08
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Minerals and Power
Resources
Minerals are naturally occurring substances. They history of human civilization. Therefore, various
have a definite chemical composition. Minerals stages of human development have been named
are formed in different types of geological envi- after minerals, such as :
ronments, under varying conditions. You can g The Stone Age marked the time when
identify and classify minerals on the basis of their humans made weapons and implements
physical properties such as colour, density, from stones.
hardness. You can also identify them on the g Copper as probably the first metal that
basis of their chemical properties like solubility. humans learnt to mine and with its use
began the Copper Age.
g In the Bronze Age humans developed a
stronger and more durable metal by mixing
copper and tin.
g About 3,000 years ago, the Bronze Age was
replaced by the Iron Age.
g Even the Iron Age has been replaced by the
Steel Age in modern times.
The search for precious minerals took humans to
the remotest part of the earth. What charmed
Minerals
him most was perhaps their luster or shine.
Minerals are non-living solid substances which
During the last 200 years, great progress has
are concentrated in a particular area or rock
been made in the discovery, extraction and
formations. A mineral may or may not be com-
utilisation of mineral resources.
mercially useful. We know that iron is found in
TYPES OF MINERALS
most rocks, but it is mined only in those regions
where it occurs as ores. Minerals have the follow- There are over three thousand different minerals.
ing characteristics : On the basis of composition, minerals are classi-
fied mainly as metallic and non-metallic minerals.
g They are unevenly distributed over the
earth’s surface. Minerals
g They are mixed up with a large variety of
impurities. Metallic Non-metallic
g The mineral resources are exhaustible.
The mineral resources of the earth have been Ferrous Non-ferrous
exploited and used since pre-historic times. Metallic Minerals
Minerals have played an important role in the
The metallic minerals contain metal in raw form.
Social Science-8 149
