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The crust varies in thickness. It is 35-70 km thick in the and minerals. Metals are found in minerals present in
continents and 5-10 km thick in the ocean beds. the rocks which form the Earth's crust.

Rocks
The Earth’s crust is made up of naturally occurring
solid masses of minerals called rocks.
Rocks have unique characteristics based on the
minerals they are made up of, their chemical
composition and the manner in which they are

Core formed.
Mantle 3.500 Crust
2,900 km 5-70 km
Minerals
Minerals are inorganic substances which contain one
or more elements having specific physical and
chemical properties. The study of minerals is known as
mineralogy. Quartz, feldspar, mica, etc. are some of
the common rock forming minerals.

Classification of Rocks
Interior of the Earth
Rocks may be divided into three major categories
depending on how they were formed.
Mantle
Igneous Rocks
Below the crust lies the mantle which forms a major
part of the Earth's interior. It is about 2,900 km thick, Igneous rocks are also called primary or parent rocks
and is divided into the upper and lower mantle. This because they are the first kind of rocks to be formed.
layer is in a molten state and is made up of denser They are hard, crystalline rocks that solidify out of
materials. Most of the internal heat of the Earth is molten magma. These rocks may be grouped into two
circulated in this region. categories: intrusive and extrusive.

Core
AI Fact
The core is placed deep inside the mantle and has a Technology Literacy
liquid outer layer and a solid inner layer. AI has the capability of mapping of geographic locations
from multiple inputs and helps in prospecting for
The outer core is mainly composed of a nickel-iron
minerals, such as industrial raw materials, gemstones,
alloy and the inner core is almost entirely made up of or fertilizer minerals. Geologists also utilise machine
iron. Geologists believe that the Earth's magnetic field learning algorithms to discover ores.
is controlled by the outer core which is in liquid state.
Temperature increases with depth beneath the Intrusive Rocks
Earth's surface at the rate of 25-30 °C/km. At very Intrusive rocks are formed from
great depths, temperatures are extremely high. molten magma that cools and
solidifies inside the crust of the
Wow Fact Earth. They have coarse grains

The outer core is about 2,300 km thick while and large mineral crystals, for
the inner core is about 1,200 km in thickness. example granite.
Granite
Extrusive Rocks
They are formed when molten lava, which comes out
Earth’s Crust : Rocks and Minerals of volcanoes, cools on the surface of the Earth and

The Earth’s crust comprises numerous types of rocks solidifies. They have fine grains and small mineral
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