(i) Red sandstone.
(ii) Students should do this exercise yourself.
Hint: Example of Red sandstone: Silli (stone slab used in roofs of SPS rooms in the foot schools of Delhi).

(a) The Taj Mahal is made up of white marble.
(b) The Red Fort is made up of red sandstone.
(c) The Humayun tomb is made up of red sandstone.

Differences between crust and core are

Minerals are naturally occurring substances which have certain physical properties and definite chemical composition. Minerals are very important to humankind. Some are used as fuels. e.g. coal, natural gas and petroleum. They are also used in industries (iron, aluminium, gold, uranium, etc), in medicine, in fertilisers, etc

Rocks are very useful to us. The hard rocks are used for making roads, houses and buildings.

The three major types of rocks are igneous rocks, sedimentary rocks and metamorphic rocks

Crust, mantle and core are the three types of layers of the Earth.

(a) Crust.
(b) Silica and Magnesium (SiMa).
(c) Core is the innermost layer of the Earth

The earth is made up of several concentric layers with one inside another just like an onion. The basic features of the interior of the earth are
(i) Crust It is the uppermost layer over the earth's surface which is the thinnest of all the layers. It is about 35 km on the continental masses and only 5 km on the ocean floors. The continental mass are made up of silica and alumina. It is thus called SiAl (Si-Silica and AI-Alumina). The oceanic crust mainly consists of Silica and Magnesium; it is therefore called SiMa (Si-Silica and Ma-Magnesium.
(ii) Mantle It is just beneath the crust which extends up to a depth of 2900 km below the crust.
(iii) Core The innermost layer is the core with a radius of about 3500 km. It is mainly made up of Nickel and Iron and is called NiFe (Ni-Nickel and Fe-Ferrous i.e. iron). The central core has very high temperature and pressure.