Question

Which mineral is found in Monazite sand?
A. Oil
B. Uranium
C. Thorium
D. Coal

Answer 1

Hint:
Minerals are defined as the substances that are formed naturally in the Earth.
The mineral found in the monazite sand is a radioactive chemical element.
It is three times more abundant than uranium in Earth’s crust.

Complete answer:
Monazite is three different minerals technically, but due to a lack of major differences between them, they are referred to as one mineral, monazite. It is reddish-brown in colour.
Monazite is a rare phosphate mineral usually found in small isolated grains, as an additional mineral in igneous and metamorphic rocks. These grains are resistant to weathering and become accumulated in soils and sediments down from the host rock.

Monazite is a major source for thorium, lanthanum, and cerium. All these metals have various industrial uses and are considered quite precious.

It is estimated that thorium is about three to four times more abundant than uranium in the Earth’s crust, and is mainly refined from monazite sands (Monazite contains 2.5% thorium). Thorium is a highly radioactive metal and is predicted to be able to replace uranium in nuclear power generation. Therefore monazite is an extremely important ore mineral.
In India, monazite sand occurs on east and west coasts and in some places in Bihar. But the largest concentration is found on the coast of Kerala.

Option (A) Oil: It is an incorrect option. Oil is not a mineral but one of the three fossil fuels, the other two being Natural Gas and Coal.

Option (B) Uranium: It is an incorrect option. Uranium is estimated to be about three to four times less abundant than thorium in the Earth’s crust which is chiefly refined from monazite sands.

Option (D) Coal: Again, an incorrect option, as coal is not a mineral but a fossil fuel.

Therefore the correct answer is C

Note
Students often get confused between the difference between an ore and a mineral.
> Minerals are the naturally occurring substances found in the earth’s crust while Ores are usually used to extract metals economically.
> A large number of metals are present in the ores. All ores are minerals but all minerals are not certainly ores.