MINERALS

Minerals are naturally occurring substances that have a definite chemical composition. These are available in different concentrations in different parts of the Earth. Some may be available on the land's surface, deep inside the cover, or under ocean beds. They are found mixed with other materials or impurities, and therefore they need to be processed to make them usable. Minerals can be identified based on their physical properties like color, hardness, density, solubility, and chemical properties.

Types of Minerals

There are about three thousand different minerals found on the Earth. They are broadly classified as metallic and non-metallic.

Metallic Minerals

As the name suggests, these minerals have metals in raw form. They are generally found in igneous and metamorphic rocks. These metals are good conductors of electricity. They are malleable, tensile, have luster or shine, and are ductile. Example: Copper, zinc, iron, gold, silver, lead, etc. Classification of Metallic MineralsThe metallic minerals are further sub-classified as ferrous and non-ferrous. Ferrous: These include those minerals which have iron content.

Example: Iron, manganese, and chromite.

Non-Ferrous: These minerals do not have iron but would have other metals.

Example: Gold, silver, lead, etc.

Non-Metallic

These are minerals that do not contain metals. They are found in sedimentary rocks and are nonmalleable, non-ductile, and do not have luster—for example, Mica, gypsum, coal, petroleum, etc.

Ore

Any naturally occurring mineral or aggregate of minerals from which economically important constituents, especially metals, can be extracted.

Rock

It is a naturally occurring solid aggregate of minerals. The Earth's outer solid layer, the lithosphere, is made of rock.

Extraction of Minerals

As stated earlier, minerals are found in various concentrations and at various locations in different forms and purities. They have to be extracted (taken out) and processed to make them usable. Various methods of extraction employed for this purpose are given below.

Mining

Extracting minerals from various depths below the surface of the Earth and the rocks are called mining. These are of two types:

Open Cast Mining: Minerals that are extracted by removing the top surface is called open-cast mining. This process is effective only when the minerals are not very deep down from the earth's surface.

Shaft Mining: When mineral deposits are extracted from deep down the Earth's surface by digging deep bores called shafts, it is known as shaft mining.

Drilling

The extraction process, which involves drilling into the Earth's surface with giant machines, is called mining. This process is commonly used for extracting petroleum and natural gas.

Quarrying

Minerals that lie on or near the surface of the Earth and are dugout. This process is called quarrying. This process is usually used to extract marbles, granites, etc.

Distribution of Minerals in the World

Asia

Asia has enormous reserves of coal, amounting to nearly 3/5th of the world's total. India, China, and Siberia have significant deposits. Petroleum deposits are also found in Asia. It accounts for almost 2/3rd of the world's reserves. India and China have considerable iron ore deposits. Asia has large deposits of bauxite, lead, and zinc. Asia produces more than half of the world's tin. Non-metallic minerals like asbestos, mica, and rock salt are also available in abundance in Asia.