Minerals and Energy Resources Test - 23

Karnataka is the largest producer and accounts for nearly one-fourth of the total iron ore produced in India. In Karnataka production of iron ore has increased by about three times since 1980.

Iron ores are widely distributed in the state, but high grade ore deposits are those of Kemmangundi in Bababudan hills of Chikmagalur district and Sandur and Hospet in Bellary district. Most of the ores are high grade haematite and magnetite. The other important producing districts are Chitradurga, Uttar Kannad, Shimoga, Dharwar and Tumkur.

Chhota Nagpur Palteau has formed in the Pre-Cambrian times and thus made of igneous rocks making it a storehouse of minerals. It is rich in minerals like coal, iron-ore, bauxite, mica, limestone, copper etc

• A mineral is a solid, naturally occurring combination of inorganic substances. Metallic minerals are minerals which contain one or more metallic elements.
  
• Metallic minerals occur in rare, naturally formed concentrations known as mineral deposits. These deposits can consist of a variety of metallic minerals containing valuable metals such as nickel (pentlandite), copper (chalcopyrite), zinc (sphalerite), lead (galena) and gold (occurs as a native element or as a minor constituent within other minerals) that are used in all aspects of our daily lives.
  
• Metallic minerals must be broken apart and chemically processed to extract the useful metal from the mineral.
  

Resources that are drawn from nature and used without much modification are called natural resources. The air we breathe, the water in our rivers and lakes, the soils, minerals are all natural resources. 

Energy minerals are used to produce electricity, fuel for transportation, heating for homes and offices and in the manufacture of plastics. Energy minerals include coal, oil, natural gas and uranium.

 Certain minerals may occur as alluvial deposits in sands of valley floors and the base of hills. These deposits are called ‘placer deposits’ and generally contain minerals, which are not corroded by water. Gold, silver, tin and platinum are most important among such minerals. 

Magnetite is a mineral and one of the main iron ores. With the chemical formula $$Fe_3O_4$$, it is one of the oxides of iron. It is the most magnetic of all the naturally-occurring minerals on Earth. Naturally-magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism. Today it is mined as iron ore.

The total recoverable reserves of iron ore in India are about 9,602 million tonnes of hematite and 3,408 million tonnes of magnetite. Chhattisgarh, Madhya Pradesh, Karnataka, Jharkhand, Odisha, Goa, Maharashtra, Andhra Pradesh, Kerala, Rajasthan and Tamil Nadu are the principal Indian producers of iron ore.