Minerals and Energy Resources Test - 1

Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters. Limestone is used as a raw material in cement industry. It is the main ingredient for the production of cement. About 1.5 tonnes of limestone is used in the manufacture of 1 tonne of cement. Mica is made up of a series of plates or leaves. It splits easily into thin sheets.

Mica is one of the most indispensable minerals used in electric and electronic industries, due to its di-electric strength, low power factor, insulating properties and resistance to high voltage. Mica is stable when exposed to electricity and extreme temperatures. It is used as an insulator in countless everyday electronic and electrical products -- including radio and TV sets, fans, microwaves, toasters, kettles and rice cookers -- as well as in heating systems.

Sedimentary minerals are formed as a result of deposition, accumulation and concentration in horizontal strata. Coal and some forms of iron ore have been concentrated as a result of long periods under great heat and pressure. Coal is a sedimentary mineral as it undergoes physical and chemical changes as a result of increased heat.
Gypsum is a mineral found in crystal as well as masses called gypsum rock. Massive gypsum rock forms within layers of sedimentary rock, typically found in thick beds or layers.
Halite is mainly a sedimentary mineral that usually forms in arid climates where ocean water evaporates. However, many inland lakes such as the Great Salt Lake of North America and the Dead Sea between Jordan and Israel are also the locations where halite forms now.

Odisha is the largest producer and produces over 37 per cent manganese ore of India. It is obtained from Gondite deposits in Sundargarh district and Kodurite and Khondolite deposits in Kalahandi and Koraput Districts. Manganese is also mined from the lateritic deposits in Bolangir and Sambalpur districts.

Mica is from the phyllosilicate mineral family, powdered white mica is used in a number of cosmetics, including toothpaste, for its sparkle. It is also used as a mild abrasive to aid in polishing of the tooth surface.

Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Bauxite is formed by lateritic weathering and residual accumulation of intercalated clay layers – dispersed clays which are concentrated as the enclosing limestones gradually dissolved during chemical weathering.The lateritic bauxite is found mostly in the countries of the tropics. It is formed by lateritization of various silicate rocks such as granite, gneiss, basalt, syenite, and shale. In comparison with the iron-rich laterites, the formation of bauxite depends even more on intense weathering conditions in a location with very good drainage. Bauxite is primarily comprised of aluminium oxide compounds (alumina), silica, iron oxides and titanium dioxide.

Mica is a mineral made up of a series of plates or leaves. It splits easily into thin sheets. These sheets can be so thin that a thousand can be layered into a mica sheet of a few centimeters high. Mica deposits are found in the northern edge of the Chota Nagpur plateau. Koderma Gaya – Hazaribagh belt of Jharkhand is the leading producer. In Rajasthan, the major mica producing area is around Ajmer. Nellore mica belt of Andhra Pradesh is also an important producer in the country. Mica is an important electrical insulating material with the added advantage of high resistance to higher temperatures. Besides, it is transparent, flexible, tough, fire proof and chemically stable.

Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO3). It often has variable amounts of silica in it, as well as varying amounts of clay, silt, and sand. Limestone rocks fall under the category of sedimentary rocks that are made from mineral calcite. This rock is used to make concrete and is an excellent building stone for humid regions. Various metals are extracted from the minerals after proper refinement. The mining process involves the excavation of large amounts of waste rock to remove the desired mineral ore. The ore is then crushed into finely ground tailings for chemical processing and separation to extract the target minerals. About 200 minerals are abundantly found in most of the rocks.

Magnetite is the finest iron ore with a very high content of iron up to 70 per cent. It has excellent magnetic qualities, especially valuable in the electrical industry. Hematite ore is the most important industrial iron ore in terms of the quantity used, but has a slightly lower iron content than magnetite. Magnetite is a rock mineral and one of the main iron ores, with the chemical formula Fe3O4. It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. It is the most magnetic of all the naturally-occurring minerals on Earth.

Ferrous metals account for maximum value, almost three-fourths, of the total production of metallic minerals. Ferrous minerals such as iron ore, manganese, chromite, etc. provide a strong base for the development of metallurgical industries. India is well-placed in respect of ferrous minerals both in reserves and production. India exports substantial quantities of ferrous minerals after meeting her internal demands.

Minerals occur in beds or layers in sedimentary rocks. They are formed as a result of deposition, accumulation, and concentration in the horizontal strata. For example - coal, which has been formed as a result of long periods under great heat and pressure. Minerals like gypsum, potash salt, and sodium salt are formed as a result of evaporation.

Krishna Godavari Basin is a peri-cratonic passive margin basin in India. It is spread across more than 50,000 square kilometres in the Krishna River and Godavari River basins in Andhra Pradesh. The site is known for the D-6 block where Reliance Industries discovered the biggest natural gas reserves in India in 2003. According to the Indian Directorate General of Hydrocarbons, the Andaman and Nicobar Islands in the Bay of Bengal are sitting of a vast unexplored natural gas reserves, estimated at around 610 million tons. Bombay High (now Mumbai High) field is an offshore oilfield located in the Arabian Sea, approximately 160 km west of the Mumbai coast, India. Discovered in 1974, the field commenced production in 1976 and is operated by the Oil and Natural Gas Corporation (ONGC).

About 80% of the manganese production in India comes from Balaghat District. The recently discovered copper deposit at Malanjkhand is regarded as the largest in the country. Bauxite, Kyanite, Marble, Dolomite, Clay and limestone are the other main minerals of the district. Singhbhum is famous for iron and copper. The Singhbhum district has been divided into three smaller districts, being East Singhbhum, West Singhbhum and Saraikela Kharsawan. These three districts are part of Jharkhand state. East Singhbhum is famous for Copper and Uranium mines. Panchpatmali deposits in Koraput district of Orissa are the most important bauxite deposits in the state, and Nellore belt in Andhra Pradesh is rich in mica deposits.

Most of the minerals in India are nationalised and their extraction is possible only after obtaining due permission from the government. But in most of the tribal areas of the north-east India, minerals are owned by individuals or communities. Coal mining in Jowai and Cherapunjee is done by family members in the form of a long narrow tunnel, known as 'rat hole' mining. Only minerals found in the tribal areas of northeast are owned by individuals or communities.

Uranium is found in Singhbhum and Hazaribagh districts of Jharkhand, and Gaya district of Bihar, and in sedimentary rocks of Saharanpur district of Uttar Pradesh. The largest source of uranium comprises the monazite sands, both beach and alluvial. Monazite sand rich in uranium is found in Kerala. Thorium is produced in Kerala, Jharkhand, Bihar, Tamil Nadu, and Rajasthan. In addition to uranium and thorium, beryllium and lithium are also the atomic minerals found mainly in Jharkhand, Madhya Pradesh, and Rajasthan.