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Non-metallic and atomic minerals, and coal

Mineral and energy resources of India · Part 2 / 3 · Fact-checked on 8 November 2026 · how we check

Written with AI from the sources listed at the bottom of this page, then fact-checked by a separate AI.

Mica, limestone, dolomite, gypsum and rock phosphate with their uses and areas; uranium and thorium and the three-stage nuclear programme; how coal forms and its grades; the Gondwana coalfields, Tertiary coal and lignite; the quality of Indian coal; and coal policy from nationalisation to commercial mining.

Part 1 dealt with the metallic minerals, valued for the metal locked inside them. This part turns first to minerals that industry uses largely as they come out of the ground: mica for electrical goods, limestone and dolomite for cement and steel, gypsum and rock phosphate for building materials and fertiliser. It then looks at the atomic minerals, uranium and thorium, which fuel India's nuclear programme. The longest section is on coal. Coal-fired power stations generate most of India's electricity, coal is baked into coke for steel, and the coalfields have shaped the industrial map of eastern and central India. Understanding where coal lies, why its quality varies and how its mining has been governed explains a great deal about India's energy choices, which Part 3 completes with petroleum, natural gas and electricity.

Mica is a mineral that splits into very thin, flexible, transparent sheets. It does not conduct electricity, withstands high temperatures and resists moisture, so it has long been used as an insulator in electrical and electronic equipment, as well as in paints and cosmetics. Muscovite, the light-coloured variety, is the chief commercial mica. India's main belts are the Koderma–Giridih–Hazaribagh area of Jharkhand, once known as the country's mica capital, the Nellore district of Andhra Pradesh, and the Bhilwara and Ajmer areas of Rajasthan. India was long the world's leading supplier of sheet mica, but demand for it fell as synthetic insulators replaced it in many uses, and much of the remaining output now comes from small, scattered workings. The mica story shows that a mineral's value depends on technology: a deposit prized in one era can lose its market in the next.

Limestone is a sedimentary rock made mostly of calcium carbonate, often built from the shells and skeletons of ancient sea creatures. It is the basic raw material of cement, which takes the greater part of the limestone mined in India; it is also used as a flux in blast furnaces, where it combines with impurities in iron ore to form slag, and in the chemical, glass and paper industries. Deposits are widespread across the Peninsula, with large ones in Rajasthan, Madhya Pradesh, Andhra Pradesh, Telangana, Karnataka, Chhattisgarh, Gujarat and Tamil Nadu. Because cement is heavy and cheap, cement plants are usually built close to limestone quarries. Dolomite, a carbonate of calcium and magnesium, is used for the same flux role in steel plants and in heat-resistant linings; Odisha, Chhattisgarh and Madhya Pradesh are major sources. When limestone is changed by heat and pressure it becomes marble, a metamorphic rock; the white marble of Makrana in Rajasthan, used in the Taj Mahal, is the best-known Indian example.

Two more non-metallic minerals matter for building and farming. Gypsum, a hydrated calcium sulphate, forms where salty water evaporates, which is why it is found mainly in the dry north-west; Rajasthan, especially Bikaner, Nagaur, Barmer and Jaisalmer, produces most of India's output. A little gypsum is mixed into cement to slow its setting; it is also used to make plaster of Paris and fertiliser, and spread on alkaline (usar) soils to reclaim them, a use met in the chapter on soils. Rock phosphate is the raw material for phosphatic fertilisers. India's main deposits are at Jhamarkotra near Udaipur in Rajasthan and in the Jhabua area of Madhya Pradesh, with smaller ones in Uttar Pradesh and Uttarakhand. Domestic output covers only part of the need, so India imports much of its rock phosphate and phosphoric acid, and almost all its potash. This dependence on imported fertiliser minerals makes food security sensitive to world prices.

Atomic minerals supply the fuel for nuclear power. Uranium is mined at Jaduguda in the East Singhbhum district of Jharkhand, India's first uranium mine, opened in 1967, and at Tummalapalle in the Kadapa district of Andhra Pradesh, a large but low-grade deposit; both are worked by the public-sector Uranium Corporation of India. India's uranium is limited and much of it is low-grade, but its thorium is abundant. Thorium occurs in monazite, a heavy mineral concentrated in the beach sands of Kerala (around Chavara), Tamil Nadu and Odisha, which also yields rare earth elements. This mismatch shaped the three-stage nuclear programme planned by Homi Bhabha: reactors burning natural uranium first, then fast breeder reactors using the plutonium they produce, and finally reactors running on thorium. Atomic minerals are explored by the Atomic Minerals Directorate for Exploration and Research, based in Hyderabad, and their mining is reserved for government agencies.

Coal is a rock made from plant remains. In ancient swamps, dead trees and plants piled up faster than they could rot, were buried under sediment, and over millions of years heat and pressure drove out water and gases and raised their carbon content. The longer and deeper this process, the higher the grade. Peat, the first stage, is soft and wet and burns with much smoke. lignite, or brown coal, has more carbon but still a lot of moisture. Bituminous coal, the most widely used grade, is harder and gives more heat; anthracite, the highest grade, is hard, shiny and burns with little smoke, but India has very little of it, mainly in Jammu and Kashmir. Use divides coal further. coking coal is bituminous coal that, when baked without air, fuses into coke, the fuel and reducing agent of blast furnaces; non-coking or thermal coal is burnt in power stations, cement kilns and brick kilns.

Nearly all of India's coal is Gondwana coal, formed mostly more than 250 million years ago and preserved in sunken troughs along the rivers of the Peninsula. The Damodar valley of Jharkhand and West Bengal is the historic heart of the industry. Commercial coal mining in India began at Raniganj in 1774, and Jharia holds the country's largest store of coking coal, which is why the steel plants of Jamshedpur, Bokaro, Durgapur and Burnpur grew up nearby; Bokaro, Giridih and Karanpura are other fields in the valley. Further west, the Son valley holds the Singrauli field on the Madhya Pradesh–Uttar Pradesh border, ringed by large power stations. The Mahanadi basin has Talcher and the Ib valley in Odisha and Korba in Chhattisgarh; the Godavari valley has the Singareni fields of Telangana; and the Wardha valley has the Chandrapur area of Maharashtra. According to the Geological Survey of India's coal inventory, Jharkhand, Odisha and Chhattisgarh together hold most of the country's coal resources.

A small share of India's coal is far younger. Tertiary coal, formed in the Tertiary period, is found in the north-east: the Makum field near Margherita and Ledo in Assam, the Garo, Khasi and Jaintia hills of Meghalaya, and parts of Arunachal Pradesh and Nagaland. It has less carbon than Gondwana coal and is high in sulphur, which makes it polluting and corrosive to burn. In Meghalaya, unscientific 'rat-hole' mining through narrow tunnels led the National Green Tribunal to ban that method in 2014. lignite, also mostly of Tertiary age, is the other low-grade coal. Tamil Nadu holds most of India's lignite, and the open-cast mines at Neyveli in Cuddalore district, run by NLC India, feed power stations on the spot. Gujarat (Kutch and Bharuch), Rajasthan (Barmer and the Palana area of Bikaner) and Jammu and Kashmir have smaller deposits. Because lignite is bulky and wet, it is usually burnt in power stations right beside the mine rather than transported far.

Indian coal is plentiful but not of high quality. Most Gondwana coal carries a large share of ash, the unburnable mineral matter left behind, which lowers its heat value, wears out boilers and leaves huge heaps of fly ash at power stations; on the other hand it is generally low in sulphur. The ash problem is most serious for steel. Domestic coking coal is limited and ash-rich even after washing, so India's steel plants import a large part of the coking coal they need, while thermal coal is also imported for some coastal power stations. Washeries, which remove some of the ash before the coal is dispatched, help but add cost. Coal also brings local costs: open-cast mines strip forests and farmland, mine fires have burnt underground at Jharia for over a century, and mining towns suffer dust and water pollution. These problems explain why coal is at once India's most important energy mineral and its most contested one.

Coal has also had a distinct policy history. After independence most mines were private, and many were worked wastefully and unsafely. The government first nationalised the coking-coal mines, under the Coking Coal Mines (Nationalisation) Act of 1972, and then the remaining coal mines under the Coal Mines (Nationalisation) Act of 1973. Coal India Limited was set up in 1975 to run them, and it remains the largest producer; Singareni Collieries in Telangana is the other major public-sector miner. Later, coal blocks were allotted to private and public companies for their own use, such as steel or power plants. In 2014, in Manohar Lal Sharma v. Principal Secretary, the Supreme Court held that the allotments made between 1993 and 2010 were arbitrary and cancelled almost all of them. The Coal Mines (Special Provisions) Act, 2015 then provided for re-allocating blocks by auction, and from 2020 private companies were allowed to mine coal for sale on the open market, ending the public sector's monopoly over commercial coal mining.

The minerals of this part follow the same geological logic as the metals of Part 1. Mica, limestone and dolomite come from the old rocks of the Peninsula, gypsum from the dry north-west, and thorium from the beach sands of the southern and eastern coasts. Coal lies mostly in the Gondwana troughs of the Damodar, Son, Mahanadi, Godavari and Wardha valleys, with younger, poorer coal and lignite in the north-east, Tamil Nadu, Gujarat and Rajasthan. Two dependencies stand out: India imports much of its coking coal and most of its fertiliser minerals, while its plentiful thorium waits on the last stage of the nuclear programme. Coal's story also shows how law shapes geography, from nationalisation in the 1970s to auctions and commercial mining after the 2014 judgment. Part 3 completes the picture with petroleum, natural gas and the generation of electricity.

Exam traps

• Jharia = India's largest store of COKING coal; Raniganj = the OLDEST coalfield (commercial mining from 1774). Do not swap them.
• Neyveli (Tamil Nadu) mines LIGNITE, not bituminous coal; Tamil Nadu holds most of India's lignite.
• Gondwana coal = nearly all of India's coal, older, in Peninsular river valleys, high ash but LOW sulphur; Tertiary coal = north-east, younger, HIGH sulphur.
• Carbon content rises in the order peat < lignite < bituminous < anthracite; anthracite is rare in India (Jammu and Kashmir).
• Thorium comes from MONAZITE in beach sands (Kerala, Tamil Nadu, Odisha); uranium is mined at Jaduguda (Jharkhand) and Tummalapalle (Andhra Pradesh).
• Coal mines were nationalised in 1971–73 and Coal India was formed in 1975, AFTER nationalisation, not before.
• Gypsum (mostly Rajasthan) is used to reclaim ALKALINE (usar) soils and to slow the setting of cement; lime, not gypsum, is used on acidic soils.
• Marble is METAMORPHOSED limestone (Makrana, Rajasthan); limestone itself is sedimentary.

Recap

• Mica: thin sheets, electrical insulator; Koderma–Giridih (Jharkhand), Nellore (Andhra Pradesh), Bhilwara–Ajmer (Rajasthan).
• Limestone: mainly for cement, also a flux in steel; dolomite also a flux; marble is metamorphosed limestone (Makrana).
• Gypsum: mostly Rajasthan; cement, plaster of Paris, alkaline-soil reclamation. Rock phosphate: Jhamarkotra, Jhabua; potash almost wholly imported.
• Uranium: Jaduguda (1967), Tummalapalle; thorium in monazite beach sands of Kerala, Tamil Nadu and Odisha; Bhabha's three-stage programme.
• Coal grades: peat, lignite, bituminous, anthracite; coking coal makes coke for blast furnaces; Indian coal is high in ash, low in sulphur.
• Gondwana coal (nearly all): Damodar (Raniganj 1774, Jharia coking coal, Bokaro), Singrauli, Talcher, Ib, Korba, Singareni, Chandrapur; Jharkhand, Odisha, Chhattisgarh hold most resources.
• Tertiary coal: north-east, high sulphur; rat-hole mining banned by the NGT (2014). Lignite: mostly Tamil Nadu (Neyveli), also Gujarat, Rajasthan.
• Policy: nationalisation 1972–73, Coal India 1975; 2014 judgment cancelled 1993–2010 allotments; Coal Mines (Special Provisions) Act 2015; commercial mining from 2020.

Practice questions

Sources

• Indian Bureau of Mines, Indian Minerals Yearbook: mica, limestone, dolomite, gypsum, rock phosphate and potash — https://ibm.gov.in
• Department of Atomic Energy and Atomic Minerals Directorate for Exploration and Research: uranium and thorium resources; the three-stage nuclear power programme — https://dae.gov.in
• Ministry of Coal: coal resources and coalfields, history of the coal sector, coal block auctions and commercial coal mining — https://coal.gov.in
• Geological Survey of India: national inventory of coal and lignite resources; Gondwana and Tertiary coal — https://www.gsi.gov.in
• Coking Coal Mines (Nationalisation) Act, 1972; Coal Mines (Nationalisation) Act, 1973; Coal Mines (Special Provisions) Act, 2015 — https://www.indiacode.nic.in
• Supreme Court of India: Manohar Lal Sharma v. Principal Secretary (2014), coal block allocation — https://www.sci.gov.in