Major Minerals — Set 6

Correct Answer: C. Thorium

• **Thorium** = the radioactive element extracted from monazite sands on Kerala's coast, key for India's 3-stage nuclear power program. • **India's thorium reserves** — India has the world's largest known thorium reserves (~25% of global reserves), primarily in coastal monazite sands of Kerala and Tamil Nadu. • 💡 Wrong-option analysis: Uranium: found at Jaduguda (Jharkhand) and Tummalapalle (AP), not primarily in monazite sands; Radium: not commercially extracted from monazite in India; Polonium: not a commercially significant mineral in India.

Correct Answer: D. Tamil Nadu

• **Tamil Nadu** = the leading producer of magnesite in India, with major deposits in the Salem region. • **Salem magnesite** — Salem district in Tamil Nadu has significant magnesite deposits used for refractory bricks in steel furnaces and chemical industries. • 💡 Wrong-option analysis: Karnataka: has some mineral deposits but not the leading magnesite producer; Uttarakhand: has limestone and some minerals but not leading in magnesite; Rajasthan: is a mineral-rich state but not the leading magnesite producer.

Correct Answer: B. Jharkhand

• **Jharkhand** = the location of Jharia coalfield in Dhanbad district, India's most important source of high-grade coking coal. • **Underground coal fires** — Jharia is also infamous for its long-standing underground coal fires that have been burning for over a century, threatening communities. • 💡 Wrong-option analysis: West Bengal: has Raniganj coalfield, India's oldest, but Jharia coking coal is in Jharkhand; Odisha: has Talcher coalfield, thermal coal not coking coal; Chhattisgarh: has Korba coalfield but not Jharia.

Correct Answer: B. Manganese

• **Manganese** = the essential alloying element that provides hardness and strength to steel by removing impurities like oxygen and sulfur. • **10 kg per tonne of steel** — approximately 10 kg of manganese ore is required to produce one tonne of steel, making it a critical industrial mineral. • 💡 Wrong-option analysis: Copper: used in electrical wiring, not for adding hardness to steel; Zinc: used for galvanizing steel (coating) but not as a hardening alloying element; Mica: electrical insulator, never used in steel manufacturing.

Correct Answer: A. Mumbai

• **Mumbai** = the major city south of which the Bassein offshore gas and oil field is located, in the Arabian Sea. • **Arabian Sea gas field** — Bassein is one of India's largest natural gas fields, operated by ONGC south of Mumbai; it helps meet India's growing natural gas demand. • 💡 Wrong-option analysis: Chennai: on the eastern coast; Bassein is in the Arabian Sea (western coast); Kochi: Bassein is not south of Kochi but south of Mumbai; Kolkata: on the eastern coast, not near Bassein.

Correct Answer: C. Iron Ore

• **Iron Ore** = the primary mineral of Singhbhum district in Jharkhand, forming the backbone of the Iron Ore Series of the Chota Nagpur plateau. • **Jamshedpur steel belt** — Singhbhum's iron ore supports major steel plants in Jamshedpur and surroundings; while Singhbhum also has copper deposits, iron ore is its most economically significant mineral. • 💡 Wrong-option analysis: Coal: major coal is in Dhanbad (Jharia), not Singhbhum; Copper: Singhbhum does have copper (Mosaboni mines) but iron ore is more dominant and economically significant; Bauxite: Singhbhum is not primarily known for bauxite.

Correct Answer: B. Talc

• **Talc** = the softest known mineral (score 1 on Mohs scale), widely used in cosmetics as talcum powder. • **Mohs scale score 1** — talc is the softest mineral on the Mohs hardness scale, used in talcum powder, paper manufacturing, and as a lubricant. • 💡 Wrong-option analysis: Diamond: hardest mineral (score 10 on Mohs scale), used in cutting tools and jewelry; Feldspar: moderately hard mineral (score 6), used in ceramics and glass; Quartz: hard mineral (score 7), used in glass, abrasives, and electronics.

Correct Answer: A. Karnataka

• **Karnataka** = the state where Hutti Gold Mines are located in Raichur district, currently India's only operational gold mine. • **India's only active gold mine** — Hutti Gold Mines in Karnataka's Raichur district are India's only operational gold mine after Kolar Gold Fields largely closed. • 💡 Wrong-option analysis: Kerala: no significant gold mining; Tamil Nadu: no active gold mines; Andhra Pradesh: has Ramagiri gold deposits but Hutti is in Karnataka.

Correct Answer: B. Rajasthan

• **Rajasthan** = the state with the largest estimated reserves of copper ore in India, in the Khetri-Singhana belt. • **Reserves vs. production** — while Madhya Pradesh (Malanjkhand) is the leading producer, Rajasthan holds the largest reserves; the Khetri-Singhana belt is India's most prominent copper-bearing region. • 💡 Wrong-option analysis: Madhya Pradesh: leading producer (Malanjkhand) but not the largest reserves holder; Odisha: has iron ore and bauxite as primary minerals, not largest copper reserves; Jharkhand: has Singhbhum copper deposits but smaller reserves than Rajasthan.

Correct Answer: B. Makum

• **Makum** = a Tertiary coalfield in Assam, meaning it is geologically younger than the Gondwana coalfields of central and eastern India. • **Tertiary coal characteristics** — Tertiary coal in Assam and Meghalaya is younger in age and generally has higher sulfur content than the superior Gondwana coal. • 💡 Wrong-option analysis: Jharia: located in Jharkhand, a Gondwana coalfield (Paleozoic era), not Tertiary; Raniganj: located in West Bengal, India's oldest Gondwana coalfield; Bokaro: Gondwana coalfield in Jharkhand, not Tertiary.