Minerals and Ores

Radium is primarily obtained from pitchblende (also known as uraninite), which is a uranium-rich ore. The Curies discovered radium by processing tons of pitchblende ore to isolate this radioactive element.

Bauxite (Al2O3·2H2O) is the principal ore of aluminium, containing about 50-60% alumina. Calamine is zinc ore, calcite is calcium carbonate, and galena is lead sulphide. Bauxite is the primary commercial source of aluminium.

ACC (Associated Cement Companies Limited) is India's leading cement manufacturer. The company has been a major player in the cement industry since its founding in 1936 and is now part of the Ambuja-ACC group under the Adani portfolio.

PSL is primarily a pipe manufacturing company for the oil and gas industry. They produce specialized pipes and coatings for infrastructure projects. The key distractor is 'Steel' - while pipes are often steel, their specific business is pipe manufacturing.

Baroque pearls are the correct term for pearls with irregular, asymmetrical shapes. The term 'baroque' in this context refers to non-spherical, uneven pearls that can still be lustrous and valuable. 'Eggplant pearls' is not a standard pearl classification term. 'Semi-pearls' is not a recognized gemological term for irregular pearls.

Pitchblende, also known as uraninite, is primarily an ore of uranium. However, pitchblende was historically significant as the source from which Marie Curie discovered radium in 1898. The ore contains trace amounts of radium as a decay product of uranium. Silicon, astatine, and plutonium are not correct associations with pitchblende.

Chalcanthite is a hydrated copper sulfate mineral (CuSO4·5H2O). Its name comes from Greek 'chalkos' (copper) and 'anthos' (flower). It forms bright blue crystals and is an important ore of copper. The color is distinctive due to the copper ions.

Niyamgiri hills in Odisha was the site of Vedanta's proposed bauxite mining project, which faced massive opposition from local tribal communities due to environmental and cultural concerns. The Supreme Court ultimately banned the mining in 2013, upholding the rights of the Dongria Kondh tribe. The other options are different hill ranges in India - Nilgiri in Tamil Nadu/Kerala, Aravali in Rajasthan, and Nandi in Karnataka.

Khetri in Rajasthan is famous for its copper mines and is one of India's largest copper mining centers. The Khetri Copper Complex is operated by Hindustan Copper Limited and has been a major copper producer since the 1970s. Rajasthan is known for its mineral wealth, and Khetri specifically is renowned for copper ore deposits and mining activities, not mica, bauxite, or limestone.

The United States, Canada, Norway, Switzerland, France, and India are indeed among the world's largest producers of aluminium. These countries have significant bauxite reserves and aluminium smelting industries. Aluminium production requires both bauxite ore and substantial electricity for smelting.

Coal is called 'Black Diamond' due to its black, lustrous appearance and high economic value as a fuel source. This metaphorical name emphasizes its importance in industrial and energy sectors.

Canada is consistently among the world's largest uranium producers and exporters, with significant mining operations concentrated in Saskatchewan. While Canada produces other minerals including copper and gold, it has been particularly dominant in global uranium production for decades.

Jharia, located in the Dhanbad district of Jharkhand (formerly Bihar), is famous for its coal reserves and has India's oldest coal mines. It is known for one of the largest coal deposits in the country and ongoing coal mine fires. Option B (Coal) is correct.

Hematite (Fe2O3) and Magnetite (Fe3O4) are both principal ores of iron. Hematite is the most widely used ore for iron extraction, while magnetite is a high-grade iron ore with magnetic properties. Gold, zinc, and silver have different ore minerals - gold is found in quartz veins, zinc in sphalerite, and silver often in argentite.