Consider the following minerals:
- Bentonite
- Chromite
- Kyanite
- Sillimanite
In India, which of the above is/are officially designated as major minerals?
- 1 and 2 only
- 4 only
- 1 and 3 only
- 2, 3 and 4 only
Explanation
Bentonite is incorrect
- A mineral is a naturally occurring substance characterized by unique chemical and physical properties, composition, and atomic structure. In India, minerals are classified as major or minor under the Mines and Minerals (Development and Regulation) Amendment Act, 2015, to assess output value in the mining and quarrying sector.
- As per Government of India official notification released in 2015 Bentonite (locally known as multani mitti or Fuller’s earth) has been declared as ‘Minor Mineral’.
Chromite is correct
- Chromite is a major mineral. It is a dark grey, metallic, oxide mineral often mistaken for magnetite due to its metallic lustre and occasional magnetic properties. It can be found in basic igneous rocks, as well as in metamorphic and sedimentary rocks created by weather-affected chromite-containing rocks. It is a crucial metal used to make hard, tough, and chemically resistant steel. The chromium extracted from chromite is used in chrome plating and alloying to produce corrosion-resistant superalloys, nichrome, and stainless steel. More than 96% of chromite resources are located in Odisha (Jajpur, Kendujhar, and Dhenkanal).
Kyanite is correct
- Kyanite is a major mineral. It occurs in metamorphic aluminous rocks. It has high-temperature resilience.
- Its quality relies on aluminium content: more aluminium, higher grade. It is primarily used in metallurgical, ceramic, glass, and cement industries. It is also used to make spark plugs in automobiles. Jharkhand, Maharashtra, and Karnataka produce nearly all of India’s kyanite. Jharkhand’s Singhbhum district leads in kyanite production (4/5th), followed by Maharashtra and Karnataka.
Sillimanite is correct
- Sillimanite is a major mineral. It is mainly composed of aluminium, silicon, and oxygen. It is commonly found in metamorphic rocks like schists, gneisses, and granulites. It is utilised in ceramics, glass, and metal production for its high melting point and thermal stability. It is ideal for lining kilns, furnaces, and high-temperature industrial processes due to its heat resistance, chemical inertness, and low electrical conductivity. It is valued as a gemstone but is relatively rare and not widely commercially available.
- Orissa is India’s largest producer of sillimanite, with Ganjam district contributing significantly.
