Consider the following minerals: 1. Bentonite 2. Chromite 3. Kyanite 4. Sillimanite In India, which of the above is/are officially designated as major minerals?
- A. 1 and 2 only
- B. 4 only
- C. 1 and 3 only
- D. 2, 3 and 4 only
Answer: D
Explanation
Bentonite is essentially a highly plastic clay containing not less than 85% clay mineral, montmorillonite. It gets its name from the place where its presence and usages were first discovered, Fort Benton, America. As per Govt. of India Notification S.O. 423(E) dated 10th February 2015 Bentonite has been declared as ‘Minor Mineral’. Chromite (Cr) is the single commercially viable ore of chromium which is chemically known as iron chromium oxide (Fe Cr2O4). Kyanite, Sillimanite and andalusite are unhydrous aluminosilicate minerals that have the same chemical formula Al2O3 but differ in crystal structure and physical properties.