Question

India has the world's largest deposits of thorium in the form of

• A. rutile
• B. magnesite
• C. lignite
• D. monazite

Answer 1

The Correct Option is D

To determine which form contains the largest deposits of thorium in India, it's essential to understand the characteristics and occurrences of thorium within natural minerals. Thorium is a mildly radioactive metallic chemical element found in small amounts in most rocks and soils. However, large deposits are concentrated in specific minerals.

1. Option Analysis:
   • Rutile: Primarily composed of titanium dioxide (TiO₂), rutile is not associated with thorium deposits.
   • Magnesite: This mineral consists mainly of magnesium carbonate (MgCO₃). It has no known correlation with thorium deposits.
   • Lignite: A form of coal, lignite is a soft brownish coal showing traces of plant structure, but it also does not contain significant thorium deposits.
   • Monazite: A phosphate mineral that contains rare-earth metals, and it is known to be rich in thorium content. In fact, monazite is one of the most significant minerals for thorium extraction worldwide.
2. Correct Conclusion:

   Based on the mineralogical content, monazite is confirmed as the mineral that contains large deposits of thorium.

3. Additional Information:
   • Monazite is often found in beach sands in India, particularly in states such as Kerala and Tamil Nadu.
   • India has some of the world's largest reserves of monazite, and thus, significant thorium deposits.

Therefore, the correct answer is monazite.