Detailed Explanation:

Answer: Option 2 — 1, 2 and 4 only

Monazite is a radioactive mineral that serves as a major source of rare earth elements and thorium. In India, its processing and export are strictly regulated by government bodies due to its strategic importance and radioactive nature. Statement 3 is incorrect because monazite is not found along the entire Indian coastal stretch but is concentrated in specific regions.

✅ Statement 1 – Correct: Monazite is a primary source of rare earth elements like cerium, lanthanum, neodymium, and praseodymium.
✅ Statement 2 – Correct: Monazite contains significant amounts of thorium, making it an important mineral for nuclear energy applications.
❌ Statement 3 – Incorrect: Monazite deposits are not found along the entire Indian coast; major deposits are concentrated in Kerala, Tamil Nadu, and Odisha.
✅ Statement 4 – Correct: Indian Rare Earths Limited (IREL), a Government of India PSU under the Department of Atomic Energy, is the only authorized entity to process and export monazite under the Atomic Energy Act.

📝 Short Notes: Monazite in India

• Composition: Brown crystalline mineral containing cerium, lanthanum, thorium, and other rare earth elements
• Occurrence: Found in placer deposits along coastal sands; main deposits in Kerala (Chavara, Manavalakurichi), Tamil Nadu, and Odisha
• Economic Importance: Source of rare earths used in high-performance magnets for wind turbines, electric vehicles, and robotics
• Strategic Importance: Contains thorium (8-10%), crucial for India's three-stage nuclear power program
• Regulatory Framework: Governed by Atomic Energy Act and Atomic Energy (Radiation Protection) Rules 2004; export requires AERB license
• Processing Entity: Indian Rare Earths Limited (IREL) is the sole government-authorized body for monazite extraction, processing, and export