According to the United States Geological Survey (USGS), most REEs are not as rare as their name suggests and are found in abundance in the Earth''s crust. However, they''re rarely found in concentrations that are economically viable for mining.

• They were named "rare-earth elements" because most were identified during the 18^th and 19^th centuries as "earths Elements" and, in comparison to other "earths Elements," such as lime or magnesia, they were relatively rare.

• Earth''s Elements are defined as materials that cannot be changed further by heat.

• Rare Earth Elements (RREs): As per the International Union of Pure and Applied Chemistry (IUPAC) in 2005, are a group of 17 elements. 
• These elements share similar properties such as high density and high conductivity.
• cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium I, ytterbium (Yb), and yttrium (Y).
• Source: Main sources of REEs are minerals such as bastnasite, loparite and monazite. 

Applications

1. Permanent Magnets

• • Neodymium-Iron-Boron (NdFeB) magnets are the strongest commercial permanent magnets.
  • They retain magnetic properties even at high temperatures (~230°C).
  • Applications: automobile subsystems (ABS brakes, power steering, electric windows, audio speakers), consumer electronics (hard drives, CD-ROMs, digital cameras).

2. Electronics and Displays

• • REEs are integral to smartphones, laptops, LEDs, and flat-panel displays.
  • Phosphorescent REEs (Europium, Yttrium, Terbium) are used in phosphors for TV screens, monitors, and stadium scoreboards.
  • Lanthanum is vital for optical lenses, forming ~50% of digital camera lenses.
  • Erbium is crucial in fibre-optic cables and laser repeaters.

3. Green Technologies

• • REEs enable low-carbon technologies like wind turbines and electric vehicles.
  • Lanthanum alloys form anodes in nickel-metal hydride batteries used in hybrid cars.
  • Cerium catalysts are employed in catalytic converters to reduce vehicular emissions.
  • REEs thus support India’s and global net-zero emission goals.

4. Petroleum Refining

• • Lanthanum-based catalysts are widely used in refining processes to improve fuel quality.

5. Glass Industry

• • The largest consumer of REE raw materials.
  • REEs are used for glass polishing and as additives to impart colour and optical properties.

6. Water Purification

• • Cerium compounds bind strongly with phosphorus, making them effective in water purification systems.

7. Healthcare

• • REEs are applied in MRI machines, laser scalpels, antiseptic dressings, and cancer therapies.

8. Defence and Space

• • Used in satellite communication, guidance systems, aircraft structures, and advanced weaponry.

9. Steel Making

• • Mischmetal (mixed oxides of cerium, lanthanum, neodymium, praseodymium) is used to remove impurities and produce special alloys in steel manufacturing.

10. Other Specialized Uses

• • Promethium → beta radiation sources.
  • Samarium → high-temperature magnets.
  • Europium → fluorescent lighting

Geostrategic significance of recent export control of REE

• To gain upper hand in the tariff war: Retaliation against the USA''s reciprocal tariffs, which may hurt the Chinese industry due to a fall in exports.
• Implications on Critical technologies: Yttrium and Dysprosium, which are widely used in the manufacturing of jet engine components, defence equipment, and advanced electronics.

• For importing nations, supply disruptions can cripple industries, inflate costs, and delay technological advancements.

• Global supply Chain disruption: Due to crunch in supply may affect major REE-consuming countries like the US, Japan, Vietnam, and Germany.
• Weaponisation of REE: China first weaponized rare earths in 2010 when it banned exports to Japan over a fishing trawler dispute.
• Between 2023 and 2025, China began imposing export restrictions of strategic materials including gallium, germanium etc.
• Geostrategic alternatives: Longer-term consequences include diversification of supply, reshoring and friend-shoring of manufacturing, and acceleration of recycling.
• Reshoring means bringing back the production to the home country, and Friend shoring is where businesses source or produce goods in countries with shared values.
• Countries are seeking alternatives in Africa (notably the Democratic Republic of Congo and Malawi), South America, and Australia.

Global efforts to reduce dependence on China for REE

• Critical Minerals Mapping Initiative (CMMI) in 2019: Formed by the US, Australia and Canada to conduct research on critical mineral resources, including REEs.
• The UN Secretary-General''s Panel on Critical Energy Transition Minerals: To discuss proper management and a roadmap for Critical energy transition minerals such as rare earth elements.
• Mineral Security Partnership (MSP): Partnerships between countries, including India to focuses on the supply chain of minerals and metals that are most relevant for advanced technologies, defence, energy, and industrial processes

To reduce dependence on China for rare earth elements (REEs), countries may build strategic inventories, boost domestic production, and invest in advanced refining technologies. Deep-sea exploration and recovery from secondary sources offer additional supply avenues. Streamlined regulations and private sector incentives are essential to accelerate self-reliance in the REE value chain.