Rare earths comprise a group of 17 elements with common characteristics; they are not in fact rare, but are not commonly found in concentrated form. Mining and processing are dominated by China.

“Applications of the rare-earth elements have grown dramatically over the past four decades … as substitutes are inferior or unknown, the rare-earth elements have acquired a level of technological significance much greater than expected from their relative obscurity” (United States Geological Service).

Processing rare-earth ores is complex. There are several rare-earth ores (e.g. monazite), each typically containing several rare-earth elements (e.g. the most common form of monazite contains lanthanum, cerium and neodymium). These elements are typically in the form of oxides. The ore is initially concentrated, to increase its rare-earth content. The different rare-earth oxides are then separated from each other. Finally, the different oxides are reduced to their metallic form (e.g. neodymium, dysprosium).

Processing steps include grinding; gravity, magnetic and/or electrostatic separation; flotation; roasting; leaching; ion exchange; solvent extraction; and calcio-thermic and/or electrolytic reduction. The resulting rare-earth metals are then alloyed with each other for specific applications (e.g. permanent magnets).

More than 40% of rare earths are used in permanent magnets (that is, magnets that retain their magnetic field indefinitely). Rare-earth magnets are the strongest type of permanent magnet, with two types.

The first is based on neodymium, sometimes including praseodymium and, where resistance to high temperatures is required, dysprosium and/or terbium. Neodymium-based magnets are the main form of rare-earth magnets.

The second is based on samarium, with samarium-cobalt magnets able to sustain very high temperatures (550 degrees plus). Uses include in jet engines, missile systems such as Israel’s Iron Dome, the bunker-buster bombs used by the US against Iran in June, and Virginia submarines, the latter to be purchased by Australia under the AUKUS partnership.

“Neodymium and samarium … have a disproportionate influence on all high-technology businesses, especially the defence industry” (Lt Colonel Justin Davey, US Air Force, writing over 10 years ago).

Rare earths are widely used (in the form of magnets and in other ways) for products including  automobiles, robotics, electronics, medical equipment, loud speakers, hard-disc drives, refrigerators, jewellery, pumps and wind turbines. Smart phones each contain around eight rare earths.

Chinese dominance of rare earths is becoming of increasing concern to other countries, with the US government pushing for a substantial domestic increase in the mining and processing of rare earths. The US currently has one producer: Mountain Pass in California.

In June 2025, the US and China reached an agreement that entails the relaxing of restrictions on Chinese exports of rare earths. Automobile plants in the US, Germany and Japan have already been adversely affected by Chinese rare-earth restrictions.

For the foreseeable future, the issue of rare earths will play an important role in China’s relations with the rest of the world. Foreshadowing this in 1992, China’s then-leader, Deng Xiaoping, said: “The Middle East has its oil, China has rare earths”.