Cerium

Overview

Cerium is a grey, reactive metal that tarnishes readily and ignites when heated. It is the most abundant of the lanthanides: more abundant in the Earth's crust than tin or lead, and almost as abundant as zinc.¹ It is a light rare-earth element (LREE), the group that runs from lanthanum (atomic number 57) to gadolinium (64).²

Most of cerium's uses rely on its oxide rather than the metal. Cerium oxide is the main ingredient of glass-polishing compounds and an important component of catalysts, including those in vehicle catalytic converters.²¹

Cerium is mined alongside the other rare earths and makes up roughly half of the rare-earth content of the main bastnaesite and monazite ores.² It is listed as critical in both major Western economies: the United States names cerium individually on its 2025 critical minerals list, and the EU includes it among the "rare earth elements for magnets" on its strategic list.³⁴

Where it comes from

The main commercial rare-earth minerals are bastnaesite, loparite, monazite, xenotime and lateritic ion-adsorption clays. How much of each element they contain varies a lot from one deposit to another.² Cerium is the largest component of bastnaesite and monazite. It is about 50% of the rare-earth content at Bayan Obo in China and Revda in Russia, and about 48% at Mountain Pass in the United States. Southern Chinese ion-adsorption clays contain only a few percent.²

• Cerium50%
• Lanthanum23%
• Neodymium19%
• Praseodymium6%
• Samarium<1%
• Other rare earths1%

Share of total rare-earth oxide content, as tabulated in the USGS 2020 Minerals Yearbook from earlier deposit studies. "Other rare earths" is europium, gadolinium, terbium and dysprosium. Source: 2020 Minerals Yearbook: Rare Earths

USGS does not publish separate cerium production figures. It reports rare earths as a group in rare-earth-oxide (REO) terms. World mine production was an estimated 390,000 t REO in 2025, and China accounted for about 270,000 t, or 69%. The United States produced about 51,000 t in mineral concentrates, from bastnaesite mined at Mountain Pass, California; monazite was also recovered from heavy-mineral sands in the southeastern states.⁵ China also dominated the production of separated rare-earth compounds and metals.²

• China270,000 t · 69%
• United States51,000 t · 13%
• Australia29,000 t · 7%
• Burma22,000 t · 6%
• Thailand4,800 t · 1%
• Other countries12,510 t · 3%

USGS reports rare earths only as a group, in rare-earth-oxide (REO) terms; these are not cerium-only figures. World total is the USGS rounded figure; the country estimates sum to 389,310 t. Source: Mineral Commodity Summaries 2026: Rare Earths

USGS estimates world rare-earth reserves at more than 75 million t REO, of which China holds 44 million t.⁵

What it is used for

Globally, the largest rare-earth uses by quantity are magnets, catalysts, polishing and metallurgy. Cerium is central to the second and third of these.²

• Polishing. Polishing compounds use mainly cerium, with lesser amounts of lanthanum.²
• Catalysts. Lanthanum and cerium are the main rare earths used in catalysts.² Cerium oxide is used in vehicle catalytic converters and in self-cleaning oven linings.¹
• Glass and ceramics. The glass sector uses lanthanum, cerium and erbium, in that order of quantity, and ceramics use some cerium alongside yttrium.²
• Alloys. Cerium makes up nearly half of mischmetal, a light rare-earth alloy best known for lighter flints, because it gives off sparks when struck.¹ Ferrocerium and rare-earth metals are used in metallurgical applications.²
• Other uses. Cerium sulfide is a non-toxic red pigment.¹ Smaller amounts of cerium go into batteries, where lanthanum is the main rare earth used.²

In the United States, catalysts are the leading use of rare earths. Most US consumption of light rare earths is in the form of cerium and lanthanum compounds for catalysts, ceramics, glass and polishing compounds.⁵²

Grades and forms

Cerium is sold as separated oxide and other compounds, as polishing powders, and as metal or alloys. It also reaches the market in mixed forms such as mischmetal. USGS tracks cerium oxide of at least 99.5% purity and mischmetal with about 65% cerium and 35% lanthanum.⁵

Trade and policy

The United States relied on imports for about 67% of its rare-earth compounds and metals in 2025. Between 2021 and 2024, 71% of these imports came from China. Many of the rest came from Estonia, Japan and Malaysia, but were made from concentrates and intermediates produced in Australia, China and elsewhere.⁵ Cerium compounds have their own US tariff line, 2846.10.⁵

China's rare-earth export measures have so far focused on medium and heavy rare earths and on technology. Cerium itself is not one of the elements under licensing:

In the EU, cerium is covered by two entries in the Critical Raw Materials Act: the critical-materials group "light rare earth elements" and the strategic entry "rare earth elements for magnets", which lists Nd, Pr, Tb, Dy, Gd, Sm and Ce.⁴ Strategic raw materials carry 2030 benchmarks: 10% of EU consumption from EU extraction, 40% from EU processing and 25% from recycling, and no more than 65% from any single third country.¹¹

This section is factual background, not legal or trade-compliance advice.

Recycling and substitution

Only limited quantities of rare earths are recovered from end-of-life products, mainly from batteries, permanent magnets and fluorescent lamps.⁵ Substitutes exist for many rare-earth uses but are generally less effective.⁵

Sources

1. Cerium: element information, properties and uses. Royal Society of Chemistry, accessed 2026-10-03. ↩ ↩² ↩³ ↩⁴ ↩⁵

2. 2020 Minerals Yearbook: Rare Earths. U.S. Geological Survey, accessed 2026-10-03. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³

3. Final 2025 List of Critical Minerals. Federal Register, accessed 2026-10-03. ↩

4. EU critical raw materials. European Commission Joint Research Centre (RMIS), accessed 2026-10-03. ↩ ↩²

5. Mineral Commodity Summaries 2026: Rare Earths. U.S. Geological Survey, accessed 2026-10-03. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

6. China Publishes the Catalog of Technologies Prohibited or Restricted from Export. ChemRadar (CIRS Group), accessed 2026-10-03. ↩

7. Announcement No. 18 of 2025 on implementing export control on medium and heavy rare earth related items. Ministry of Commerce of the People's Republic of China, accessed 2026-10-03. ↩

8. China Imposes Extraterritorial Export Control Measures Over Rare Earth Items. Jones Day, accessed 2026-10-03. ↩

9. China Temporarily Suspends Export Controls on Key Raw Materials, Including Rare Earths, Lithium Batteries, and Diamonds. CIRS Group, accessed 2026-10-03. ↩

10. China's Rare Earth Processing Dominance and What the Trump-Xi Summit Didn't Change. Bloomsbury Intelligence and Security Institute, accessed 2026-10-03. ↩

11. Regulation (EU) 2024/1252 (Critical Raw Materials Act). EUR-Lex, accessed 2026-10-03. ↩