Samarium

Overview

Samarium is element 62 and one of the light rare-earth elements (LREEs), the lanthanides from lanthanum to gadolinium.¹ It was isolated in 1879 by Paul-Émile Lecoq de Boisbaudran from the mineral samarskite, which had been named after a Russian mining official.²

Its main use is in samarium-cobalt (SmCo) permanent magnets. These are much stronger than iron magnets and stay magnetic at high temperatures.² Neodymium-iron-boron (NdFeB) magnets have since largely replaced SmCo magnets.²

Unlike lanthanum, cerium, praseodymium and neodymium, samarium is under Chinese export licensing. Since 4 April 2025, exporters of samarium metal, alloys, oxide, compounds and SmCo magnet materials have needed a license.³ The United States lists samarium individually as a critical mineral. The EU includes it in the "light rare earth elements" group and in its strategic "rare earth elements for magnets" entry.⁴⁵

Where it comes from

Samarium occurs with the other lanthanides, mainly in monazite and bastnaesite. It is recovered by ion exchange and solvent extraction, and the metal can be made by reducing the oxide with barium.² It is a minor component of rare-earth ores. It makes up less than 1% of the rare-earth content of the big bastnaesite deposits at Bayan Obo in China and Mountain Pass in the United States, about 2.5% at monazite deposits such as Mt Weld in Australia, and up to about 5% at the Xunwu ion-adsorption clay deposit in southern China.¹

• Xunwu, China (ion-adsorption clay)5%
• Manavalakurichi, India (monazite)3%
• Mt Weld, Australia (monazite)2%
• Bayan Obo, China (bastnaesite)<1%
• Mountain Pass, United States (bastnaesite)<1%

Each bar is samarium's share of the total rare-earth oxide in that source, as tabulated in the USGS 2020 Minerals Yearbook from earlier deposit studies. Bars are separate deposits and do not add up to a total. Source: 2020 Minerals Yearbook: Rare Earths

USGS does not publish samarium-specific production data. 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, of which China produced about 270,000 t, or 69%.⁶ China also dominated the production of separated rare-earth compounds and metals.¹

• 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 samarium-only figures. World total is the USGS rounded figure; the country estimates sum to 389,310 t. Source: Mineral Commodity Summaries 2026: Rare Earths

What it is used for

• SmCo magnets. Samarium-cobalt magnets use samarium with smaller amounts of gadolinium.¹ They were used in microwave applications and helped shrink devices such as headphones and personal stereos.² The US National Defense Stockpile's potential acquisitions for fiscal year 2025 included 60 t of SmCo alloy.⁶
• Nuclear. Samarium absorbs neutrons and is used in nuclear reactors.²
• Optics. Samarium is used to dope calcium chloride crystals for optical lasers and in infrared-absorbing glass.²
• Lighting. Samarium is used in carbon-arc lighting for studios and projection.²

Grades and forms

Samarium is sold as separated oxide and other compounds, as metal, and as samarium-cobalt alloy and magnets. USGS tracks samarium oxide of at least 99.5% purity.⁶ China's export controls name samarium metal, alloys, targets and permanent-magnet materials (item 1C902.a), samarium oxide and mixtures (1C902.b), and other samarium compounds and mixtures (1C902.c).³

Trade and policy

The United States relied on imports for about 67% of its rare-earth compounds and metals in 2025, and 71% of these imports in 2021–24 came from China.⁶

China's measures name samarium directly:

In the EU, "rare earth elements for magnets" (Nd, Pr, Tb, Dy, Gd, Sm and Ce) is a strategic raw material.⁵ 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.¹²

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.⁶ NdFeB magnets have largely replaced SmCo magnets.² More generally, substitutes exist for many rare-earth uses but are less effective.⁶

Sources

1. 2020 Minerals Yearbook: Rare Earths. U.S. Geological Survey, accessed 2026-10-03. ↩ ↩² ↩³ ↩⁴

2. Samarium: element information, properties and uses. Royal Society of Chemistry, accessed 2026-10-03. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

3. 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. ↩ ↩² ↩³

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

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

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

7. China Publishes the Catalog of Technologies Prohibited or Restricted from Export. ChemRadar (CIRS Group), 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 rare earth export pause nears expiry amid persistent supply concentration. Mining Technology, accessed 2026-10-03. ↩

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

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