Thulium
One of the rarest rare earths; used in medical lasers and portable X-ray devices.
Thulium-doped fiber amplifiers extend optical bandwidth in some networks.
Mined alongside other rare earths; China dominates separation (≈85% of refining in 2025).
Where it's produced
Share of 2025 world mine production (rare-earth oxide equivalent) (metric tons) · figures are for Rare earths (total, REO). Source: USGS MCS 2026.
Where the reserves are
Share of known economic reserves (metric tons). World total: 85M t. ≈ 218 years at 2025 output.
Who calls it critical
Membership on each government list. “Strategic” marks a higher tier where the list has one; “group” means included as part of a group such as rare earths or PGMs.
Thulium: key questions
- Where is thulium mined or produced?
- According to USGS 2025 data, the largest producers are China (69%), United States (13%) and Australia (7.4%) of world mine production (rare-earth oxide equivalent).
- Is thulium a critical mineral?
- Thulium appears on 8 of the 10 official lists we track (United States, European Union, United Kingdom, China, Japan, India, Australia, Canada).
- Is thulium in short supply?
- Our supply status: Watch. Mined alongside other rare earths; China dominates separation (≈85% of refining in 2025).
- Why does thulium matter for AI infrastructure?
- Thulium-doped fiber amplifiers extend optical bandwidth in some networks.
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