The rarest stable rare earth — and the last one out of the separation line.
Lutetium is the heaviest and least abundant of the stable lanthanides, recovered last in heavy-rare-earth separation circuits. Global output is therefore capped by total HREE processing throughput rather than dedicated lutetium mining. It plays two distinct roles: as a niche industrial material in scintillator crystals and specialty optics, and, through the radioactive isotope lutetium-177, as a fast-growing input into targeted cancer radiotherapy.
Sources: Hamato et al., 2026 — Lutetium-oxide PET scintillators (PMC)DailyMed — LUTATHERA prescribing information
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Isotope reference
Lutetium-175 (¹⁷⁵Lu) is the stable, overwhelmingly predominant naturally occurring lutetium isotope. CIAAW lists it at 0.97414(5) (about 97.414%) and NIST lists the isotope mass as 174.940770 u.
| Isotope | Natural abundance | Half-life / status |
|---|---|---|
| ¹⁷⁵Lu | 97.414(5)% | Stable |
| ¹⁷⁶Lu | 2.586(5)% | 3.57(14) × 10¹⁰ years |
CIAAW amount-fraction uncertainties are shown in parentheses where reported. “Stable” means no radioactive half-life is assigned in this table.
Natural lutetium also contains a small fraction of radioactive Lu-176. Lu-175 is not Lu-177: Lu-177 is a different radioactive medical isotope used in radiopharmaceuticals, and claims about Lu-177 must not be applied to Lu-175.
Stable Lu-175 does not make every lutetium compound harmless. Chemical-form hazards and any intentionally radioactive or activated material must be assessed separately.
Supplier documentation
This is a supplier SDS for lutetium(III) oxide (Lu₂O₃), not a Lu-175 isotope certificate. The linked Fisher Scientific listing identifies a laboratory chemical supplied through Avocado Research Chemicals; verify the current lot documentation before use.
The linked SDS identifies catalog 10912 and the Lu₂O₃ chemical form. Product grade, package size, and particle-size details must be checked against the current supplier lot.
An SDS is product-, supplier-, grade-, and form-specific. It does not turn an isotope label into a radiological or chemical safety determination, and Lu-175 must not be confused with Lu-177 radiotherapy material.
Lutetium oxide, 99.99% minimum, free on board • As of 2025 average
The USGS-reported average held between $780–$829/kg from 2022–2024, then rose to $888/kg in 2025, an increase of roughly 14% year on year. China’s April 2025 export controls added pressure to an already constrained byproduct supply chain.
Source: USGS Mineral Commodity Summaries 2026, Rare Earths (Heavy) (February 2026)
The primary traded form and a feedstock for scintillator crystals and specialty optics.
A soluble precursor for other lutetium compounds and catalysis research.
Used in fluoride-based optical and scintillator materials.
Direct Answers
Lutetium is used in scintillator crystals for PET scanners and industrial detectors and, through the isotope lutetium-177, in targeted radionuclide cancer therapy. It also has minor catalyst uses.
The USGS reported a 2025 average of $888/kg for lutetium oxide at 99.99% minimum purity, free on board. This is historical context rather than a live quote.
Lutetium is recovered last in heavy-rare-earth separation, so output is capped by total HREE processing volume rather than dedicated mining. China’s April 2025 export controls add a further supply constraint.