Heavy Rare Earths (HREE): The Supply-Constrained Cluster
Heavy rare earths (HREE) are the scarcer, higher-atomic-number rare earths, and they command much higher prices than light rare earths. They comprise the nine elements with higher atomic numbers: europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). HREEs are significantly scarcer than LREEs, more difficult to process, and command premium prices. Dysprosium and terbium face the tightest supply constraints in the REE complex due to high-temperature magnet demand.
Why HREEs Command Price Premiums
Heavy rare earths sell for far more per kilogram than light rare earths: in 2025, USGS annual averages were about $239/kg for dysprosium oxide and $1,010/kg for terbium oxide, against $73/kg for neodymium oxide. This reflects three factors:
- Lower crustal abundance: HREEs are genuinely less abundant than LREE in most ores.
- Higher separation costs: Chemical separation of HREEs is more challenging. Solvent extraction efficiency drops for higher atomic numbers.
- Geopolitical concentration: HREE processing is even more China-dominated than LREE. New HREE separation capacity is rare.
The Nine HREE Elements
Europium (Eu) & Gadolinium (Gd)
Phosphor applications (Eu) and MRI contrast agents (Gd). Stable demand, moderate pricing. Eu guide | Gd guide
Dysprosium (Dy)
CRITICAL BOTTLENECK. High-temperature magnet performance enhancer. Tightest supply constraint in REE complex. Premium pricing. Dy guide
Terbium (Tb)
CRITICAL BOTTLENECK. Ultra-high-purity magnet additive. Even scarcer than Dy. Extreme price premium. Tb guide
Holmium (Ho) & Erbium (Er)
Magnets, lasers, optical fiber applications. Moderate demand and pricing. Ho guide | Er guide
Thulium (Tm) & Ytterbium (Yb)
Portable X-ray, lasers, niche applications. Low volume, specialty markets. Tm guide | Yb guide
Lutetium (Lu)
PET scanners, catalysts, specialty applications. Smallest production volume among HREE. Lu guide
HREE Market Dynamics
Supply Concentration
China does almost all heavy rare earth separation, with Lynas in Malaysia the main producer outside China since 2025. Non-China HREE supply projects are actively pursued but face long development timelines and technical hurdles. This concentration creates geopolitical leverage and price volatility.
Demand Drivers
- High-temperature magnets (Dy, Tb): EV motors and wind turbines operating at elevated temperatures require Dy/Tb doping. Structural demand growth.
- Phosphors (Eu, Y): Display backlights, phosphorescent screens. Cyclical demand tied to consumer electronics.
- Specialty applications: MRI agents, PET scanners, lasers. Steady but low-volume demand.
Dysprosium and Terbium: The Critical Bottleneck
Dy and Tb merit special attention. These two elements represent the tightest supply constraint in the entire REE complex.
Dysprosium (Dy)
- Supply: Mostly from ionic clays in southern China and Myanmar, separated in China; Lynas has produced separated dysprosium in Malaysia since 2025.
- Demand: High-temperature NdFeB magnets for EV motors, wind turbines and industrial uses; magnet makers are reducing dysprosium per magnet through grain boundary diffusion.
- Supply risk: Export licensing since April 2025 and conflict in Myanmar make non-China supply a policy priority.
- Pricing: About $239/kg for dysprosium oxide in 2025 (USGS estimate), roughly three times neodymium oxide.
- Investment angle: New Dy supply projects or separators with Dy capability command premium valuations.
Terbium (Tb)
- Supply: Scarcer than dysprosium in most ores; separated mainly in China, with Lynas producing outside China since 2025.
- Demand: Specialty magnet applications. Lower volume than Dy but equally supply-constrained.
- Supply risk: Subject to Chinese export licensing since April 2025.
- Pricing: About $1,010/kg for terbium oxide in 2025 (USGS estimate), roughly four times dysprosium oxide.
- Investment angle: Tb supply projects are rarities. Extreme supply constraints support premium equity valuations.
HREE Investment Strategy
HREE investing requires distinguishing between high-constraint elements (Dy, Tb) and commodity HREE (Eu, Gd).
Risks and Considerations
- China dominance: Reducing dependency on Chinese HREE separation takes time. New capacity faces capex and technical challenges.
- Cyclical demand: HREE demand is cyclical through EV and electronics cycles. Producers face downside risk during slowdowns.
- Technology substitution: Alternative magnets or recycling could reduce HREE demand. Risk is low through 2030 but worth monitoring.
- Price volatility: HREE prices swing sharply. Investors must size positions for downturns.
Equity Exposure
HREE investment is accessed through:
- Integrated REE producers: Companies with both LREE and HREE exposure. REE stock list
- HREE-focused projects: New separation plants or magnet REE developers focused on Dy/Tb supply.
- REE ETFs: Bundled exposure to REE supply chain. ETF comparison
Heavy Rare Earths FAQ
What are heavy rare earths?
Heavy rare earths (HREE) are the higher-atomic-number rare earths, from europium to lutetium, usually with yttrium. They are scarcer than light rare earths, come mainly from ionic clays in southern China and Myanmar, and include dysprosium and terbium, which keep NdFeB magnets working at high temperatures.
Which rare earth elements are heavy rare earths?
The heavy rare earths are europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu). Yttrium is usually grouped with them. Classifications vary between sources.
Why are heavy rare earths so valuable?
Heavy rare earths are valuable because they are scarce in most ore bodies, hard to separate, and needed for high-temperature magnets. USGS estimated 2025 average prices of about $239 per kilogram for dysprosium oxide and $1,010 per kilogram for terbium oxide, against about $73 per kilogram for neodymium oxide.
Are heavy rare earths subject to Chinese export controls?
Yes. China introduced export licensing for several medium and heavy rare earths, including dysprosium and terbium, in April 2025. Prices outside China have since risen far above Chinese domestic prices. See the China export controls page for the current status.
Key Takeaways
- Heavy rare earths are genuinely scarcer than light rare earths and sell for several times more per kilogram.
- Dysprosium and terbium are the critical bottlenecks, facing decade-long supply deficits.
- New HREE separation capacity outside China is a policy priority and investment focus.
- HREE investors should differentiate between high-constraint (Dy, Tb) and commodity HREE (Eu, Gd).
- Supply-chain position matters: mining vs. separation determines margin and risk profile.