Byproduct Risk in Criticality Assessments
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Byproduct risk is the risk that a mineral's supply cannot respond to its own price because it is recovered from another metal's ore. The published criticality formulas include no byproduct term, but USGS publishes the host commodity for each mineral on the 2025 list, and 35 of the 60 are byproducts or co-products. The 2025 market shows the effect: Europe's average tellurium price rose 84% while U.S. recovery of copper telluride fell with copper cathode output.
35 of 60
listed minerals are produced as byproducts or co-products
+84%
rise in the average tellurium price in Europe in 2025, while U.S. copper telluride recovery fell
+71%
rise in Europe's germanium metal price between January and October 2025, from $3,150 to $5,380 per kilogram
2.5x
the antimony price in 2025 against August 2024: $25 per pound on average against $9.80
Why is byproduct supply less responsive to price?
A byproduct is recovered where the host metal is already mined and smelted, so its volume follows the host's output and the plant's recovery circuit. USGS says tellurium supply is directly affected by the supply of the materials it comes from, primarily copper, and gallium is recovered predominantly from bauxite processing. The Federal Register notice adds that a number of byproducts are increasingly recovered as co-products, which contribute significant value to the mining or processing operation, and that is where new investment appears. The byproducts page lists the hosts.
How did host-linked metals behave in 2025?
The table records USGS's 2025 observations for metals that are byproducts. Price rises coincided with trade controls, so they do not isolate the byproduct effect, but they show what supply did.
| Mineral | Host metals (Federal Register) | What USGS recorded in 2025 |
|---|---|---|
| Tellurium | Copper, lead, nickel, platinum, zinc | Average price in Europe up 84% to $150 per kilogram and in U.S. warehouses up 60% to $120; U.S. copper telluride recovery decreased with lower copper cathode output. |
| Gallium | Bauxite and zinc | China produced 99% of primary low-purity gallium; U.S. gallium metal imports more than doubled at about $580 per kilogram. |
| Germanium | Zinc and coal fly ash | Production data limited and hard to verify; Europe's metal price rose from $3,150 to $5,380 per kilogram between January and October. |
| Indium | Zinc | Exports of unwrought indium fell 72% year on year to September 2025; the U.S. price averaged $390 per kilogram, up 11%. |
| Rhenium | Molybdenum, copper | U.S. primary production rose 5% to 9,800 kilograms with molybdenum roasting; secondary rhenium from scrap supplements it. |
| Antimony | Lead, gold, other base and precious metals | Price rose from $9.80 per pound in August 2024 to $18.10 in December and averaged $25 in 2025; a Montana mine started mining in 2025 and an Idaho mine broke ground. |
| Cobalt | Nickel, copper | Congo export ban and quotas; U.S. spot cathode price up from $16.77 to $21 per pound. |
Sources: Federal Register for hosts; USGS Mineral Commodity Summaries 2026 chapters on tellurium, gallium, germanium, indium, rhenium, antimony and cobalt.
How do the frameworks handle byproducts?
As published, the EU formulas and the USGS 2025 method describe no separate byproduct term. The EU captures part of the effect through high supply concentration and import reliance, and USGS treats it in the narrative: its 2025 notice publishes the host-commodity table so that readers can see which minerals depend on other metals. A byproduct that is also a minor part of a large host's revenue may not justify a dedicated plant, which is why government grants and fund agreements, such as the $29.9 million gallium and scandium recovery award and Canada's Trail agreement, have focused on adding recovery to existing operations.
Frequently asked questions
What is byproduct risk?
Byproduct risk is the risk that supply of a mineral is limited because it is recovered only as a byproduct of another metal, so its output follows the host metal rather than its own price. Tellurium and copper, and gallium and bauxite, are examples.
How many critical minerals are byproducts?
The 2025 U.S. critical minerals list marks 35 of its 60 minerals as byproducts or co-products, including all 15 individually listed rare earths and four of the five platinum group metals.
Do criticality formulas include byproduct dependence?
Neither the EU formulas nor the USGS 2025 method has a separate byproduct term. The Federal Register notice publishes the host commodity of each listed mineral as supporting information.
Can byproduct supply be increased?
Only by raising output of the host metal or by adding a recovery plant to an existing operation. USGS reports such projects for gallium, including a $29.9 million Department of War award for a Louisiana demonstration plant and up to $6 million of Department of Energy research funding.
Sources
Read on October 13, 2026. Figures on this page come from these documents; where a number is an estimate, the source says so.
