Germanium
A zinc and coal by-product used in fibre optics, infrared lenses and space solar cells, whose price doubled under Chinese export curbs.
Tech & minor metals · No. 39
- EU strategic
- EU critical 2023
- US critical 2025
- India critical 2023
- HHI 8,726 · highly concentrated
The first transistor, built in 1947, used germanium; today China supplies 93% and its price roughly doubled in 2025.
Chart: Illustration: Germanium
Where it comes from
Chart: Map of where it comes from
Germanium is never mined for itself. Zinc smelters catch it in their residues and some producers recover it from coal ash; world output was about 150 t in 2024.
Three things to know
- Germanium lets infrared light through, so thermal-imaging cameras use germanium lenses, and its dioxide raises the refractive index of optical-fibre cores.
- World output rose from 96 t in 2020 to 163 t in 2023, then slipped to 150 t in 2024.
- It shows three warning signs at once: by-product supply, concentrated production and minimal end-of-life recycling, so the EU, US and India all list it.
The journey
- 1 Zinc ore, coalTrace germanium in sphalerite and lignite
- 2 Residue or ashCaught at zinc smelters or from ash
- 3 ConcentrateGermanium-rich residues upgraded
- 4 ChlorinationTurned into germanium tetrachloride
- 5 Dioxide and metalRefined to 5N metal and beyond
- 6 ProductsFibre preforms, infrared lenses, wafers