About the element

Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard-brittle, grayish-white metalloid in the carbon group, chemically similar to its group neighbours silicon and tin. Pure germanium is a semiconductor with an appearance similar to elemental silicon.


Key facts

  • Symbol: Ge
  • Melting point: 938.2 °C
  • Atomic number: 32
  • Atomic mass: 72.64 u

Germanium has five naturally occurring isotopes, 70Ge, 72Ge, 73Ge, 74Ge, 76Ge.


Most of the targeted by-products elements are Critical Raw Materials (CRMs). CRMs combine raw materials of high importance to the EU economy and of high risk associated with their supply.

Germanium is part of the EU 2020 Critical Raw Materials List. Its criticality is considered to be medium.

Main uses

Optical fibre and infrared optics: germanium is used in optical fibre for high-speed telecommunications and in infrared optics with military applications, including night-vision devices, as well as advanced firefighting equipment, satellite imagery sensors and medical diagnostics.

Solar cells, in particular in space-based applications, while the role of Germanium-based solar cell terrestrial installations is also expected to grow.

And also: in gamma ray detectors and organic chemistry, phosphors, metallurgy, and chemotherapy, etc.

Outside of the EU, Germanium is widely used as a catalyst in the production of PET plastics.

Map of kernel density of weighted Germanium scores in Europe by DBQ geostatistical method

The map below indicates few areas of potential interest for Germanium prospection in Europe. It is part of the “Mapping of by-product potential evaluation” (Deliverable 2.1) led by consortium member BRGM.

This map was made based on the current available data and the DBQ geostatistical method, performing a kernel density calculation. The kernel density calculation is a statistical tool which estimates the probability density function of a random variable.