About the element

Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in native form as elemental crystals. Tellurium is far more common in the Universe as a whole than on Earth. Its extreme rarity in the Earth’s crust, comparable to that of platinum, is due partly its formation of a volatile hydride that caused tellurium to be lost to space as a gas during the hot nebular formation of Earth, and partly to tellurium’s low affinity for oxygen that causes it to bind preferentially to other chalcophiles in dense minerals that sink into the core.


Key facts

  • Symbol: Te
  • Atomic number: 52
  • Atomic mass: 127.6 u


Most of the targeted by-products elements in the ION4RAW project are Critical Raw Materials (CRMs). CRMs combine raw materials of high importance to the EU economy and of high risk associated with their supply.

Tellurium is not part of the EU 2020 Critical Raw Materials List. Its criticality is considered to be medium.

Main uses of Tellurium

Photovoltaic cells: tellurium is used in manufacturing thin films essential to photovoltaic solar cells due to its enhanced electrical conductivity and its efficiently in absorbing sunlight and converting it into electricity.

Thermoelectric devices: these components can turn a temperature variation into electricity or the reverse. Uses include applications related to power generation (heat pump, cooling), infrared detectors, gamma- and X-ray detection.

Also used… as an additive in steel or copper alloys to improve machinability, in the vulcanisation of rubber, in glass and ceramics pigments, in rewritable CDs or DVDs, as a catalyst in oil refining, etc.

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

The map below indicates few areas of potential interest for Tellurium 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.