Home Element Metal Erbium


What is erbium?

Erbium is a chemical element or rare earth metal in the periodic table with the symbol Er and atomic number 68. It is a soft, silvery metallic element that uses for making optical fiber glasses to amplify optical communication signals. Erbium is also alloyed with vanadium to lower its hardness and improves its workability.

Erbium element or rare earth metal symbol Er, uses, properties, and facts

Erbium was discovered in 1843 by Swedish chemist Carl Gustav Mosander from the mineral Ytterby in a gadolinite mine found in Sweden. It was one of three elements found in Ytterby that separated from the mineral gadolinite. He discovered the oxide form of the metal and named it erbia after the village of Ytterby.

Where is erbium found?

Erbium is never found as a free element in nature but an extractable amount is found in rare-earth minerals monazite and bastnaesite. It is one of the more abundant rare-earth metals that mining mostly in China and US.

It can be separated or extracted by ion exchange chromatography and solvent extraction process.


Naturally occurring erbium has six stable isotopes with atomic masses 162, 164, 166, 167, 168, and 170. It also contains 29 synthetic radioactive isotopes that can be synthesized by various artificial nuclear reactions. Most of these radioactive isotopes have half-lives of less than 4 minutes.

The primary radioactive decay mode of these radioactive isotopes is electron capture or beta decay.


The element erbium is a silvery-white, malleable rare earth metal belonging to the lanthanide series in the periodic table. Like other lanthanides, it commonly shows a +3 oxidation number or state.

Symbol Er
Discovery Carl Gustav Mosander in 1843
Name derived from It is named after the mineral Ytterby found in Sweden
Common isotope 68Er166
Oxidation state +3
CAS number 7440-52-0
Periodic properties
Atomic number 68
Relative atomic mass 167.259
Electron per cell 2, 8, 18, 30, 8, 2
Electronic configuration [Xe] 4f12 6s2
Block f-block
Group Lanthanides
Period 6
Physical properties
State at 20 °C Solid
Melting point 1529 °C, 1802 K
Boiling point 2868 °C, 3141 K
Molar heat capacity 28.12 J mol−1 K1
Crystal structure ​​hexagonal close-packed (hcp)
Density 9.07 g/cm3
Heat of fusion 19.90 kJ mol−1
Heat of vaporization 280 kJ mol−1
Atomic properties
Atomic radius (non-bonded) 2.29 Å
Covalent radius 1.77 Å
Electronegativity 1.24 (Pauling scale)
Electron affinity Unknown
Ionization energy (kJ/mol) 1st 2nd 3rd
589.30 1151.07 2194.08

Electron configuration for erbium

The 68 electrons of the erbium atom are distributed in different energy levels to show the following electronic configuration,

Erbium (Er) atomic structure and electron per shell with atomic number, atomic mass, electronic configuration and energy levels of Er atom

Erbium in the periodic table

The rare earth metal erbium is placed in the f-block of the periodic table. It is lanthanide that lies between holmium and thulium.

Erbium element (lanthanide or rare earth metal) symbol Er and position in the periodic table with atomic number, electronic configuration

Chemical properties

It is a reactive metal that is very stable in dry air at ordinary temperatures but slowly dull in humid atmospheres. It burns in the air or oxygen to form erbium oxide Er2O3.
4 Er + 3 O2 → 2 Er2O3

The rare earth metal Er stands far above hydrogen in the electrochemical series. Therefore, it reacts slowly with cold water and rapidly with hot water by the liberation of hydrogen and the formation of erbium hydroxide.
2 Er + 6 H2O → 2 Er(OH)3 + 3 H2

Reactions with acids are more vigorous but the Er does not dissolve in alkalies. It dissolves readily in dilute sulfuric acid to form solutions containing the yellow Er (III) ions.
2 Er + 3 H2SO4 → 2 Er3+ + 3 SO4−2 + 3 H2

It is normally from trihalides with halogens like fluorine, chlorine, bromine, and iodine.
2 Er + 3 X2 (X = F, Cl, Br, I) → 2 ErX3

Facts about erbium

  • It is never found in nature as a free element but found with the minerals of other rare-earth elements.
  • The pure metal was isolated after the discovery of the ion exchange chromatography technique.
  • The approximate price of erbium is $650 per kilogram. After the discovery of advances in ion-exchange chromatography techniques, the price become down.
  • The salts of Er are rose-colored compounds with sharp adsorption spectra in visible, ultraviolet, and infrared light.
  • It does not show any biological role in humans but erbium salts can stimulate metabolism in our bodies.
  • Erbium dope optical fibers can amplify the signals in communication technology.
  • Pure metal is slightly toxic while compounds tend to be non-toxic in nature.

What is erbium used for?

  • It is alloyed with vanadium to lower its hardness and improve its workability.
  • In communication technology, erbium-doped silica glasses are used for making optical fiber.
  • The pink color erbium oxide is used for the coloration of glasses, cubic zirconia, and porcelain.
  • It is used in laser surgery due to the unique wavelength of erbium ions.
  • Salt of Er increases the red blood corpuscle and hemoglobin content in the blood.
  • In nuclear technology, erbium is used for neutron-absorbing material in control rods of nuclear reactors.