ELEMENTLE

Element 68 · Lanthanide

Erbium

Period 6

Erbium is a chemical element in the lanthanide series, with symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements on Earth. As such, it is a rare earth element which is associated with several other rare elements in the mineral gadolinite from Ytterby in Sweden, where yttrium, ytterbium, and terbium were discovered.

Three reasons Erbium stands out

  1. 1

    Used in lasers and fiber optics.

  2. 2

    Fibre-optic amplifiers doped with this element made the modern internet possible by boosting signals across long distances.

  3. 3

    Its compounds give a delicate pink tint to glass, crystals, and certain gemstones.

The pink ion that strengthens the internet

Erbium ions can absorb pump-laser energy and release it at wavelengths used in fiber-optic communication. Erbium-doped amplifiers boost signals directly as light, avoiding repeated electrical conversion across oceans. The same ions give glass and crystals a characteristic delicate pink color.

Erbium at a glance
Atomic number / protons68
SymbolEr
Family (Elementle)Lanthanide
Classification (PubChem)Lanthanide
Period6
GroupLanthanide / actinide series
Atomic mass (u)167.26
Standard stateSolid
Electron configuration[Xe]6s2 4f12
Reported oxidation states+3
Electronegativity (Pauling)1.24
Atomic radius (pm)235
First ionization energy (eV)6.108
Electron affinity (eV)Not available
Density (g/cm³)9.07
Melting point1802 K (1,528.85 °C)
Boiling point3141 K (2,867.85 °C)
Discovery (PubChem)1843

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Erbium · Erbium on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.