Like terbium and ytterbium, erbium is also named after the Swedish town of Ytterby, near which it was discovered. This element does not occur in its pure form in nature, but can be obtained from the mineral monazite. Many erbium compounds are pink in color and are used to color ceramics and glass.
Summary of properties (Er)
| Atomic weight | 167.259(3) |
| Discoverer (year) | Mosander, Carl Gustav (1842) |
| Natural form | metallic solid (hexagonal) |
| Electron configuration | [Xe] 4f 12 6s2 |
| Melting point (ºC) | 1522 |
| Boiling point (ºC) | 2510 |
| Abundance in earth's crust (ppm) | 3.5 |
| Isotope (abundance) | 162Er (0.139), 164Er (1.601), 166Er (33.503), 167Er (22.869), 168Er (26.978), 170Er (14.910) |
| Density g/cm3 | 9.07 |
| Van der Waals radius (pm) | 229 |
| Covalent radius (pm) | 177 |
| Electronegativity (Pauling) | 1.24 |
| Vaporization enthalpy (kJ/mol) | 293.00 |
| Enthalpy of fusion (kJ/mol) | 19.90 |
| Specific heat capacity (J/g·K) at 25ºC and 1 atm | 0.17 |
| Thermal conductivity (W/cm·K) at 25ºC and 1 atm | 0.150 |
| Oxidation state | +3 |
| Electron affinity (eV) | |
| 1st Ionization potential (eV) | 6.1077 |
