Element category: lanthanide Erbium is a soft, malleable, lustrous, silvery rare earth metals belonging to the lanthanide group. It is stable in air, reacts very slowly with water and oxygen, and dissolves in acids. Erbium is one of the rare earth elements among Lanthanide series. Pure Erbium metal is malleable, soft and fairly stable in air. It oxidizes slower than some other rare-earth metals. Common uses of Erbium are as a photographic filter and as a metallurgical additive. Erbium can also be used in nuclear technology. When alloyed with vanadium, erbium lowers hardness and improves workability. Erbium-doped glasses or crystals can be used as optical amplification media. Erbium also has specialized uses in medical applications. Erbium Oxide is widely used as dopant in making optical fibre and amplifier. Erbium is commonly used as a photographic filter. It is also used to alloy with metals to lower the hardness and improve the workability. Erbium isotopes are good neutron absorbers so they are used in nuclear reactor control rods. Erbium compounds are rose-colored, and have excellent absorption spectra bands in visible light, ultraviolet, near infrared. Erbium oxide (Er2O3, erbia) has a pink color, and is often used in infrared absorbing glass or coloring glasses.