The mineral gadolinite - discovered in a quarry near the town of Ytterby, Sweden - has been the source of a great number of rare earth elements discoveries. In 1843, Carl Gustaf Mosander, a Swedish chemist, was able to separate gadolinite into several elements, one of which eventually was named Erbium, after the town near which it was found. Today, erbium is primarily obtained through a solvent extraction processes from clay minerals in China.
Pure erbium metal is soft, malleable and has a bright, silvery, metallic lustre. The metal is fairly stable in air and does not oxidize as rapidly as some of the other rare earth metals.
Applications of Erbium:
- Ceramics and Specialty Glass: Erbium is important as a doping agent in optical fibres, where it enables the fibre to be optically pumped to act as an amplifier for signals passing through it. The same fibres can be used to create lasers. Erbium-based salts are rose-coloured, and the element has sharp absorption spectra bands in visible, ultraviolet and near infrared light and the glass is often used in sunglasses and less expensive jewellery. Erbium is sometimes used as a colourant for glass and porcelain, and also provides the pink color in cubic zirconia.
- Energy: Erbium is used in nuclear technology in neutron-absorbing control rods.
- Materials: Erbium lowers hardness and improves workability when added to vanadium as an alloy. An erbium-nickel alloy has an unusually high specific heat capacity at liquid-helium temperatures and is used in cryocoolers. It is also commonly used as a photographic filter.
- Medical: Erbium is used in a wide variety of dermatology and dental applications. It is commonly used in yttrium aluminum garnet laser crystals for cosmetic procedures and mild to medium depth skin resurfacing.