Erbium is known as a chemical compound grouped with the lanthanides in the periodic table, it has an atomic number of 68, its atomic weight is equivalent to 167.2, and it is represented by the acronym Er, only six isotopes are used that are relatively stable, this element is one of the most stable when it is in constant contact with air, therefore its oxidation is a little slower compared to other rare metals, like the other elements it has a color silver accompanied by a permanent shine, it is characterized by being one of the softest metals and is extremely malleable, it presents magnetism by iron property that is modified at a certain low temperature, however if it is in extreme cold its ferromagnetic capacity increases significant way.

The origin of the name Erbium is shared with the chemical element Terbium, both come from the word Ytterby, this being the name of a Swedish city where the discoverer of both elements called Carl Gustaf Mosander resided, he separated the salt from “ityria” Obtaining three compounds which he called ititira, erbium and terbium, he chose those names not only because it was his hometown, but also because it was the region in which great sources of these elements were found. According to the similarity of the nomenclature of both metals they were confused for the years 1843, the element erbium was assigned the name of terbium and vice versa, it was not until the year 1877 that the error in the names for both chemical compounds was deduced, in the same year it was ruled that despite their similarities, erbium and terbium are totally different metals, so they behave differently at different established reactions.

There are various applications for erbium metal, among which can be listed, photographic filter material to change the color of the image, due to its resistance it is very useful in the area of ​​metallurgy, due to its stability it has the ability to absorb neutrons and for this reason it is used in the nuclear field, according to the fact that when it is oxidized it has a pink pigmentation, it is used as a colorant for glass and enamels for porcelain pieces.