Erbium is a chemical element with the symbol Er and atomic number 68. It is part of the lanthanide series and is known for its pink-colored compounds. Erbium is primarily used in various applications, including fiber optics, lasers, and as a dopant in certain materials to enhance their properties. This element is found in nature in minerals such as gadolinite and monazite. Erbium's unique properties make it valuable in the technology sector, particularly in telecommunications, where it helps amplify signals in fiber optic cables.