Terbium is a rare earth element and it belongs to the lanthanide series of the periodic table. It is positioned in the f-block and 6th period. Chemically, it is represented with the symbol Tb. The credit for discovering this chemical element goes to famous Swedish chemist Carl Gustaf Mosander who discovered it in the year 1843. It cannot be found in the form of a free element in nature. The term rare earth element does not mean that terbium is rarely found in the earth but it was quite difficult to purify this metallic element. It is found in many minerals like monazite, gadolinite, xenotime, cerite and so on. Let us find out more terbium facts related to its characteristics in the following section.