Where was the rare earth element terbium first discovered?

Terbium was discovered in 1843 by the Swedish chemist Carl Gustaf Mosander. The mineral source came from Ytterby, a village near Stockholm that became famous in chemistry because several elements were named after it. Terbium was one of the rare earth elements extracted from complex mineral mixtures from that site. The discovery is part of the remarkable history of Ytterby, one of the most element-rich places on Earth.