65Tb Terbium

Year Discovered


Discovered By

Carl Mosander of Sweden

Biological Rating

Not necessary for life.


Named after the town of Ytterby, Sweden, terbium is a soft, silvery-gray metal that can be cut with a knife. It is a rare lanthanide, and somewhat reactive, slowly reacting with air, but quickly reacting with water and acids. Terbium is used in semi-conductors and lasers. It is also used to produce the green color in color television tubes.

Biological Benefits

Terbium has no known biological use.

Role in Life Processes

No known benefits to life processes in plants and animals.


Terbium is chiefly obtained from monazite, where it occurs as an impurity. It also occurs in cerite, xenotime and gadolinite. Terbium is mined in the USA, China, Russia, Australia, and India.