Discovered in: 1879

Discovered by: Per Theodore Cleve of Sweden

Description: Named from Thule, an ancient name for Scandinavia, thulium is a soft, silvery-gray metal, soft enough to be cut with a knife. It is the rarest of the lanthanide metals, excluding radioactive promethium. Thulium is an active metal, reacting with air, water and acids. When thulium is irradiated, it gives off X-rays. Consequently, it is used in portable X-ray machines that do not need external power. It is also used to produce magnetic ceramics and alloys with other metals. It serves as a medical isotope.

Biological Rating: No known benefit for life processes in plants and animals.

Biological Benefits: Thulium has no known biological use. It does act to stimulate the metabolism.

Percentage Amount in the Human Body: 0 %

Obtained from: Thulium is chiefly obtained from bastnasite and monazite, where it occurs as an impurity. It is mined in the USA, China, Russia, Australia, and India.