Thulium

The discovery of the silvery-white 69^th element was made in 1879 in Sweden. One of the less abundant rare earth elements, thulium must be protected from moisture, but it is quite stable in air.

Thulium is difficult to separate from the other elements with which it is associated in nature. Its scarcity limits its applications to research. However, the medical, mechanical and electronics industries make use of thulium.

The bombardment of thulium-169 in nuclear reactors produces thulium for use as a portable source of X-rays employed in medical and dental diagnosis as well as detection of defects in physically inaccessible mechanical and electronic components. Today, thulium has applications in microwave technology as it is a component of the magnetic and ceramic materials found in microwave equipment.