Thulium ( Tm)
Thulium ( Tm)
Discovered in 1879, thulium occurs in a number of minerals, including monazite. It is the least abundant of the rare earth elements and as rare as silver, gold, or cadmium.
Thulium is silver-gray, soft, malleable, ductile, and can be cut with a knife. Twenty-five isotopes are known, and natural thulium is stable.
Relatively expensive, thulium has limited applications. It may be useful as a radiation source for portable X-ray equipment or as an energy source. Natural thulium may be useful in ceramic magnetic materials or microwave equipment.