Chemical Element: thulium

(Modern Latin: from Greek, Thule, the Greek name for land north of Britain or for Scandinavia; rare earth)

Chemical-Element Information

Symbol: Tm
Atomic number: 69
Year discovered: 1879

Discovered by: Per Teodor Cleve (1840-1905), a Swedish chemist.


  • Per Teodor Cleve of Sweden discovered holmium, in 1879, while working on erbia earth (erbium oxide).
  • Thulium oxide (holmia) was present as an impurity in erbia.
  • The element is named after Thule, the ancient name for Scandinavia.
  • Greek geographers thought Thule was the most northerly region of the habitable world.
  • The metal is readily oxidized by air or by water.

Name in other languages:

French: thulium

German: Thulium

Italian: tulio

Spanish: tulio


Information about other elements may be seen at this Chemical Elements List.

A special unit about words that include chemo-, chem- may be seen here.