The Collaborative International Dictionary of English v.0.48:

norium \no"ri*um\, n. [NL.] (Chem.)
   A supposed metal alleged to have been discovered in 1845 by
   the Swedish chemist Swanberg in zircon. After many
   unsuccessful attempts to verify this new element, the element
   named Hafnium (atomic number 72) was discoverd in 1923 by
   D. Coster and G. von Hevesey in the zirconium-containing
   mineral zircon. Hafnium, present at 1 to 5% in many
   zirconium-bearing minerals, but difficult to separate from
   zirconium, is probably the element that gave rise to the
   properties attributed to the hypothetical norium.
   [1913 Webster +PJC]