Webster's Revised Unabridged Dictionary · 1913

(Chemistry) 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 discovered 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.