- (obsolete) A rejected name for hafnium.
1869 July 2, H. C. Sorby, “On jargonium: a new elementary substance associated with zirconium”, in The Chemical News and Journal of Industrial Science:
- These various spectra of jargonium are all of a very marked character, quite unlike those due to any other element in similar conditions.
2014, Marco Fontani, The Lost Elements: The Periodic Table's Shadow Side:
- In the same year as the jargonium announcement, 1869, Arthur Herbert Church (1834–1915) announced the discovery of a new element associated with zircon.
2016, A. Meadows, Science and Controversy: A Biography of Sir Norman Lockyer, Founder, page 59:
- Sorby announced, in 1869, the discovery of a new element – Jargonium – by spectroscopic analysis, but was forced in the following year to withdraw his claim as it was found that the interpretation of the spectrum was more complicated than he had supposed.