An Etymological Dictionary of Astronomy and Astrophysics

A metallic → chemical element occurring abundantly in combined forms and used alloyed in a wide range of important tools and structural materials; symbol Fe. → Atomic number 26; → atomic weight 55.845; → melting point about 1,535°C; → boiling point about 2,750°C; → specific gravity 7.87 at 20°C; → valence +2, +3, +4, or +6.

Iron is of critical importance to life, i.e. plants, humans, and animals. It occurs in hemoglobin, a molecule that carries → oxygen from the lungs to the tissues and then transports → carbon dioxide (CO₂) back from the tissues to the lungs.

Iron has the highest nuclear → binding energy of all elements, and is therefore the most stable element. It is synthesized in → massive stars, and its occurrence ends the process of → thermonuclear reaction in stars. The resulting energy crisis leads to the destruction of the star through a → supernova explosion. It has several → radioactive isotopes with half-lives from 6 min (⁶¹Fe) to about 3 x 10⁵ years (⁶⁰Fe).

Etymology (EN): Iron, from O.E. isærn, from P.Gmc. *isarnan (cf. O.S. isarn, O.N. isarn, M.Du. iser, O.H.G. isarn, Ger. Eisen) “holy metal” or “strong metal,” probably an early borrowing of Celt. *isarnon (cf. O.Ir. iarn, Welsh haiarn), from PIE *is-(e)ro- “powerful, holy,” from PIE *eis “strong” (cf. Skt. isirah “vigorous, strong,” Gk. ieros “strong”).

The chemical symbol Fe, from L. ferrum “iron.”

Etymology (PE): Âhan, Kurd. âsan, Mid.Pers. âhan; Av. aiianhaēna- “made of metal,” from aiiah- “metal;” cf. Skt. áyas- “iron, metal;”  L. aes “brass;” Goth. aiz “bronze;” O.H.G. ēr “ore” (Ger. Erz “oar”); O.E. ora “ore, unworked metal,” ar “brass, copper, bronze.”