58Fe

58Fe is a stable isotope of iron with atomic number 26 and mass number 58. It is one of the four stable iron isotopes, alongside 54Fe, 56Fe, and 57Fe. In nature, 58Fe accounts for about 0.28% of iron atoms and occurs in trace amounts in iron-bearing minerals and alloys.

58Fe is an even-even nucleus with a ground-state spin of 0+. It does not undergo radioactive decay and is considered stable on cosmological timescales. Its binding energy per nucleon is similar to that of the more abundant 56Fe, reflecting its position near the peak of nuclear binding energy on the chart of nuclides.

58Fe is produced in stars by neutron capture and explosive nucleosynthesis. In the iron-peak region, it arises from successive neutron captures on neighboring iron isotopes (notably 57Fe) during s-process and in explosive silicon burning in supernovae. In the solar system, the isotopic composition of iron includes 58Fe at its natural abundance, contributing to the overall iron inventory of Earth.

Because it is stable, 58Fe is detected and quantified by mass spectrometry in isotopic studies of rocks, meteorites, and iron alloys. Isotopic ratios involving 58Fe are used to investigate nucleosynthetic processes and the chemical evolution of the solar system. It is less commonly used for spectroscopic techniques compared with 57Fe.