Dark Iron it sounds like something drawf's mine in a fantasy game, not from something out of astrophysics but Mirror Matter Iron Nuclei is what Robert Foot claims. the CDMS II detector has discovered. Combined with his sighting of mirror electrons in the CDMS detector, and candidate of mirror oxygen atoms, in the solid DAMA results. Thing are looking up for mirror matter as a theory of dark matter.
The Theory of Mirror Matter, is just like in Alice in the looking glass, another physical matter which the same sort of atoms and proton and neutrons, and it own mirror-light, that is invisible to us. Ordinary Matter is left-handed with respect to some nuclear interactions. Mirror Matter would be right-handed with respect to it. Combining the two result a world that has regained its mirror symmetry. Ordinary light and mirror light might mix slightly, the only free parameter in Robert Foots, et al, theory, and each of this three detect results, is described by the same amount, about 1 part per billion, an amount weak enough to prevent mirror matter upsetting the big bang theory and making it quite invisible to telescopes.
Despite only a few researcher working on it, the Mirror Matter theory has impressively worked out, with results for its effects on large structure formulation, the early big bang, and how it forms a halo in the galaxy. The Mirror Matter, with all types of atoms, but a lack of hydrogen fuel for its stars, is thermalised as a plasma supported by the heat of regular mirror-supernova and perhaps accretion into the central black-hole of the galaxy.
If there is ever proof of mirror matter, Perhaps one day, physicists will amass enough mirror matter to create a mirror telescope and look out to a complete different alien sky, full of supernova relics and dense clouds that hold the other four-fifths the matter in the universe.