from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A magnetic form of iron sulfide, Fe2+Fe3+2S4, analogous to magnetite, produced by microorganisms and found in lake sediments; Note: half the iron ions are ferrous and half ferric.


from Wiktionary, Creative Commons Attribution/Share-Alike License

From Joseph W. Greig, American mineralogist


  • These mineral crystals were identified as magnetite, pyrrhotite, and greigite.

    The Case for Mars

  • This evidence includes the oxygen isotope ratio data, the presence of greigite within the carbonates, and the presence of organic molecules—all would be destroyed or degraded if heated to 450°C.

    The Case for Mars

  • Magnetosomes are composed of single-domain magnetic nanocrystals of magnetite or greigite (35 nm to 120 nm long) embedded in biological membranes.

    PLoS ONE Alerts: New Articles

  • Thomas-Keprta’s doubts fell away as she positively identified minute grains of the mineral greigite, which, in the size range she discovered, is more often than not produced by bacteria, at least here on Earth.

    The Case for Mars


Log in or sign up to get involved in the conversation. It's quick and easy.