We are delighted to report a new porphyritic olivine (PO) type micrometeorite with large olivine crystals in glass and a size of approximately 0.3 mm.
Due to impurities composed of the iron cation, Fe3+, this spectacular urban micrometeorite has a slightly brownish color. Its shape lacks a typical aerodynamic form since the surface tension did not finish its job of creating a sphere. This indicates a relatively low peak temperature during atmospheric entry. Note also the open vesicle, which suggests the degassing of volatile elements was not completed.
On the surface there are a couple of large nickel-iron/sulfide chunks, so differentiation has not gathered the denser elements to a metal core. Again, this is due to the low peak temperature during atmospheric entry.
The unusual feature of NMM 3125 is its small chromites; The angular shiny crystals sprinkled over the surface. This is one of the many newly discovered, and still not described phenomena on fresh micrometeorites.
Jon Larsen & Jan Braly Kihle