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Identification of meteorite

  1. Apr 27, 2016 #1

    1oldman2

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    While visiting Wyoming recently I was shown a "rock" that several people have said is a meteorite. My question is how does one identify a meteorite compared to an earth rock. (Hoping you can help me out here Dave) I have included several photos and I can say it definitely shows signs of high heat and while its not magnetic like "load stone" a compass passed over it will swing the needle around. Any opinions would be greatly appreciated, thanks. DSCN1315.JPG DSCN1316.JPG DSCN1317.JPG
     
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  3. Apr 27, 2016 #2

    ProfuselyQuarky

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    Meteorites have certain properties that nearly all of them share. For example, most meteorites are natural magnets. Also, meteorites (especially the ones with a high % of iron) tend to melt as they fly towards Earth. Once they land, they leave these distinct marks (I believe they’re called regmaglipts** or something like that). A meteorite’s composition includes iron and stone (mostly stone). So, people can also do composition, streak, and density tests. If all these points hit the correct mark (which I’m not aware of; it depends probably), the chances of your rock being a meteorite is pretty good, I suppose.

    There are probably more definite tests that I don’t know of so let’s wait for someone else to answer.

    **EDIT: Just looked it up. The correct spelling is regmaglypts
     
  4. Apr 27, 2016 #3

    ProfuselyQuarky

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    The rock in the photo appears looks awfully smooth, though. A meteorite usually looks like this:
    index.jpg
    Maybe there are different types . . .
     
  5. Apr 27, 2016 #4

    1oldman2

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    Yes, that is how I picture an average meteorite. Have you looked over Daves meteorite section? it seems looks alone aren't much of a qualifier as they have a great variety of appearances. This is complicated by the diverse geology in the area the "rock" was found, let me know your take on things as this thread progresses. Here is Daves site, take a look, pretty cool stuff. :smile:
    http://www.sydneystormcity.com/
     
  6. Apr 27, 2016 #5

    ProfuselyQuarky

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    Yes, I've looked at it before! Isn't it great? Perhaps @davenn would be better to answer the question.

    To me, rocks are rocks. And I'd probably be the one fooled if I saw iron pyrite and say that it's gold :P
     
  7. Apr 27, 2016 #6
    "Shows signs of high heat"
    Weathering can give a shiny look to a rock and peculiar features.
    My first guess is that it is an iron oxide nodule.
     
  8. Apr 27, 2016 #7

    1oldman2

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    Thanks, I appreciate the input. Whatever the thing is it has had an interesting existence. :smile:
     
  9. Apr 27, 2016 #8

    ProfuselyQuarky

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    In other words, not a meteorite after all?
     
  10. Apr 27, 2016 #9

    1oldman2

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    A very distinct probability considering how rare those buggers are, This is the best place I could think of for answers so naturally here I am asking. :smile:
    (by the way a little less than two hours until Russia launches from their new facility)
     
  11. Apr 27, 2016 #10
    If rocks could only speak.:smile: the tales they could tell.

    I gave only a first guess as a nay. Doesn't prove anything.
    If I had it in my hand that is what would come to mind in the Sherlock Holmes process of elimination and what remains, even if extradinary ( meterorite, since they are rare compared to other rocks ) has to be the truth. One should consider the nays, along with the yays, just to be fair to the rock.

    Never really said that - appearance can be deceiving one way or the other.
    As you stated there are tests to do along the way to identification.
     
  12. Apr 27, 2016 #11

    Vanadium 50

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    Most identified meteorites are from Antarctica. It's not that more fall there - it's that if you find a rock on top of three miles of ice, chances are it came from the sky.
     
  13. Apr 27, 2016 #12

    1oldman2

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    That is what I understand also, very long odds of this being a meteorite but it is a peculiar piece of rock, somewhere between igneous and metamorphic. If it turned out to be a real meteorite it would probably be considered a relatively large one.
     
  14. Apr 28, 2016 #13

    davenn

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    hmmm a little tricky

    channelled streaks like that are not uncommon in meteorites. I am not going to say "definitely is or isn't

    the closest similar I could find is this meteorite sample ......
    mokiA.jpg

    There is a possibility that it is an iron nodule and I am leaning a little more in that direction

    Dave
     
    Last edited: Apr 28, 2016
  15. Apr 28, 2016 #14

    1oldman2

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    Thanks, could you tell me what tests, chemical analysis or whatever that would be used to determine its true nature ? The area of central Wyoming (near Thermopolis) where it was found is a real "geological jigsaw puzzle" so that's not much of a clue, however odds favor nodule over meteorite.
    Cheers and thanks again. :smile:
     
  16. May 30, 2016 #15
    From what I hear if you scratch a meteorite candidate with a white bathroom ceramic tile and it leaves grey or brown streaks on the rough side (the side of the tile that should face the wall/floor) it is some sort of iron ore. If it leaves no streak it may be a meteorite. This test of course only works if the candidate is in fact magnetic. I heard this from an acquaintance and it may be entirely false. I would assume that you would need to perform a multitude of different tests to be sure. Do you have personal access to the specimen?
     
  17. May 30, 2016 #16

    davenn

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    not a good test as many meteorites are of nickel / iron composition and are magnetic as well ( or at least attracted to a magnet)

    I don't know the geology of that area .... if it has any significant sedimentary deposits related to it, mudstones, clays etc
    Then iron nodules can be readily found in such


    D
     
  18. Jun 1, 2016 #17

    1oldman2

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  19. Jun 3, 2016 #18
    I would check the geology of the area it was found to confirm or not if it was an iron nodule. However, I'm voting for the meteorite. Looks like whatever was in those channels may have melted out on the way down. Of course, what do I know. Get it checked at the nearest university.
     
  20. Jun 4, 2016 #19

    davenn

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    yes, that's what I already commented on


    and going by what I found in the link posted

    it gives good credence to an iron nodule because of the number of large sedimentary basins
    in the region
    without knowing more about the types of sediments, I cannot comment further to if they would support iron nodule formation

    that is a possibility and one I also commented on much earlier in the thread

    but it is also possible that they are fractures caused by the formation of the nodules in the ground ....
    eg .. freeze/thaw fractures caused by moisture within the nodule



    Dave
     
  21. Jun 4, 2016 #20

    1oldman2

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    I'm hoping to get an analysis arranged for some point in July until then it's just a "weird looking rock", I will definitely post the results when I get it figured out. In reading up on meteorites, I understand that the ratios of Iron to nickle (as well as other elements) is a determining factor in whether or not the sample is "extra-terrestrial" however I couldn't find any practical way to visually make an identification without lab testing samples.
    The area the "rock" was found is a conglomeration of just about every geological feature that can be imagined, including plenty of sedimentary and Tertiary fill, not to mention the "worlds largest hot spring". Thanks and I'll keep in touch with the results when I get them. :ok:
     
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