Mystery rock found in back yard


Alan Graham says:

I was digging holes in the yard to plant bamboo when I hit something very hard and big. My two foot wide hole became four feet just to get it out. About the size of a basketball, but was almost impossible to lift. I sprayed it down with water and found some rust colors and assumed it had some iron in it. Magnet proved that assumption, but I was curious as to what type of rock this might be as it has all sorts of interesting markings as well.

BTW...I found another rock [shown above], I'm assuming a part of this one, next to it and included photos of it as well.

Mystery rock found in back yard


  1. I thought most meteorites were small, like the little tiny ones you find in Alaska and whatnot. If it is a meteorite id say its on the pretty dang big side.

  2. I would absolutely guess meteorite. It looks extremely similar to the picture gladeye provided and although it’s true they don’t often burn up that small, it’s been known to happen a time or two.

  3. @gladeye
    I don’t know that I would consider “about the size of a basketball” to be that small. If it were a meteorite, I think one that size would be worth a fair amount of money. But I’m not expert on any of this either ;-)

    1. I didn’t state my thought clearly. I didn’t mean that the meteorite couldn’y be that small. Meteorites can be any size. There are things called micrometeorites. I meant that the holes/indents aren’t usually that small.

  4. So who would you call to positively ID this as a meteorite? If it is one, you could probably get some serious money for it.

    1. You don’t want to plant bamboo! You’ll never be able to get rid of it!

      That is an evil and malicious lie! There are running bamboos, which take over, and clumping bamboos, which stay right where you put them.

  5. Any reason to not suspect it is man made, I am guessing slaggy iron and 150 years would do this. Do you live in the east where iron artifacts would be more common? Perhaps you are living near an old iron smelter. The round ‘rock’ does make me suspect a meteor.

  6. You might want to check the historical use of the land. That picture looks similar enough to slag from old iron bloomeries that I’ve encountered on archaeological sites. If they were really inefficient in refining, they would have enough iron in the slag left to still be rather magnetic. As iron refining industries weren’t necessarily rare, I would even put money on this explanation over meteorites.

    At the same time, it would be REALLY REALLY COOL if it came from space. :D

  7. The vesicular texture is indicative of rapid cooling of a gas saturated magma/slag. The iron rich composition in conjunction with this texture almost surely indicates an anthropogenic origin – likely iron rich slag. Almost certainly not a meteorite. As a geology professor I get questions like this all the time. I have seen genuine meteorites, but most of the backyard finds are slag or some other terrestrial rock.

    1. Eh…if it were lava rock, it’d weigh next to nothing for its size. I’d guess slag of some sort too. In Portland, Oregon, though?

  8. It looks like slag, a by product of iron smelting, also found where there have been either glassworks or potteries or brickworks.
    In some areas, lumps like this were put in gardens as decorative features, broken slag was used in farmland as fertiliser (rich in minerals), and as material for roadmaking.
    Although the meteorite hypothesis sounsd cooler than ‘industrial by-product’!

    1. Although the meteorite hypothesis sounsd cooler than ‘industrial by-product’!

      Why choose between the two? From looking at it, I’d say that it’s obviously and industrial by-product, but of extra-terrestrial origin. My guess is that it originated in an iron-age-analog civilization on a planet orbiting Sirius.

      But that’s the easy part. The real mystery is how it ended up here!

  9. I’m guessing it’s a piece of weathered slag.

    It’s definitely not “too small.” In fact, in the unlikely event it is a meteorite, it would likely be worth quite a lot of money to collectors.

    Contact a university with a meteoritic department.

  10. Could be a meteorite, but could also just be slag. Ferrous slag would be composed of iron, iron oxide, and silicates. The relatively regular shape of both of these chunks makes me think they’re the result of a man-made process. Would be nice to know where (geographically) it was found.

    If the slag is ferrous, then it’s likely the result of copper smelting, as slag from steel making generally has a low iron content – the idea’s to keep the iron and smelt out the impurities.

  11. If you want to check some more, test for Nickel. It’s common in meteorites, and many people are allergic to it so you can find testing kits in pharmacies.

  12. We had big chunks of that in the garden of a house we lived in when I was at school. It was on a street built over a worked out coal mine (Paragon Deep Pit if you fancy googling it), just up the road from a rusting and closed down smelting works and a block away from a defunct shunting yard. Lovely place, so it was. All covered in houses now though.

    Anyway, slag gets my vote as well.

  13. Have you checked it with geiger counter? Maybe there’s still some radioactivity. If it’s heavy it means it could carry a lot of it.

  14. I’m a geologist, and the holes, high density, iron richness and straight edges say it’s a lump of Slag. We showed the students some last month in the practical class. Pretty neat, but not a meteorite – sorry!

  15. This is not a meteorite, period. Get the dollar signs out of your eyes. Anyone who knows meteorites could tell you that in a glance. (While I don’t claim to be an “expert” on meteorites, if you google my name along with the word “meteorites” you’ll see that I’m not unfamiliar with them either.)

    Here’s a site to visit, though:

  16. I’ve done archaeology in a lot of urban and suburban areas, and pull up stuff like this all the time in the top layers. I’m voting for slag.

  17. I’m fairly convinced it’s slag as well. I used to live in a city next to a copper mine where the roadsides were littered with the stuff. It’s fairly cool material – it can be moulded into bricks and used for buildings, with a very special sheen.

  18. It’s a piece of petrified atlantian satellite debris. (If you google my name and atlantis, you’ll see that i’m not familiar with this stuff.)

  19. It could be some sort of igneous rock, but a little context of where it was found would help. Do you live inside an active volcano, or near an undersea vent?

  20. It looks as though it could be an igneous rock. Where in the states are you located? It could also be slag.

  21. No meteor is going to leave a hunk like that. The geologist says slag on your photo stream, guess he’s right.

    Far more important, it cannot be said enough, is THINK before you plant bamboo. I won’t say don’t plant it, because I love bamboo, but I can tell you our little patch became a large very high, beautifully swaying in the wind plot of bamboo. And it is taking over the neighbor’s yard but we don’t like them anyway. You should think of these things firs, and then happily plant!
    1. You will end up having an extremely tenuous, impossible to extract alien invader (unless you are in Japan or China, then not alien). They make runners underground far away and you get a wood network underground.
    2. They will stick sharp shoots up out of the ground and someone can get hurt if they fall on them.
    3. Don’t plant somewhere that will force you to trim branches. Because (at least for our 1-2 inch diameter ones) they are very springy so it is quite dangerous. My Mom had it spring back and almost cut her face.
    4. Think carefully about what species you want. You are going to have a lot of bamboo, I wished we had planted an edible variety and one with enough diameter to make cups and stuff out of it. After years ours still are small diameter. However, the bamboo is the only visible survivor of a project 30 years ago to try and build a Japanese garden in our backyard (New Jersey), I’d say it will outlast almost any kind of landscaping catastrophe, financial meltdown, etc. Extremely relaxing to watch the beautiful, tall stand of bamboo swaying in the wind.
    5. It might be good to hold lose mountain soil together but otherwise do you really want to fight this only-slightly-more-civilized-than-kudzu warrior of the plant kingdom for the rest of your life? Yes it is cool though. And as far as I know, doesn’t hurt pollen sufferers.
    6. If you are willing to try and replicate that awesome green Korean bamboo liquor called Chamisul, I’ll move in and help!!

    Matt R.

  22. Meteoric iron. Either that, or slag from iron production, but since he mentions no such history I’ll go with the space option.

  23. As cool as it would be to have a space rock in your backyard, here’s a chance to visit your local historical society to learn what sort of foundry or what have you, was located where your yard now is. And that’s pretty neato too, ain’t it?

    And besides, the whole dang planet is kind of a big space rock.

  24. It is a meteorite.
    Hit it with a spade to open it up.

    If it’s anything like the one I came to earth in.

  25. I go with slag as well though my dad told me about something they called “clunkers” (I see someone mentioned Clinker above) that was a by-product of burning coal. Essentially the impurities don’t burn and consolidate at some spot in the furnace to be fished out later.

  26. People, people, people! Slow down a second. Look at the overall shape of the object. It’s OBVIOUSLY a perfect specimen of a fossilized Neanderbob, a long-extinct ancestor of Spongebob Squarepants.

  27. Yeah, I’m afraid I might have to side with terrestrial origin as well, unless it is somehow proven otherwise.

    Slag iron, common in things like lawn mower engine blocks and the like, is foamy and full of impurities, and tends to age a bit like this. Might have been touched by fire at some point, but rust would be enough to bring out that bubbly texture.

    But have someone who could iD a meteorite have a look.

  28. This looks like lots of the very old volcanic material found in the Stikine Volcano belt (Canada, Yukon), if I am correct, not being at all educated in this, according to my books the stuff I find here was formed under water.

    Where geographically was it found ?

  29. I am the foremost authority on meteorites in my household, and I can assure you that what you have here is definitely not bamboo.

  30. Thats pure evil! Don’t touch it!
    It does look a bit like old slag. Although slag ideally won’t have much iron in it, because the entire point of making slag is to separate the impurities FROM the iron.

  31. Is anyone else seeing Jesus?
    I think this chick named Mary had a thing for him.
    As for the rock, slag.

  32. It looks like my wife’s meatloaf. Did you break any teeth when you tried to eat it? That’s a sure sign.

Comments are closed.