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chris1987

suspect meteorite

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Nope, sorry.

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Any other opinions?

What do you look for in photos that makes you sure it is or isn't a meteorite?  What's wrong with this rock?

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OK, but I just don't know how you (and many others usually, but you are the only one to respond here) can make such definitive statements from a photo and no other info.  Is it just because 99 times out of 100 when people post photos of suspect meteorites they turn out not to be, so you (and most others) are just playing the odds, or is there something that is so obvious about meteorites that they are easy to discriminate from just a single photo?  What specifically are you looking for that is missing here?  What about it makes it look so clearly like iron ore? To educate myself I've looked at hundreds of meteorite photos and quite a few meteorites in person and have seen that there is a lot of variation in appearance even among ordinary chondrites.  I'm not trying to pick a fight here or question your expertise, it's just that it doesn't seem that obvious to me.
 

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RB, 

There are a lot of meteorites out there but this just doesn't look like the typical type of meteorite and has more characteristics of a terrestrial rock. Granted, you're probably saying, "Well then what does a typical one look like?" One has to remember that 80% of the falls on Earth are of the ordinary chondrite type of meteorite, stony that is.  They have characteristics of regmaglypts, or the so called "thumb-prints" on them from ablation.  Most meteorites don't have vesicles or small, once air pockets, in them either.  Another thing to look for is stratification within the rock itself. If you see layers, probably not a meteorite or any type of other rocks mixed into it.  A streak test, magnet test, nickel test, and chondrules are good other indicators to see if its a meteorite.  Granted, there are some meteorites people have found that I would have thrown back, because they didn't fit the "normal" rules of what one should look like and turned out to be one (most lunars because they are the impact-melt breccia type)  The Earth is pretty hard on meteorites, especially if its in water.  Remember, that space is a vacuum and the atmosphere on Earth breaks down the composition of the meteorite once it enters it and fast.  The SW is such a great preserver of meteorites due to the arid climate, and fact they are preserved so well.  One of my typical characteristics I look for is the "chocolate" or "poop brown" color, and appears to be common in a lot of the meteorites here is the SW.  

Hope this helps to explain some of what Mike may be saying....just my two cents.

 

Jason   

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21 hours ago, Mikestang said:

It looks clearly to be terrestrial iron ore of sorts, had no characteristics of a meteorite.  If you file a window and do a streak test I'd wager it comes up red/brown.

http://meteorites.wustl.edu/meteorwrongs/meteorwrongs.htm

Mike, I had some obvious meteorites fail the strike test as they streaked a reddish brown colour. It wasn't until I did some investigating and came across another post on here in which you replied saying you didn't fully trust this test. This actually gave me hope and probably saved me from throwing away a few that were skeptical. My assumption is that if they are weathered condritres with oxidizing, they will leave a streak, unlike a freshy which has not oxidized yet. What are your thoughts on this? From the countless photos I have researched, it seems pretty apparent that freshly fallen meteorites are whitish/grey on the inside but after some time on earth, the inside color seems to change? I'm just assuming this but would be great if you can clarify. Now a little off topic, I read that a good way to determine if it's a meteorite is if the interior is a different colour than the exterior...but I wouldn't consider this a good test unless it has freshly fallen. Seems to me that most weathered chondrites hold the same color inside and out after having oxidized and lost their fusion crust. Is this true? 

The one thing that seemed to be the real winner in regards to determining a chondrite is the presence of chondrules. Are chondrules present in all ordinary chondrites or do some lack these entirely?? Are chondrules present on every cut surface or would you maybe have to grind a little deeper to reveal them? (Probably a stupid question but while we are on the topic about meteorite tests...) ?

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RB,

Here is another page that some good info on what is and is not a Meteorite, with some example. Again, not all the rules apply to every rock. But most do. 

http://meteorites.wustl.edu/realities.htm

Jason

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Redbeard -

No, I am not playing the odds in the way you suggest.  Imagine you had never seen a lemon or an orange before, but you had an idea what they looked like.  Now say lemons are super super rare, but oranges are everywhere.  How would you know how to tell them apart?  They are both fruits, they look very similar, similar colors, similar rind, similar skin texture... it's only through experience and exposure to lemons and oranges over and over that you come to know the difference between the two at a glance.  With meteorites it is much the same.  I've been lucky enough to study meteorites since I was a kid and I have a pretty good track record at picking them out in a line up.  Granted there will always be odd balls, but they are rare of the rare, few and far between.  Meteorites are rare, so when we talk about a rare something that's already rare, chances are none of us will see them in our life times, so as far as odds go that's about the only place I play them.

 

munroney -

Yes, chondrules are present in all chondrites, ordinary or otherwise, thus their name chondrites.

A very oxidized meteorite will streak reddish because of the iron oxides that are present in it, so no it is not a definitive test by any means.  But in the case of a rock such as this, which does not appear to be a meteorite of any sort, a red streak would serve to confirm that observation.

Terrestrial rocks often have skins of oxidation form on them, or weathering layers, and that can cause the outside to be different than the inside, so that's not really a meteorite indicator.  And several meteorites that are just fragments of old, broken up stones, like Yelland Dry Lake for example, will look the same outside an inside (and in the case of Yelland will have basically 0 visible chondrules and looks just like a rock to most people).  For example, below is an in-situ photo one of my hundreds of finds from a known strewn field in Nevada, the fragments there are very similar to Yelland.  The purple brown rock (poop color, like Jason said) is a meteorite fragment, the black rock is terrestrial.  It takes a lot of experience to spot these fragments in the midst of terrestrial rocks, but when you know what you're looking for they stick out like a sore thumb.

 

Chondrules are readily visible in type 3 and 4 chondrites, typically you can even see them through the fusion crust or on the outer surface of a broken face.  Chondrules will be much harder to spot on a type 5 chondrite, and almost nonexistent on a type 6.  Here is a useful table regarding chondrite petrologic types:

9007569.jpg

tn1-037.jpg

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If you have any color vision deficiencies  it will be nearly impossible to spot by color....I think the one next to the scale is the meteorite...mostly because the other one looks like ironstone...I would not bet on my answer without seeing and touching them...

fred

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Yes, Fred, the one lower right is the meteorite, and that photo is just how I found it, resting against its neighbor.

For fun, here's a few more from the same locale found next to terrestrial rocks.

dfummw.jpg

dbi4ue.jpg

2mnrntg.jpg

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Mike,

Like I say, "Poop brown...", LoL. :4chsmu1:

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The stone I posted actually is a meteorite which makes my point of how hard they can be to ID just from a photo.  Although it definitely meets the "poop brown" criterion.:yesss: It is not even a particularly odd stone, just another ordinary chondrite.  If you saw it in person you would have little doubt.  On the other hand I have seen other ordinary chondrites that even when in my hand I wasn't totally convinced. 

I only engaged in this thread because I think people are often too quick to judge a photo posted by a "newbie" as not being of a meteorite.  In this case I have seen meteorites that look similar to the photos posted by the OP, my photo being one example.  That's why I suggested he cut his rocks open.  Seeing chondrules would pretty well settle it for 85% of meteorites (ordinary chondrites).  If there were no chondrules or there were something like quartz crystals inside then he could be pretty sure it wasn't a meteorite.  Sure it is unlikely that they are meteorites but the photos alone are not good enough to be sure, but maybe there is something conclusive that I missed.  If you look at the thousands of actual meteorite photos on the internet you will find lots of them are pretty poor photos and not particularly diagnostic.  I know because I have and I'm constantly frustrated by the poor lighting and detail many photos have. 

Personally, unless there is something fairly obvious to tell me it definitely isn't a meteorite, like some of the things mentioned in posts above, I like to be a little more cautious about making a conclusive determination either way when looking at a photo on the internet and without additional info.  Why not entertain the possibility and have the OP take the next step and cut it open?

 

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8 minutes ago, Redbeard said:

The stone I posted actually is a meteorite which makes my point of how hard they can be to ID just from a photo.  

 

Darn, I was actually going to suggest it was, but my only assumption would have been from the dark red/maroon colour blended into the black. Meteorites do not always have regmaglypts, only if they are oriented. My research has shown me so many different sizes, shapes, and especially colours in meteorites. I found one that was half buried and went from a light red to almost orange-yellow...also seen bright red, dark red, steak and cheese-poo brown, Vegetarian-poo brown, black, purple-ish and everything Inbetween. It really all depends on the environment and how badly it's been weathered. 

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It is my humble opinion that is a rock from earth. I have collected many meteorwrongs and sent 10 or 12 suspects to university for testing, and all of them not meteorites.It's a tough field and if your skin is too thin you might not stick with it long. My reason your sample is not a meteorite is the surface is not doing it for me. As others will tell you it takes time, but after awhile you will develop a better eye!

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I'd say yes, but hard to tell until you get to the inside. Can you file a window and snap a close up pic? It obviously has lots of metals, but let's see those chondrules ?

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3 hours ago, hardtimehermit said:

It is my humble opinion that is a rock from earth. I have collected many meteorwrongs and sent 10 or 12 suspects to university for testing, and all of them not meteorites.It's a tough field and if your skin is too thin you might not stick with it long. My reason your sample is not a meteorite is the surface is not doing it for me. As others will tell you it takes time, but after awhile you will develop a better eye!

which one are you refering too?

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Hi Chris, i was talking about your most recent photo.

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1 hour ago, hardtimehermit said:

Hi Chris, i was talking about your most recent photo.

Ok should i throw it in the river or do you want me to send it you? Maybe a regular rock collecter might want it :)

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got a window / streak test just gotta get some finer sand paper to finish of the window. But this is what i have for now

WP_20160724_15_45_21_Pro.jpg

WP_20160724_16_26_47_Pro (2).jpg

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On 7/21/2016 at 6:03 PM, Redbeard said:

The stone I posted actually is a meteorite

 

How do you know this, has it been classified?  Do you have other pictures?

I do not appreciate being messed with, if you knew it was a meteorite (and it's been confirmed) then you should say that when you first post the picture and explain it.  Posting pictures like that just trying to fool people is kinda lame.  I know there are meteorites out there that just a picture isn't going to be able to id them, but if someone posts a picture and asks for an opinion that's what they get from me.

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10 hours ago, Mikestang said:

  I know there are meteorites out there that just a picture isn't going to be able to id them, but if someone posts a picture and asks for an opinion that's what they get from me.

I think that was the point he was trying to make. Ultimately there's 3 answers you could give him. Yes, no, and maybe. If you needed more pics or evidence to determine your opinion, then the answer should have been "maybe".  Let's say that he didn't know, and he tried the streak test and it came up a red/brown colour..this still doesn't rule out the possibility of it being a meteorite. Coming from someone who clearly has a lot of experience and knowledge about meteorites and meteorwrongs, i think you could have dug a little deeper for more evidence to back your opinion. If you are the expert you portray yourself to be, then there should be no "fooling" you.

 Anyways, there's a really cool formula to access situations like this: 

  • Ask a Question
  • Do Background Research
  • Construct a Hypothesis
  • Test Your Hypothesis by Doing an Experiment
  • Analyze Your Data and Draw a Conclusion
  • Communicate Your Results

 

 

 

 

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:pop:

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