Identification help!

[alspanther]

Hi there,
Found this recently while out metal detecting, gave off a high-pitched signal. It was covered in moss and when I cleaned this off I found it had a slight magnetic pull, just strong enough to hold the magnet shown in the pics. I ground a piece off the corner as suggested on the web but I'm still not sure what I'm looking for. It does have rounded edges and what looks like flow lines and it's pretty heavy (15kg) and approx. 31cm in length. Would like to hear opinions on what you think this is and whether or not it's a meteorite! Thanks.

[msg-meteorites]

Hi, thanks for posting and thanks for showing us photos that are in focus, normalyl we just see very blurry photos that are very hard to identify! Unfortunately i don't think it looks meteoritic to me, the texture and pumice like texture is all wrong. Are there any metallic flecks in it at all?

Anyone else have any ideas?

Cheers

Martin

[alspanther]

Thanks for the reply, there are small shiny specks on the surface but it's hard to tell if these are metal or crystalline!

[Barwellian]

Not a typical looking meteorite if it is one...most likely volcanic or industrial slag because of the many vesicles, but then have been some unusual meteorites come to light over the years...as Martin says it might be good to look for metallic flecks. The best test would be to have it probed for Nickel...if it has nickel then you might be on to a winner....have you got a local university that might be able to help with that?

Graham

[Kieron]

Sorry, but I don't think this is a meteorite. If there are shiny specks on the surface they must be crystalline - metal at the surface would be rusted/oxidised. Also, the windowed area looks too much like the surface of the rock - I would have expected some sort of weathered crust.

There are many kinds of terrestrial rock that contain enough iron to give a signal with a metal detector or to be attracted to a magnet - I have found dozens of them while searching for meteorites at Ashdon and elsewhere. Having said that, it is always worth investigating those 'hot rocks' and I hope that if you get any more you will consider sharing them here.


Regards, Kieron

[alspanther]

Thank you for responding, I don't have a university nearby as I live in the wilds of west wales so that's why I am gathering opinions first!
Whatever is making the metal detector beep, I don't think it's iron as it's too high pitched, similar to aluminium or silver.
If I find anything else of interest I will certainly post it on here!

[Kieron]

Thinking about it, the hot rocks that I have found with my detector (Laser Rapier) never give a particularly strong signal like you describe. It is more like an echoing 'ping' similar to the sonar in an old war film Perhaps Graham is right about your specimen being man-made material.


Regards, Kieron

[brasky12]

There are many kinds of terrestrial rock that contain enough iron to give a signal with a metal detector or to be attracted to a magnet - I have found dozens of them while searching for meteorites at Ashdon and elsewhere.

Apologies for bumping but... I recently got my rare-earth magnet, began searching and within 15 minutes had a strong hit - but of course the streak test left a spanking grey trail it seems like responsive earth rocks are so abundant that searching in a non strewn-field is utterly futile.

[David Entwistle]

Apologies for bumping but... I recently got my rare-earth magnet, began searching and within 15 minutes had a strong hit - but of course the streak test left a spanking grey trail it seems like responsive earth rocks are so abundant that searching in a non strewn-field is utterly futile.

I'm not entirely sure what the following image shows, as I made it a while ago. I suspect it is the cumulative total known weight of all meteorites listed in the Catalogue of Meteorites. You may be able to name the falls responsible for the marked steps in 1949, 1969 and 1976 ...

Accretion Rate

The meteoritical database is accumulating meteorites at less than 400 kg per year; typically nearer to 100 kg per year. That accumulation of meteorites is spread across the planet's land mass surface area of 148,939,063.133 km2 (thanks Wikipedia). So, on average, we may expect to find (100000/148939063) 0.00067 g of meteoritic material falling per square kilometre per year. Even if I'm wildly pessimistic, it's not great odds of finding a meteorite outside of a known strewn field ...

On the other hand, rocks with significant iron content are interesting. If you can identify them as being igneous, sedimentary, metamorphic, or possibly man-made. And then work out why there are lots of them where you live, that could be very rewarding.

[Kieron]

The meteoritical database is accumulating meteorites at less than 400 kg per year; typically nearer to 100 kg per year. That accumulation of meteorites is spread across the planet's land mass surface area of 148,939,063.133 km2 (thanks Wikipedia). So, on average, we may expect to find (100000/148939063) 0.00067 g of meteoritic material falling per square kilometre per year. Even if I'm wildly pessimistic, it's not great odds of finding a meteorite outside of a known strewn field ...

On the other hand, rocks with significant iron content are interesting. If you can identify them as being igneous, sedimentary, metamorphic, or possibly man-made. And then work out why there are lots of them where you live, that could be very rewarding.

David,

Your reasoning is incorrect on a number of points. The meteorites that make their way into the database are not found distributed equally across the Earth's land surface. They are recovered only from areas with accessible terrain. I doubt that many meteorites are recovered from rainforests, for example, or from mountainous regions. Apart from which, surely the database reflects the rate at which meteorites are being classified, not the rate at which they are being recovered?