Meteorite or common rock?

[Aidan]

Hello! My friend found a rock on a beach near Ancona, in central Italy, and now he's convinced it's a meteorite. I have some doubts, however: it looks too cracky and porous. I'm attaching a few pictures of the rock: could someone give me an opinion?

Thank you very much for the kind attention,
Stefania

 

[Ibix]

@davenn is our meteorite expert.

 

[Vanadium 50]

By "porous" do you mean there are voids inside the rock?
The white-ish mineral - is that quartz?

 

[Aidan]

I actually have more detailed images of the inner surface of the rock, because, as you can see, it craked in different fragments.

 

[Aidan]

Also, if it can help, the rock was found near (1,3 km away) an oil refinery.

 

[Baluncore]

1. It could be a local coarse grained sedimentary rock, rounded in a stream or on the beach. The small stones that make up the rock were rounded during the original deposition. The layering of grain size suggests a river deposit with some flood events depositing the biggest grains.

2. Maybe a rock from a volcanic cone, stratified and then weathered. Ignimbrite? But that is not where I would expect a local volcano. How far from Vesuvius?

3. It is deeply weathered and appears to have iron oxide staining. Maybe it is waste from an iron refinery, that was dumped to make a sea wall.

4. It might be a ship's ballast, dumped before an empty ship was loaded in the local port. It could have come from any port on the Mediterranean, over the last 3000 years.

5. I think meteorite is unlikely because of the stratification and the rounded grains.

Did you look for other similar rocks nearby on the beach ?
Was the area glaciated in the last ice age ?
Does it contain metal ?
Is it magnetic ?

 

[Aidan]

Hi, thanks for the detailed answer! The owner of the rock intends to get it certified as a metheorite, so he'll seek a professional. I'll keep you posted when something comes up.
The place where he found it was a rocky beach, but the rocks come from somewhere else, since they were planted there in order to mitigate coastal erosion. And yes, there is a river nearby, but no volcano. The rock is only very very slightly magnetic.

Anyway, I really find the subject fascinating: the "ingredients" in the universe are the same (pace Aristotle), but the process of a rock formation are made visibile, to an expert eye, in different manners, which makes possibile to ascertain a terrestrial or an extraterrestrial origin. I think that a geology book is mandatory to investigate the topic.

 

[davenn]

Hello! My friend found a rock on a beach near Ancona, in central Italy, and now he's convinced it's a meteorite. I have some doubts, however: it looks too cracky and porous. I'm attaching a few pictures of the rock: could someone give me an opinion?

Thank you very much for the kind attention,
Stefania

hi you Stefania

OK first up, I don't see any evidence of any of them being a meteorite
OK let's look at each in turn :)

1) this one looks very volcanic in origin ... vesicles ( gas bubble holes) are a dead giveaway that it isn't a meteorite

2) tho this appears to have objects that are similar to chondrules - I would like to see a closer look
I suspect they may be crystal vugs and again the sample appears to have vesicles

3) No, definitely not. This sample appears to be full of quartz or other white minerals
you would never see a meteorite looking so white like that

4) I have no idea of the scale of this image, tho it appears to be well magnified
It also doe
snt have the looks of a meteorite

The owner of the rock intends to get it certified as a metheorite, so he'll seek a professional.

I can pretty much guarantee that they won't get certification
Any professional or semi pro in meteorites like myself would dismiss them immediately
Ohhh and certification costs reasonable amounts of money :)
Personally, I wouldn't want to waste the time of a lab to look at them.
Not a lot of point taking them to an average geologist either, most of them wouldn't know what a meteorite looks like ;)

I have been collecting and studying them for ~ 30 years, have over 270 meteorites in my collection from all over the world
and of all sorts of different types

here's one of my threads on meteorites ...
https://www.physicsforums.com/threads/adding-more-meteorites-to-my-collection.986095/

best regards
Dave