I've sent dozens of emails out this morning to various university geology departments and grad students with pictures of something a friend found. If
anybody here would like to venture an opinion, please, feel free but what I'm really looking for is someone who can point me in the right direction
for answers on this thing.
Now I didn't take these pictures and they really, really suck. I am going down and taking my own.
She found this thing along the shoreline of a Chesapeake Bay feeder years ago at a really low tide. It is heavy as hell but not metallic (or at least
a magnet doesn't think so).
[Edited on 15-1-2009 by givemeliberty]
Sauron - 15-1-2009 at 09:13
Send a U2U to chemrox.
He's a geologist.vulture - 15-1-2009 at 10:40
Quote:
It is heavy as hell but not metallic (or at least a magnet doesn't think so).
That simply means it's not ferromagnetic. It could still be a metal or a compound thereof.hissingnoise - 15-1-2009 at 11:39
It certainly looks like a lump of metal that's been in the water for some time.
And probably came from a passing ship.
A clearer picture would give a better idea, though.givemeliberty - 15-1-2009 at 12:47
If it was metal of some kind, wouldn't it have been covered in rust? I don't know.
I didn't see it when she first found it but according to her and her husband, the way you see it is the way she found it except for the mud.
I will U2U chemrox.
And yes, I will get better pictures. I particularly want to show the side where it looks like it had been broken off of a larger object and the odd
cavity. The cavity puts me in mind of a void from a casting process.
I just got an email from the U 0f MD. They want better pictures, too. LOL. I never should have let her handle the camera.
I appreciate you guys taking the time to look at it and venture an opinion. It's not exactly chemistry but I thought if I wanted some bright people to
look at it, this is the place.Xenoid - 15-1-2009 at 13:28
Well, I am (was) a geologist and (assuming it is not a bit of rusty old iron or steel) it looks like a ferruginous (iron oxide/hydroxide) nodule or
concretion to me! They are very common, in fact huge iron ore deposits can form in a similar fashion. It's probably composed of minerals such as
limonite, goethite and hematite.
There are many environments and processes that can give rise to the formation of such nodules, but basically they will form in soil or sediments at
the interface where oxidising fresh water interacts with iron rich solutions. If cut or broken open it will probably show concentric growth rings.
Do a Google search for some of the terms above and you should get plenty of information.givemeliberty - 15-1-2009 at 13:57
Well I'll be damned. Kind of like a stalagmite then. So the irregular void in the center could have been whatever it formed around which rotted away?
And there are probably more of them that are just covered by silt (lots and lots of silt it being in the headwaters of the Chesapeake Bay).
Well, that all makes perfect sense to me.
Now how am I going to break it to them that
A: no, it's not kryptonite
B: no, you are not rich
C: no, it's not a meteorite
D: no, cavemen did not make it
and finally
E: no, it is not a fossilized dinosaur turd?
Hey, listen, thank you so much for the information. I'm sending them a dozen links I found about the stuff. That'll keep them busy for a while.hissingnoise - 15-1-2009 at 14:24
Quote:
Originally posted by givemeliberty
Kind of like a stalagmite then.
Or possibly a stalactite, even. . .Xenoid - 15-1-2009 at 14:26
Oh!
Looking at the photo again and reading your description, I gather the left part of the nodule is a broken surface, and the lighter area is a cavity.
If this is the case then I might suggest that the object is simply a "rust" nodule formed around a preexisting piece of iron or steel and that it has
completely eroded away, leaving the cavity.
Natural ferruginous nodules and concretions may also contain cavities or a central cavity, left when softer material that the concretion "grew" on or
incorporated, are eroded.
Are there concentric growth lines on the broken surface?givemeliberty - 15-1-2009 at 14:58
Ummmm, thinking...thinking. No, not that I can remember. I kind of wanted to rinse it off a bit more with maybe a little bit of 409 or Windex or
something but the husband was fearful of diminishing the value (Antiques Roadshow episode of guy who refinished a highboy thereby reducing the value
from the millions of dollars). All he would let me do was spit on it a bit.
But no, I'd say no rings but now I know to even look for rings, when I go back to take a better picture, I'll look closer.JohnWW - 15-1-2009 at 19:13
Possibly a meteorite, - an ultrabasic stony meteorite with a high content of ferrous silicate, but with little or no metallic Fe, Co, or Ni, or their
magnetic (II) or (III) oxides. ("Iron" meteorites, besides Fe, Co, Ni, also contain smaller amounts of Mn, Cr, Cu, V, Ti, Mo, W, Ag, Au, platinum
metals, and are ferromagnetic, and are believed similar in composition to Earth's core). But if it is not such a meteorite,, and "is heavy as hell",
too heavy for a silicate rock composition, andnon-magnetic, another possibility is that it is from a spill of molten Pb. It is unlikely to be from a
spill of molten U, as that is believed to be ferromagnetic, like many rare-earth metals.chemrox - 20-1-2009 at 20:08
It looks like a meteorite. Someone brought one like it by my office a few years ago. Did you say where you found it?Sedit - 20-1-2009 at 21:14
Iv seen these a million times being as my grandfather was part of the archaeological society around here down in Southern NJ for a while..
Being in where it was found and the shape of it I would have to say that it is shaped flint for an axe head.
From the angle of the picture the right side was sharp for cutting and the left was used for canoe shaping ect...
If its not that i would be shocked because i have seen hundreds of indian artifacts that look just like that.
Matter of fact.....I have a few and ill try to post some pictures up if i can get my web cam working clear.
"
So the irregular void in the center could have been whatever it formed around which rotted away? "
This is where it was shaped and the rope was made to fit it and hold it in place around the handle stick.
Q: is it flint or a sand stone material so i know which peice to find and take a picture of?
[Edited on 21-1-2009 by Sedit]
[Edited on 21-1-2009 by Sedit]kmno4 - 22-1-2009 at 15:24
This topic looks like quiz
I would be able to do X-ray analysis of it (for common metals, with X-MET 3000) with ~1g sample, but from US to EU is a long way (via post).
Try to find someone with access to X-ray analyzer of metals.not_important - 22-1-2009 at 17:58
Find its specific gravity, which will allow you to rule out many possibilities
you don't need to be as accurate as in those web sites, x.y +- 0.2 would allow considerable narrowing down.
Then tap at a bump on it with a geologist's pick or an old chisel, look for fracture or deformation.
A bead test on a tiny fragment can help determine metal content. In fact, a book such as this one http://www.archive.org/details/manualofdetermin033327mbp would be useful, even though it is over a century old; not all of us have access to
X-ray fluorescence gear :-)barbs09 - 22-1-2009 at 21:12
Hi,
I am a geologist who spent the last two years mapping very similar looking rock types in the outback of West Australia. In fact the piece of rock in
the photo would probably look at home amongst all the other heavy brown rocks on my mantle piece. It looks like it could be either a piece of Banded
Iron Formation (BIF) or a piece of gossan. Both rock types are usually Fe-rich and therefore dense, brown and can contain voids.
BIF is one of the main iron ores and is usually comprised of magnetite or haematite. This could be hematite if it is non-magnetic. BIF was formed
during the Archaean by the global oxidation of Fe++ rich oceans to Fe+++ with subsequent widespread precipitation of iron oxides. It would be
interesting to consult a geological map of the region to see if BIF outcrops up catchment.
Another possibility is a piece of gossan. These rocks started off as massive sulphides which underwent oxidation and weathering at the surface to Fe
oxides. The chocolate brown colour of the rock in the photo looks like goethite, as suggested in the second paragraphs of Xenoid’s first post,
which is a common iron oxy-hydroxide mineral (something like FeO.OH). I wonder if there is a mine or metalliferous occurrence up stream? The rounded
look to the rock suggests transportation down a river or perhaps reworking on the beach environment. The voids mentioned might be remnants of boxwork
weathering which is caused by the selective dissolution of pyrite grains or another weatherable mineral.
Just a thoughtchemrox - 23-1-2009 at 19:35
I'm also a geologist and I like the Aussies answer too. Cut the damned thing in half and/or get a powder camera analysis of it.Sedit - 23-1-2009 at 23:28
" This could be hematite if it is non-magnetic"
What? And your a geologist?
Hematite sticks to a magnet quite well. Im not sure what you are use to but I personaly have had a few samples and the loved magnets.
Look im from the Chesapeake Bay area. These things are so common that if you go out into a farmers field when it has been freashly plowed and after a
good rain... you can find these by the masses.
There is so many guessing games like Kmno4 said its like a quiz show...What do i win?
givemeliberty brother/sister what you have is an axe head... take it to any professional around your area(I know they are there so no bull shit) and
they will tell you the same thing.
My grandfather is a pack rat of this sort of thing and his arrow head collection takes up more space then my chemistry collection(and thats saying
alot)
Check it out ....can you send some more detailed pictures of the very thinest parts with light shining thru if possible?...(if that makes sence)
Do youknow what flint looks like givemeliberty...because I have seen three types atlest with flint being the most common.barbs09 - 24-1-2009 at 01:25
I try to be a good geologist-honest. Anyway Sedit you are correct. After a bit of googling, haematite is apparently magnetic though according to a
few web pages and an old text book I dug out, very weakly magnetic. I passed my super duper hard drive magnet over my nice piece of haematite and
while the magnet was attracted to it, it was not magnetic enough to be picked up or even barely moved along a horizontal surface by the magnet. Maybe
your sample had a slight magnetite content? I found a web page explaining why haematite is only weakly magnetic compared to its more magnetic
brother. <http://www.tc.umn.edu/~smith213/ma.htm>
Cheers guys, By the way Chemrox good to hear from a fellow geologist and I’m not an Aussie but a New Zealanderfreem851 - 25-1-2009 at 10:42
My first thought was hematite also. Bust it open, take a look at the grains, their size and color, check the streak, etc. Maybe get a geology
undergrad or grad student to do a thin section for you.
