It was collected in grey sand. There are some of them.Did it have relation with ancient iron smelting?
Based on the photographs, these appear to be bog iron (FeO (OH)). Bog iron typically forms in swamps or lakes above an indurated layer like dense clay. It also can form lumps, concretions, and/or tabular slabs in the basal sections of some poorly-drained level soils above a hardpan or indurate layer. Bog iron is considered one of the first iron ores to be used in early smelting. The Vikings are known to have extensively used bog iron in their iron smelting.
Grey sand and light grey or bluish-grey clay usually are indicators of a reduced oxygen environment, past or present. Reduced environment soils are associated with swamps, lakes, slack water streams, and other wet locations where waterlogged soils are deprived of oxygen. Bog iron usually forms around a nucleus within this wet environment and the iron cations attract other iron molecules that are leached through the soil over time.
While there is a slim chance that these could be iron slag, if you do not have indications of smelting in the area, then they are likely natural bog iron.
Is it magnetic? Where was it found? If it is magnetic, it could be pieces of iron meteorites. If so, it should consist mostly of iron. Difficult to tell just from the pictures. Try http://meteorite-identification.com/streak.html for first simple tests or hints who could help you. You can try the magnet test and the streak test. If you hesitate to do the file test because you do not want to damage the samples, ask an expert.
Dear James
Thank you very much for your knowledgeable explanation.
“Grey sand and light grey or bluish-grey clay usually are indicators of a reduced oxygen environment, past or present. Reduced environment soils are associated with swamps, lakes, slack water streams, and other wet locations where waterlogged soils are deprived of oxygen.”
The explanation helps me understand why Bog iron is in grey sand.
It is bog iron most likely. About bog iron, does it have to be magnetic? If a bog iron contains a lot of impurity substance, will it lose magnetic property.
Dear Erik
Thank you very much for the helpful link. Because I can’t open the webpage completely, I don’t know part 1---part3 steps. Magnetic test is easy doing with a magnet. But what is the streak test?
Because there were 6 or 8 pieces of the objects in the grey sands, my friend thought these may be meteorites, so she picked one sample. I thought it was iron cake of ancient iron smelting.
Tomorrow I let my friend hammer it to test its hardness and inside. Later I will post the result.
Dear Chun,
James Green's explanation is highly likely. In my home area of Wester Ross, Scotland, early iron smelting was common and 'bloomeries' or charcoal furnaces are still to be found. Bog iron was the ore used and your photos resemble such. In South Erradale a dry-stone dyke was built entirely of bog iron nodules. Unless slag heaps lie close to the bog iron you found, it is most likely that these are in situ deposits formed in anaerobic conditions in eg. peat bogs. The grade of ore would be low, probably
Dear Chun Liu,
the streak test is whether the material leaves a streak when you scratch it over the unglaced side of a ceramic tile. While common iron ores like hematite and magnetite will leave a streak (hematite:red, magnetite: black), meteorites won't.
Bog iron is mainly goethit which is only weakly magnetic, so this could be the first test.
If it is a meteorite, it will contain some radionuclides, like Mn-53 or Al-26, in amounts exceeding terrestrial concentrations. But those are not easy to measure (and of course, not even slightly in the harmful range). If it's magnetic and you assume it's meteorite then the next test would be whether it contains considerable amounts of nickel which would be a relatively simple chemical test. Ni is present in terrestrial materials only in traces.
The precipitation of iron molecules through the soil creates a variety of mineral forms, from round concretions of hematite or limonite to tabular slabs of ferruginous sandstone or mudstone depending on environmental conditions, thus the amount of iron varies in these minerals. They can have moderate to weak or nil response to a magnet.
Shiny metal flakes probably mica from sedimentary matrix cemented with ferrous oxide.
So overall, it's probably no meteoritic material... also the new 2 pictures look less "meteoritic" than the previous. I tend to agree it's bog iron. To be finally sure, you can try to test the Nickel content...
Yep, I concur with the consensus, not slag, it's most likely "bog" iron.
Dear Ervan and Bob
Thank you for your opinion.
I have taken a few days studying the information about a slag on the linked webpage which Professor Erik Strub offered. So I do not agree the view “it is bog iron. “I think it is slag.
The reason is:
1) . It has a thick Fusion Crust;
2) . The kind of objects only appeared in 2-3 square meters area.
3) The surface and the fusion crust suggest that it has been processed in high temperature.
4) The little of tiny shiny metal flakes maybe is Ni. , but the concentration is very low.
5). The holes on the surface may be formed by gas bubbles.
Dear Chun Liu,
It looks like a picture of meteorite.
Regards, Shafagat
Dear Chun Li,
It ought to be very simple to test whether it's iron slag or bog-iron ... determine how powerfully a small magnet is attracted to it. If a small magnet sticks, its likely slag, if not, then (low-grade) bog iron (ore).
Probably, you can consider is a fragment of slag. Have you another presence of metallurgic technology in the context?
Dear Erik Strub
About the test of Nickel content, I think it is not easy to do with it, because it contains a little of tiny shiny metal flakes. But I have another stone with a lot of same shine metal flakes. Would you give me an easy way to test what it is?
When it is grinded to powder, the shining substances still exist in the powder.and magnet doesn’t attract the shining substances. I think some metal deposited on the stone.
Chun Li,
The photo you posted in reply to Ervan and Bob definitely looks like slag and totally different than the first photos. Did that one come from the same location? Bog iron can form a crust, particularly when ferric materials are precipitated out at a faster rate than previously, such as during a long wet period or stream cutting into an iron deposit. The last looks like an iron-stained pebble which could have natural hematite/limonite adhering to it or because it has come into contact with an iron object.
If the metal flakes were Nickel, they would be magnetic. If there is nickel, a acidic solution would be green. Neutralisation with ammonia (carefully!) would yield first a green precipitation which redissolves in to a dark blue solution. But from everything we know up to now, I don't think it's of meteoritic origin.
Dear Chun Li,
Your two pebble photos show clear iron staining most probably attributable to iron pan development in a sandy or morainic soil. I have attached a photo of a podsol in which acid from the peat above leaches ferric salts out of the sandy morainic parent material to form a grey ashen layer. The iron is precipitated out then to form an iron pan, where anaerobic conditions prevail. Any clasts or pebbles get coated with the iron deposits.
How does that relate to your original bog iron specimens? The processes are similar in that acidic conditions lead to the removal of iron in solution which are then precipated out where anaerobic conditions prevail. So bog iron and iron pan are both products of the removal and re-location of ferric salts.
George
James A Green，
The stone in the first posted photos is a whole one. Then I hammered it to four pieces for observing its inside. The stone you mentioned is one of the quarters.
It is like rusty iron lump. It is as heavier as an iron lump. What puzzled me is why there are so many big and small holes in the stone. Are there some holes in Bog iron lumps?
By the way I think it with burned extrinsic feature
Dear Erik ,
The weathered surface is thin; its inside is very hard. The powder scraped with an agate is not magnet. But the powder scraped with iron scissors is magnet. The powder is attracted by the scissors (1and2 pictures). After washing with water the powder still is attracted on the scissors (the third picture). There are some shining dots in the powder.
The researchers' teams at the Römisch-Germanisches Zentralmuseum and Curt engelhorn-Zentrum at Mannheim (see their homepages in th net) could help you. Why not send them he photos and a detailed report ?
Dear Chun,
i am very sorry to hear of your husband's operation. I do hope he is making good progress.
The weak magnetism does support Eric's suggestion that it could be goethite the iron ore common in bog iron.
with kind regards
George
Chun,
If you have Microsoft Office 2010, open your photo in Microsoft Office 2010 (picture app) and go to PICTURE on the main menu; click on it and it will give you the option to compress your file. Suggest you compress to 'document' size.
The other option is to insert your photo into a WORD document and click on the photo; it will show PICTURE FORMAT along the top; click on Picture Format and it will give you the option 'Compress'; click on it and choose 'Print (220ppi)'; click OK and you will have reduced the file size to manageable size without loss of resolution.
I am not acquaint with the ipad system but, if WORD is not available, I am sure some of your colleagues will explain the ipad method to you. You will then be able to download it on to RG.
Kind regards
George
PS: if you are really stuck, send me your photo to - [email protected] - and I will compress it here and return it to you
Chun Liu,
The high-resolution image shows that the specimen has a very high iron content in some locations. However, in my opinion, it is "bog iron". For me the clue is the vesicles that are readily apparent in the image. These appear as linear voids along the fracture line and round holes penetrating the specimen. In a couple of instances the linear vesicles are accompanied by a hole. These vesicles are where roots (rootlets) were located that were encapsulated by the bog iron. Once encapsulated, the root structure prevents the ferric oxides from filling the space and eventually the rootlets rot out, leaving the holes.
The depth and orientation of the vesicles precludes it from being slag because molten slag deposited on the ground would leave plant impressions on or near the surface, not deeply embedded within the structure. This is because the slag floating on molten iron is composed primarily of solids and semi-solids. Thus it would be unlikely to "flow" around plant materials and leave the clean holes that are observed in the specimen.
A note: I am an archaeologist with a strong background in geomorphology and geology. However, a sedimentary geologist could tell you more about the specimen.
JAG
Dear Chun, thanks for the picture. The analysis of James seems very reasonable to me.
Dear all
First I say the metal which giving out silver light may be not all iron elements, because it is weak magnetic.
If it is iron , it is Fe（0）, but the irons in the earth are Fe(II) or Fe(III) in the common situation.
I have seen a meteorite which contain a very small piece Fe (0) with strong magnetic.
Dear all
“The clue is the vesicles that are readily apparent in the image. These appear as linear voids along the fracture line and round holes penetrating the specimen. In a couple of instances the linear vesicles are accompanied by a hole.
At first I also think as you.
Please pay your attention on the wall of the linear voids. There are hard walls under Fe2O3. The hard walls contain reach metals.
My personal view, the linear voids contained some element which reacts with air or water and produced gas and high heat to make.
Dear all
Today I have found a The Chemical Test for meteorite of Fe and Ni rich. Do you think it is a good way?
-Clean up the potential meteorite real good
- Use some vinegar to remove the surface rust (the vinegar is acid and it helps to remove some of the rust)
- Test for Nickel-Iron - if it tests positive then it has 99.9% chance of being a meteorite,
this is of course if the test was done correctly.
Chun Liu,
Not knowing what the test is, it is hard to say. I think there are a lot a scam tests out there because meteorites fetch high prices and people are always willing to spend money on the chance of getting richer.
The main chemical to test for nickel in meteorites is Dimethylglyoxime. A 1945 Harvard University meteorite test that students could use first tests for iron, then nickel. Since a magnet in almost every case will stick to a meteorite because of the high iron content, the telling test is for nickel. In order to perform the Harvard test (below), you have to powder a piece of the sample. While there might be tests in which this is unnecessary, in seems like a reasonable process than just putting a drop on the surface.
http://adsabs.harvard.edu/full/1945PA.....53...41.
Dear all
At first I also do not know what the vinegar test is for. I have done it. It is interesting. I used three Chemical substances_some vinegar, a kind of disinfectant (三氯异氰尿酸C3N3O3Cl3) and a kind of detergent used cleaning toilet.
Because the sample which used before only a little left, so my friend and I find another one do the tests. （my friend is a meteorites collector）
First we brushed the surface with some vinegar softly, and we did not find clear change. Putting it in the vinegar for 5 0r 10 minutes then brushed the surface and polished the surface with dry cloth. The surface gives out silver light in some area.
Dear all
The three kind of chemical solution all can remove the surface rust. The disinfectant (三氯异氰尿酸C3N3O3Cl3) and the detergent used cleaning toilet remove the rust more faster and easier than vinegar. The small one was cleaned with the disinfectant. And the big one was cleaned with the detergent. But I think the chemical methods can affect the science value of a meteorite.
Hello Chun,
the researchers at Curt Engelhorn-Archäometriezentrum at mannheim, Germany, sureluy would be pleased to help you. You find thei page in the net.
Kindly
Joachim
@Chun: unless you treat the complete meteorit chemically, it won't affect the scientific value. Any serious scientific investigation of meteorites is most probably partly destructive anyway.
@Erik
I have found an interesting phenomenon. The first picture was taken before using disinfectant (三氯异氰尿酸C3N3O3Cl3) and vinegar. It shows there are some metals in the stone. But a few days later I can’t found the metals, even I filed it again (the second picture). Did Cls react with the metals? What is metal? But the metals in surface have not affected by the using disinfectant (三氯异氰尿酸C3N3O3Cl3) and vinegar. (The third picture)
Dear all
The silver light metals are different metals, because the metals give out different color silver light. From a certain angle, some metals can show light like FrogSpawn. You down load the picture, and enlarge the picture, you will see. The surface have been washed with the disinfectant (三氯异氰尿酸C3N3O3Cl3) heavily, so some metals have been washed away.
Dear all
I post another picture. After downloading the picture, you can enlarge the picture a lot of times and you can see silver-purple light and silver- blue light metals. Because it is magnetic and the metal do not rusted, so I think that one kind of the metals maybe Nickels.
Dear all
Today I have battered an iron ore to pieces. The patterns of re-crystaled metal in the rock amaze me, so I share the picture with you. You have to download the pictures and enlarge the picture to 300 times. The picture with flash lamp you can see he different metal-reflected light. The picture without flash lamp, you can see cottony re-crystal. How did the patterns form？Wishing to share your scientific viewpoint Dear experts.
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