Natural deoxidation of iron

What happens if you breathe the eyeurn dust?

>>8512051
u die.

>>8512048
Deoxidation of iron? What if its just a chromatic effect? More iron oxide builds until the orange hue becomes so dark it appears black?

>>8512073
The sand is magnetic.

>>8512116
>silicone is magnetic

More at 11

>>8512127
It's iron sand you dumb shit

File: iron oxidation.png (74KB, 400x245px) Image search: [Google]

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Lower PH prefers deoxidation of iron. And silicates are easily oxidized (duh).

File: silicon and iron.png (100KB, 1784x820px) Image search: [Google]

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>>8512142
Or to expand on that, it's a net gain in stability if you compare the two half reactions side by side. It's not really odd if you consider that this is a fucking beach and there's water everywhere to allow reactions to take place.

>>8512154
Actually now that I think about it, +4 is already SiO2, so this explanation doesn't actually make any sense.

Must be some other pollution reacting with the iron.

>>8512158
I guess if the beach is super shitty and acidic, that would favor the H+ to latch onto the oxygen molecules of the iron oxide to form water.

>>8512048

The sand is unlikely to be pure iron. It's probably magnetite. Magnetite is already oxidised. Although it does react with oxygen to produce hematite (red rust like that coming from the cliffs), I'm not sure what the environmental conditions are to produce this or how quickly the reaction takes place.

Alternatively, the constant wave action on the beach could "polish" off any rust that has accrued while the tide is out (certainly the magnetite - hematite reaction would be slower under water).

Just a thought.

>>8512166
Polishing iron removes rust by subtracting it, not converting it.
i.e. by polishing rusty iron sand, you produce... rusty iron sand.

There's a rusty ship hull embedded in the sand, more evidence that it's not the waves.

And it does not appear to be magnetite, otherwise it wouldn't be orange to start with and would behave very oddly.

>>8512142
>silica is an oxide
>implying silica oxide

>>8512193
>And it does not appear to be magnetite, otherwise it wouldn't be orange to start with and would behave very oddly.

I thought you said the sand was black?

>>8512197
The sand is orange when deposited, but sand that is not recently deposited is black.

>>8512203

You said the orange sand is from iron oxide on the cliff.

Probably the sand is just being stained by whatever is leaching out of the cliff and the black sand was always there.

>>8512204
It's being actively deposited, but there's barely any of it: As I said, only recent deposits exist.

>>8512208

Well I don't know what to tell you without pictures.

Native iron is rare in nature because it oxidizes so quickly. It's more than likely just magnetite.

Note that magnetite can also be formed as rust, with water.

3 Fe + 4 H2O --> Fe3O4 + 4 H2

>>8512215
That equation describes oxidation, but either it starts out as iron oxide and deoxidises, or starts out as iron oxide and becomes magnetite.

>>8512217
>or starts out as iron oxide and becomes magnetite.

magnetite is iron oxide

>>8512048
The orange sand is not turning into black sand
The black sand is concentrated on the beach the same way it is concentrated by panning (such as for gold)
The orange sand runs off and the black sand is exposed at the same time (when it rains right)
The black sand is covered by lighter sand afterwards so the cycle can repeat

>>8512228
Even without reading the thread it should be obvious that is a silly explanation.

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>>8512127
>silicone

>>8512194
Do you even know the difference between an oxide and oxidation?

An oxide by definition contains one or multiple oxygen atoms, so even though I never even said silicon oxide, "silicates" means the same fucking thing.

Oxidation refers to the formal charge of the central atom. Oxidizing an element means decreasing the electron density around that particular atom by bonding electronegative atoms to it, like oxygen, nitrogen, or any halogen, in order to pull electrons away.

Silicon atoms readily oxidize to form a plethora of different oxygen-containing silicates. A silicate is literally any silicon atom or atoms bonded to oxygen.

I was wrong in my initial assumption that there was any release in energy (gain in stability) in going from SiO2 to something like Si2O7 but it honestly doesn't matter compared to you; you're so far off you're not even wrong.

This is most likely an acid base reaction (assuming that it's true that iron is actually deoxidizing).

File: butts.jpg (8KB, 261x193px) Image search: [Google]

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>>8512048
Its called Oxidation, not De-Oxidation

Maybe the sand has been stained by tar or oil. Was there an oil spill nearby?

>>8512650
why would the iron be De-oxidizing? Are you heating it? Are you melting it? Are you blasting it with coke and flux?

>>8512781
(4)H+ + FeO2 --> Fe + (2)H2O

Pouring acid on it I guess.

Don't think heat is required for this reaction considering how easily H2O is formed.

>>8512048
Neat. My hail marry guess is that the Iron (III) is being reduced by bacteria to Iron (II), which is black.

There's something called the Electron Transport Chain which is essentially how an organism creates energy (ATP). Typically, oxygen is the final acceptor and is reduced to water, but there are other electron acceptors that have been adapted by microbiota. It's been a long time since I've studied bacteriology, or even biology, so take that explanation with a grain of salt.

Another explanation that might be more likely is that over time, the red oxide is slowly washed down into the sand and diffuses to the point where its optical properties are diminished and its no longer noticeable.

>>8512048
OP every single person who posted in this thread so far doesn't know what the fuck they are talking about

You're going to have to give us more information about the composition of the cliffs. Could you try to provide a better description of the cliffs?

Where is this beach?

>>8512048
>fine dust of pure iron.

doesn't happen in nature

>>8513663
>every single person
and every married person

>>8513663
This. I want to see pics.

>>8513663
Patea beach.
The fairly-orange cliffs were formed volcanically, and they erode at a considerable pace.

While a lot of anons seem to insist that the erosion is not adding to the iron, and instead diluting it, I don't think fast-paced dilution would allow it to have the richest ironsand in the world.

>>8513968
fuck you Im married and I know what Im talking about

>>8512048
prob magnesium dust

>>8514284
The person that guy originally responded to did not post this.

>>8514282
Okay OP I have your answer.

The article I've linked below indicates that the most recent volcanic succession in your area is andesitic in composition. Actual composition could vary locally thus the cliffs you speak of may not be strictly andesitic, but likely close enough for the purpose of this analysis. These andesites contain iron-bearing minerals such as pyroxenes and magnetite. There may also be olivine and amphibole present in the sands, perhaps even in the cliffs themselves as well.
The iron in these minerals is in its reduced form. Conditions at the Earth's surface are currently oxidizing. When the cliffs are exposed and chemically weathered the iron in these minerals becomes oxidized, forming an iron oxide that is orange in colour. This process is somewhat similar to the way rust forms on the body of a car. To be continued in next post

https://www.britannica.com/science/beach-placer

http://www.tandfonline.com/doi/pdf/10.1080/00288306.1967.10431086

>>8514282
>>8514344

The chemical weathering of these cliffs occurs more slowly than their physical breakdown to detrital minerals. These black minerals, containing iron still in its reduced form, are remobilized and deposited to form a beach placer. Through a variety of sedimentological mechanisms, the densest minerals are separated and deposited to form a placer deposit (in this case a beach placer). The densest mineral here is magnetite which is quite rich in iron, forming your rich ironsand.

It is likely that the succession forming your cliffs is being physically eroded very rapidly elsewhere along the coastline and the magnetite is being brought to your beach by longshore currents.

The exact mechanisms by which the magnetite is concentrated are complicated and probably beyond the scope of this explanation. You might find the article I've provided to be of interest.

>>8514344
>>8514355

I said this already

>>8512166

>>8514344
>>8514355
The oxidised iron actually comes from pores in the rock, it's not exposed iron that then oxidises.
I don't have and can't find any pictures of a leaking cliff, but it's bright orange, so I'd say that any amounts of black minerals are negligible.

It's unlikely that this process is not somehow turning orange minerals black, because no black minerals come out of the cliffs, yet there are no orange minerals on the beach except where new sand is being added.

>>8514549

Ok

The oxidized iron comes from groundwater percolating through the cliff and oxidizing the minerals there. When it rains it washes out of the cliff and onto the beach.

The black minerals on the beach are an unrelated placer deposit of magnetite. The black and orange minerals are not part of the same system. They just happen to be in the same place.

>>8512048
Very fine? Check. Colorless? Check. You answered your own question: iron particles de-ionized, or without charge. That's not to say that they won't have charge, but that the charge they had as non-oxidized solid iron, that charge has been removed, destroying its complex bonding potential. Exposure to air will revitalize its charge in dust form tho.

>>8514604
Hi I'm the guy that posted the articles above

You're correct about the groundwater moving through the cliff

However the other things you said are not true. The placer deposit is not unrelated; it is derived from the same succession as the cliffs.

File: PateaBeachIronOxide.png (146KB, 600x399px) Image search: [Google]

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>>8512215
>>8514344
>>8514604

Geology and Geophysics faggot here.
My first assumption was that it was the chemical weathering of pyrite in the cliffs.

2FeS2(s) (Pyrite) + 7O2(g) + 2H2O(l) = 2Fe2+(aq) + 4SO42−(aq) + 4H+(aq)

4Fe2+(aq) + O2(g) + 4H+(aq) = 4Fe3+(aq) + 2H2O(l)

Fe3+ has a naturally orange - red coloration to it.

You can see orange runny rusty shit in concrete all of the time, it's caused by pyrite weathering.

Then op told us the beach, which they should've done in the first post. I did some digging. I found a picture of the beach and recognized that the rock around the beach looks very basaltic. Magnetite now makes since, because pyroxenes olivine, and amphibole make up basalt. I found a particular paper on the composition of the sand. Pic very related. I imagine that the basaltic rock mechanically weathered through the tidal action of the ocean water. The constant supply of water moving back and forth may somehow influence the chemical weathering of mineral fragments that had / have weathered mechanically. The Fe 2+ and 3+ content is from the minerals. The olivine and amphibole in the rock must have a high content of Iron, rather than magnesium.

As far as why does the sand keep turning different colors? I think it's just the constant oxidation and reduction of hematite and magnetite due to the cyclic nature of tides. Hematite ( iron(III) oxide ) giving it an orange color, and magnetite ( 2 iron (III) 1 iron (II) oxide ) giving it an orange and black color as well.

I don't really know if there's a 100% true answer to this though. I know that /sci/ likes the absolute truth, but there really isn't absolute truth in geology.

This video is really appropriate for this thread though: https://www.youtube.com/watch?v=jROEiR21krg

It's clear that some of you faggots don't give a shit about rocks.

>>8516331
Fellow Geologist here in concurence with this chaps explanation. I should like to point something out to OP and perhaps some other fellows in this thread that has been overlooked: the nature of any typical [non-deltaic] shoreline is dominated by sediment transport, usually by processes of Long-shore currents, rip-currents and tidal currents (amongst other possible currents).
With this in mind, it may be worth considering the transport which the 'Orange Sediment' is forced to undergo. That is to say, the [presumed] Heamatite proximal to the cliff face is periodically exposed to and transported by incoming seawater, thus removing it from the backshore/foreshore environment.
This periodic transport may explain why the Heamatite is only found proximal to the cliffs.

It would be audacious to suggest that the Heamatite is not chemically altered during its exposure to seawtaer, however; seawater is a very strong geochemical fluid and would almost certainly have an affect on any heamatite present.

>>8516331
>>8517591
You morons are a fucking disgrace to the profession

I sincerely hope you're just students

>>8516331
>>8517591

Wow

Please never practice geoscience

If you do practice geoscience you are a danger to the public. If you hold any professional credential then you should rescind it immediately.

>>8519032
>>8519037
Samefagging is real

>>8519119
Yes I made both of those posts.

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>>8519032
>>8519037
What the fuck are you talking about?

>>8512048
I want to marry and impregnate repeatedly a tigergirl.