r/askgeology • • Jan 05 '26

ID request New Ruling on ID posts.

4 Upvotes

Posts are now allowed to be requests for ID, although you must attempt to post to r/whatisthisrock or r/fossilid BEFORE posting here.

Mineral ID's have always been allowed and will continue to be.

Additionally, new post flairs have been added. Please select a flair when able.

Have fun!


r/askgeology • • 9h ago

Method of Formation What could cause this type of weathering?

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21 Upvotes

Went to Mt. Baker today and noticed that the rocks near Artist's Point seem to all be weathered in this very uniform way, as if cut into slices. Our theories are glacier movement and thermal expansion, but I don't know what to make of it.


r/askgeology • • 15h ago

ID request Amonite?

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13 Upvotes

Found this in el chalten Argentina. The last one is what I later saw in the visitor center


r/askgeology • • 12h ago

How?

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3 Upvotes

What processes caused this rock to look like this looks like it was carved up with a very hot knife or spoon


r/askgeology • • 19h ago

Method of Formation Can anyone tell me about this rock from Jamaica?

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3 Upvotes

I'm not a geologist but I'm genuinely curious about this rock I found on a beach in the north of Jamaica. It's quite soft, chalky, very porous and has little red and green flecks in it. It also has a delicate, papery matter stuck to it which I assume is seaweed remains - but I could be wrong!!

Can anyone tell me how it might have formed, what the red flecks are and what the papery matter is?

Much appreciated!!


r/askgeology • • 19h ago

Broken speleothems or fossil? Northern Thailand

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3 Upvotes

r/askgeology • • 18h ago

Strange formations near Mount Amiata

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1 Upvotes

r/askgeology • • 1d ago

Observational Question We can eat limited amounts of food-grade sodium chloride and calcium carbonate. Are there any other rocks we can safely eat?

60 Upvotes

r/askgeology • • 1d ago

What are these strange bowl-shaped formations in the Mojave Desert? Spotted from a plane flying from Los Angeles toward Las Vegas.

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20 Upvotes

r/askgeology • • 1d ago

ID request I have two specimens from relative close proximity, could this be sulfides ?The yellowed mineral is on a much softer rock and the last two pictures are a much harder stone and more silver color .

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5 Upvotes

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r/askgeology • • 1d ago

Solid throughout, found in MA among lots of Roxbury conglomerate and what I think is serpentine. Any ideas?

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1 Upvotes

r/askgeology • • 1d ago

technical question How would a person go about making obsidian?

0 Upvotes

For a worldbuilding project. Imagine you have access to metal but no power tools. What sorts of variables would you need to control? What might make manmade obsidian worse/better than natural stuff? Thanks.


r/askgeology • • 2d ago

ID request Help with rock and fossil ID

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17 Upvotes

Hiya, my grandfather was a geologist and we recently found these in his collection would anyone be able to help ID these? Thank you so much in advance 😊


r/askgeology • • 2d ago

Method of Formation What causes ringing rocks?

5 Upvotes

So there are ringing rocks in various places of the world, which ring like a bell when struck. Why? What is going on with the properties of the rock that make them ring? Is this replicable?

Are there any scientific papers on this subject where I could learn more?

Example: https://en.wikipedia.org/wiki/Ringing_rocks


r/askgeology • • 2d ago

I need help identifyi g this rock

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2 Upvotes

I was originally thinking flint, but there's that weird iridescent patch on the back, it was found at the base of the Tatra mountains near a water source, near zakapone in poland. It scratched glass, aluminum, and my fingernail easily.


r/askgeology • • 2d ago

Observational Question Someone to explain this rock formation

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2 Upvotes

r/askgeology • • 3d ago

Geology professor I had a lot of respect for said climate change is a matter of controversy, invoked Crichton’s ā€˜State of Fear’. What do you think?

20 Upvotes

I’ll begin by stating that English is not my first language, and am studying Mineral and Metallurgical Engineering at a famous mining/geology school. As part of our sophomore year cross-departmental courses, we have a course in the geology department called Geology for Engineering and Sciences; common with sophomores from the geophysics and mining departments. The course structure is really nice, covers mineralogy, mineral and ore formation, Bowen’s reaction series; fold, block mountains, landscapes and contour/relief maps, palaeontology, seismology, and continental drift. That is of course tangential but while teaching us continental drift and the evidence for it, he strayed into the idea of climate change denial and how he believed climate change and global warming is a highly exaggerated idea. He brought up Michael Crichton’s famous book denying climate change, State of Fear; and while he did admit that there are petroleum and coal lobbies supporting this agenda, his counter to us was also that the idea of climate change and global warming being real phenomena to concern us would greatly help the electric and renewable energy/solar energy enormously. He pointed out how in a number of inland glaciers, ice buildup data during a series of years has been higher than the ice that actually melted. So there was a net gain of ice in these glaciers, opposite to what global warming theorists might suggest. What do you guys think? He’s a really respectable person, done his higher studies in Virginia Tech and the Royal School of Mines. Really fun to study from. I discussed this with him afterwards for quite some while, he had essentially the opinion that a full transition from petroleum to renewable energy is impossible and idealistic. He even said how there were theories suggesting petroleum itself is not fossil fuel per se, but rather derivatives of meteorites that landed on the earth. What are your opinions? I’m against the climate change denial movement and I know that all of us have watched that Hbomberguy video discrediting the Ben Shapiro argument against climate change; but he really did make a convincing argument.


r/askgeology • • 4d ago

Method of Formation How rapidly can a stratovolcano gain height, and what's the most recorded in a single eruption event?

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1.1k Upvotes

The picture is of Mt. Hood taken by me (and no, I don't plan on giving Mt. Hood back 😠)

I've been thinking about this question while contemplating the short mountains in Oregon comparatively to Washington, as well as the collapse of Mt. Saint Helens and Mt. Mazama.


r/askgeology • • 3d ago

ID request Found Bay of Fundy

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9 Upvotes

Hi, folks. I rockhound a bit for exercise and for the neat agates and jaspers I find along a stretch of rocky beach. The green rocks I find are so mesmerizing and I have no clue what they are. My guess is some types of jasper or chert. Am I right that copper gives these the green colouring? Are these familiar to any of you?


r/askgeology • • 4d ago

Fossil or weird ass rock?

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160 Upvotes

Chunk of flint from England, what are the arrowhead shapes? One is very defined, you can feel the grooves with your finger, one is perfectly smooth like it’s part of the rock.


r/askgeology • • 4d ago

A glacial collapse caused Nepal’s first flood. Not sure about the recent one. It surprised me to learn that the friction of the rocks under the ice caused it to melt rapidly, adding greatly to the amount of water. Do all rock slides generate that much heat?

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27 Upvotes

r/askgeology • • 4d ago

What is it?

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27 Upvotes

It was suggested on whatisit/r that I post these pics here. Found in the Huron River/Argo Dam Pond, in Ann Arbor Michigan USA. It is about 20x20 feet in diameter, in 5-6 feet of water. Hard to see unless you are directly over it and the sun is shining. Is it eroded sandstone that used to be exposed before the dam was put in and raised the water level?


r/askgeology • • 4d ago

Method of Formation Beautiful and interesting fracture lines on this piece of jasper that I found this weekend

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8 Upvotes

I would like to know about how these shapes were formed.

They remind me of dendrites as well as how frost sometimes forms on my car window.

To be clear, all of these fantastic shapes are indentations in the rock, which I called fracture lines even though I am not certain that is the correct terminology.

In the OP I called this jasper and I still think that is correct, however the few replies I had all said it was not.


r/askgeology • • 5d ago

ID request Partial Concretion Reveal

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93 Upvotes

Here is what I believe to be a concretion I found last year. Got a bunch of jokes about it being an old petrified cow patty lol. I was hesitant to open it up but I saw cut it the other day and was curious about what I’m looking at. There’s some cool veins in it, there is a ā€œgraniteā€ like looking vein but not entirely sure what it is exactly. Then there is some like fools gold appearing metallic veins in it. Couple areas that look like some quartz or crystalline structure. Just posting to learn about it if anybody knows.


r/askgeology • • 4d ago

How fast do mountain valleys accumulate sediment?

2 Upvotes

If something was laid down a thousand years ago, how deep would you expect it to be in a mountainous region similar to the Cascades?

New to Reddit, so lmk if there are particular conventions I'm missing.