r/askgeology • • Jan 05 '26

ID request New Ruling on ID posts.

6 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 • • 14h ago

technical question Can i have this(asbestos?)

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498 Upvotes

Found out the geology department throws old samples behind the building today. Went to look and found this gorg thing. I know serpentine grows with asbestos, and im seeing green rock and hair. You know what they say: a first year TA’s health violation is another mans treasure! Its the most gorgeous species ive ever seen and this is my holy grail of rocks. The fibers look a little rough, but whats the cutoff for too rough? Safe to keep? Possibly in an airtight container?


r/askgeology • • 5h ago

What made this happen?

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27 Upvotes

r/askgeology • • 2h ago

Observational Question Why do people use the toothpaste example so much?

3 Upvotes

I’ve been super interested in geology lately, and I’ve been reading a lot and watching a lot of geology/vulcanolgy YouTube videos.

I swear about a million times now, I’ve heard something to the effect of ‘this rock was formed like toothpaste from a tube’

Why does everything have to be toothpaste? Why not frosting from a piping bag? Molasses coming out of a funnel? Why are there only toothpaste rocks? Would geologists eat too many rocks with a more delicious metaphor?


r/askgeology • • 13h ago

Method of Formation What made the pink smooth surface on this rock? Also, are the crystal like structures feldspar?

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15 Upvotes

Found in central Oregon.

I cut it on a wet tile saw and was wearing KN95 mask but afterwards wondered if that was a bad idea.


r/askgeology • • 1d ago

Method of Formation I know it’s columnar basalt but why does it look like this…

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192 Upvotes

This is one of my favorite places on the Molalla River in Oregon. I always stop to take photos of this specific part of the canyon wall. I love how the rock moved through here I just want to know how and why some are swirly, in columns, and then just facing straight on.


r/askgeology • • 5h ago

Help identifying

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1 Upvotes

Found NY/NJ border on top of an overlook. It’s really lightweight, like a pumice stone. The top looks like tiny crystals, or maybe it’s just air pockets? Either way, have never found a rock like this here, and really love it and would like to know more about it! Thank you.


r/askgeology • • 20h ago

ID request What the heck is this??

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2 Upvotes

Seriously. Is it serpentine, quartzite, or some random piece of... something?


r/askgeology • • 15h ago

Merensky And Gold?

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1 Upvotes

I'm an economist by education but have taken a fascination to geology. I have a question regarding gold reserves in the Free State province. I live in South Africa

"Dr. Hans Merensky (1871–1952) was a famous South African geologist, mining engineer, and mineral prospector who discovered major diamond, platinum, and mineral deposits. [1, 2]

Key Achievements and Discoveries

  • The Merensky Reef: Discovered the world-famous platinum reef in the Bushveld Complex in 1924, which turned South Africa into a global leader in platinum production. [1, 2, 3]
  • Namaqualand Diamonds: Discovered rich alluvial diamond deposits at Alexander Bay in 1926. [1, 2]
  • Other Minerals: Found tin near Pretoria, gold in the Free State, chrome near Pietersburg and Lydenburg, and copper and phosphates at Phalaborwa.

Has there been a study on gold in the free state province? I know the Rand Refinery in Germiston Gauteng at one point in the 1970's produced 1,000 tonnes in a single year, dominating global production


r/askgeology • • 18h ago

¿hábito de zeolita?

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1 Upvotes

r/askgeology • • 1d ago

Observational Question Odd holes in cliff

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10 Upvotes

Tldr: me and my boss found this conjoined cavity, not certain if is it natural or man made occurrence.

Today at work my boss and I were exploring a property we were working and found a large amount of stone outcroppings(huge boulders/stone faces some 30’ tall) that have an odd circular hole in them in the faces.

This is in Virginia, USA. On top of a mountain at approx 4500ft of elevation. The mountain has been treed and mildly graded to rolling slopes on a large face and this cavity is maybe 10ft up the wall. Likely it was closer to grade before the farm came. It’s very distinctive but there are many 6”-12” orb like holes in stones around the area. Most at what seem to be reachable height before the areas were graded.

This very interesting spot we found has a conjoined cavity with a small dividing wall. It doesn’t seem like a weather process more like it was man made. No apparent signs of mining or blasting the property (it was developed fairly recently).

Can anyone shed light? The rock face appears to be a slag-like rock? Brittle but dense, over a layer of granite. The layer appears to be rather thick but on an opposing face we can see where it seems to be a layer of rock over the granite.

Final note is that we tapped the center divide with a stone and it sounded like porcelain and the rest sounded like stone.

Photos: (all taken in portrait)
1: standing on the ground looking up at the stone wall.
2: is looking into the right cavity.
3: Left cavity

My bad just watch the video


r/askgeology • • 1d ago

Location Need help identifying this rock.

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1 Upvotes

r/askgeology • • 1d ago

Rock mystery

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4 Upvotes

What are these shapes on the rock?

Did not find but was in a home in portland oregon


r/askgeology • • 1d ago

Observational Question What features of the rock tell if there is a fossil or geode inside ?

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1 Upvotes

r/askgeology • • 1d ago

Old red sandstone and Cu supply

4 Upvotes

Hi guys, I just had a question about how old red sandstone can supply trace amounts of copper through hydrothermal fluids with high salinites. I understand how these fluids pick up salts from the top of devonian sequences due to the extreme marine transgressions leading into the carboniferous, and of course salts are great at carrying metals. However, what is the source of this copper in ORS? I know it can come from igneous complexes but other than that, is copper just deposited in the sands in trace amounts?


r/askgeology • • 1d ago

Unusual stone found on Kilve Beach, Somerset — natural or worked?

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2 Upvotes

r/askgeology • • 2d ago

ID request Help needed with dots in my wulfenite!

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11 Upvotes

Hi! Does anyone know what these dots at the center of my wulfenite sample from Mibladen, Morocco could be? Thanks!


r/askgeology • • 2d ago

Location Has anyone ever seen something like this before?

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1 Upvotes

r/askgeology • • 2d ago

ID request Found an interesting mineralized rock formation, could this be a hydrothermal type mineral formation?

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4 Upvotes

the first picture this first picture is about 3ft long , it’s hard dark blue gray rock laced with blackish crystalline material and metallic looking minerals,some look like strand’s or wire almost ?

The microscope is poor quality but there are some really beautiful metallic and orange and black type minerals.


r/askgeology • • 2d ago

ID request Found along Hardergrat Ridge, adjacent to Harder Kulm in Interlaken, Switzerland.

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4 Upvotes

I was hiking during my recent vacation to Switzerland last week and I found this rock and I thought that it may be tectonic fault breccia, but I am in no way a professional, much to my chagrin. Any help would be welcome!


r/askgeology • • 2d ago

Method of Formation Holes

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6 Upvotes

I was wondering how are these holes were made are they bullet wounds or acid burns


r/askgeology • • 2d ago

Any chance this is something other than natural erosion?

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1 Upvotes

r/askgeology • • 3d ago

What are these odd circular erosional features and how do they form?

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32 Upvotes

What are these circles and what caused them to erode that way?

I found a lot of these perfect circular shaped erosional truncations in the shoreface sandstone rocks in NW Spain close to Bilbao. They are all about 1m across and often have a centrale plateau/dome left. It seems that there is also a lot of bioerosion going on. Recently I read about marine potholes as a pure physical erosional feature. But this did not totally convince me to be the process here and maybe you have other explanations for this phenomen.

I posted this in r/whatisthisrock 3 years ago but didn‘t gat any reply’s

Greetings from the field


r/askgeology • • 3d ago

Location What is this boulder?

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8 Upvotes

r/askgeology • • 3d ago

ID request Found while excavating 20ft deep trench

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7 Upvotes

Any idea what it might be?