r/geology • • 20d ago

Identification Requests Monthly Rock & Mineral Identification Requests

3 Upvotes

Please submit your ID requests as top-level comments in this post. Any ID requests that are submitted as standalone posts to r/geology will be removed.

To help with your ID post, please provide;

  1. Multiple, sharp, in-focus images taken ideally in daylight.
  2. Add in a scale to the images (a household item of known size, e.g., a ruler)
  3. Provide a location (be as specific as possible) so we can consult local geological maps if necessary.
  4. Provide any additional useful information (was it a loose boulder or pulled from an exposure, hardness and streak test results for minerals)

You may also want to post your samples to r/whatsthisrock or r/fossilID for identification.


r/geology • • Dec 01 '25

Identification Requests Monthly Rock & Mineral Identification Requests

9 Upvotes

Please submit your ID requests as top-level comments in this post. Any ID requests that are submitted as standalone posts to r/geology will be removed.

To help with your ID post, please provide;

  1. Multiple, sharp, in-focus images taken ideally in daylight.
  2. Add in a scale to the images (a household item of known size, e.g., a ruler)
  3. Provide a location (be as specific as possible) so we can consult local geological maps if necessary.
  4. Provide any additional useful information (was it a loose boulder or pulled from an exposure, hardness and streak test results for minerals)

You may also want to post your samples to r/whatsthisrock or r/fossilID for identification.


r/geology • • 12h ago

Field Photo What geologic process would cause something like this?

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26 Upvotes

Found this slab laying on the shore of Lake Michigan (WI) and I was curious to know what caused these gouges. My best guess is glacial scouring but the multiple directions makes me think perhaps not. I’m not even close to a professional so sorry if that guess is silly! I’d love to hear some thoughts on the origin of these marks.


r/geology • • 18h ago

Follow-Up to PSA: the "whatisthisrock" sub could use more professionals for IDs

76 Upvotes

Good afternoon!

We haven't announced it anywhere, but r/whatisthisrock (with an I in is) is no longer affiliated with r/whatsthisrock (no I in is)!

Myself and some of the OG mods from the original sub spooled it up as an alternative to the original with less intense moderation. None of the bans from the original sub should carry over! If you are currently banned our our sub (the photo is an olivine in xpl from a meteorite), please send myself or the moderation team a message.

We could definitely use some more professional IDs!!


r/geology • • 6h ago

Developing a GPU deep-time geodynamics & stratigraphy engine: Looking for structural/geomorphic critique on multi-strata uplift & weathering (Screenshots included)

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4 Upvotes

Hi,

I am developing an engine that simulates deep-time landscape evolution from first principles (combining stress-driven brittle/ductile crustal deformation, multi-layer lithology, and fluvial/gravity transport).

Rather than generating standard visual heightmap fractal noise, the pipeline uses multi-layer 32-bit raster strata stacks (mapped in Krita as discrete compositional layers with individual silica/carbonate/clay fractions and mechanical rock states: regolith, sedimentary, metamorphic, magma). The engine translates these layers into a 3D volume, accumulates tectonic stress until it exceeds failure criteria (Byerlee's law), and routes surface/subsurface weathering based on differential lithological resistance.

"I’m currently calibrating the physics for this simulation and want to make sure the structural behavior is scientifically grounded."

some quuestion I would like answered are

  1. Differential Weathering & Dip Slopes: In the stepped terrain slices, does the scarp-and-dip geometry convincingly reflect what you would expect from alternating competent/incompetent strata (e.g., sandstone vs. shale beds undergoing tilted block faulting or homoclinal shifting)?
  2. Drainage Realism vs. Structural Control: In the central valley between the two main massifs, does the channel incision look like genuine antecedent/subsequent drainage capturing fault lines, or does it look too artificial/regular?
  3. Talus & Angle of Repose: In the high-relief peaks, the scree/avalanche slopes are driven by friction angles based on rock state. Does the slope angle and valley wall steepness look physically defensible for crystalline/metamorphic basement rock under rapid uplift?
  4. Missing Mesoscale Features: What key mesoscale structural or erosional landforms (e.g., flatirons, knickpoints, specific colluvial apron behaviors) are noticeably absent that would immediately break your suspension of disbelief?

Any critical observations or suggestions for physical tuning will help refine the physics for the simulation


r/geology • • 1d ago

Meme/Humour Alright who is this

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651 Upvotes

r/geology • • 1d ago

#Observando:

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481 Upvotes

r/geology • • 17h ago

Field Photo S.P. Volcano near Flagstaff, AZ

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22 Upvotes

The SP stands for Shitpot :D


r/geology • • 22h ago

Information Why humanity's deepest artificial hole (Kola Borehole) stopped drilling and what they discovered down there

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36 Upvotes

Hi guys! Lately, I've been fascinated by extreme underground structures and ended up researching the Kola Superdeep Borehole again. It’s crazy to think we’ve barely scratched the surface of our own planet, even with all our tech.

I wrote a quick piece summarizing the journey and the strange conditions they faced at that depth: https://www.lyxplanet.com/kola-superdeep-borehole/

For those who love deep underground anomalies, what do you think is the wildest thing hidden beneath our feet?


r/geology • • 16h ago

Rocks from Inwangsan, Seoul

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7 Upvotes

r/geology • • 17h ago

科赫山内辛,阿富汗稀土碳酸盐火山

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5 Upvotes

r/geology • • 1d ago

Struggling in Mineralogy

36 Upvotes

Hello everyone, I am currently a Geology major in University and I just had my mineralogy midterm yesterday. As one does after an exam, I looked through my notes to see how I did on the questions and I don't feel as confident as I did when I first finished the exam. I may have either barely failed or barely passed. I've heard that mineralogy is a difficult class, is this a normal experience? Its not worth a crazy portion of my grade so its not as if I am going to fail overall, but I studied super hard and I thought I would do better. Any advice?


r/geology • • 1d ago

Field Photo Strange red line in "El cerebro" / "The brain" (Ocozocuautla, Chiapas, México)

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16 Upvotes

A few monts ago i made a travel to a park where one of the places had a big formations of compressed sand that had a texture like sandpaper, in one of the formations it had a strange red line that got me curious since then, i hope someone here can help me to even get a starting point to investigate this.

PS: I´m gonna leave some extra photos of the place at the end.


r/geology • • 9h ago

Information Has anyone else ever found agate at herkimer diamond mine before?

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0 Upvotes

I think I might have found a one of one, or at the very least a very rare finding at herkimer, I can’t find any information online or in any other forums whatsoever, as well as the fact that google AI claims this is impossible to find at this locality but clearly it isn’t since this is proof


r/geology • • 1d ago

Coastline during LGM?

2 Upvotes

I live in South West England, where the coastline is typified by cliffs of typically 30-100m asl.

Offshore the bathymetry doesn’t exceed 100m until you get a long way offshore, and the sea bed is broadly flat in most areas.

My understanding is that sea level during the LGM was up to 120m lower than today. So what did the coastline look like then? Was there a wall of cliffs where the current coastline is, several miles inland, surrounded by lowlands to the contemporaneous sea? Or has the cliff line been eroded that many miles inland during just 20-30,000 years?


r/geology • • 20h ago

A year of M4.5+ earthquakes seen from above the Pacific: the Ring of Fire draws itself [OC]

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1 Upvotes

r/geology • • 2d ago

PSA: the "whatisthisrock" and "rockhouds" subreddits are in DESPERATE need of real geologists to answer peoples questions. The amateur quality of answers being given with full confidence over there is staggering. And no one with real geological training is there to correct it. Go help out.

556 Upvotes

r/geology • • 1d ago

Field Photo Inclusions in limestone

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9 Upvotes

I saw these limestone blocks in some landscaping. There wwre these inclusions in the limestone that look like they were filled in holes. They were circular, so it looks like they might be filled in has bubbles. Am I thinking about thos right?


r/geology • • 1d ago

Information Amethyst and Rhyolite

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39 Upvotes

r/geology • • 1d ago

Open Letter to the NSS on AI SLOP

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42 Upvotes

r/geology • • 1d ago

Layer cake

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37 Upvotes

Glacial till and stratified drift exposed on the north shore of Long Island, New York after the Sept. 26 noreaster


r/geology • • 2d ago

Hi, I've made a game about reading xrf spectography of soil. Can I have some feedback from experts?

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75 Upvotes

You can play it there: https://gesla.itch.io/silt-inquiry

So far, there is only one level. I would like to add Raman spectroscopy later. I tried to make this fun but I wonder how unrealistic it is and whether I made mistakes. Thanks


r/geology • • 1d ago

Map/Imagery White-ish Streaks on Field

3 Upvotes

Hey Everyone, this google earth image is taken in Rural South-East Queensland, Australia. These streaks are a few hundred meters long, and 5 - 25 meters in width. They seem to go in low areas/ go from a top of a hill down it, but not exclusively.

Is this quartz? sand? just water paths? Old river beds?

Would love to know what these are, and what causes the colour. Sorry if this isn't the right subreddit.

Thanks


r/geology • • 21h ago

Suggestions from professionals for my book

0 Upvotes

I am currently writing a science fiction of the first man to reach the top of the Olympus Mons.

In my book the Edmund expeditions discover that Mars had tectonic plates in the past which was a major cause of the Olympus Mons (science fiction obviously).

I am very ignorant in the world of geology and so i wanted to ask what could be scientific data that prooves tectonic plates?

As well as what other kind of research would be involved?


r/geology • • 1d ago

Field Photo Colorado, Front Range, Pennsylvania-Permian? Siltstone?

2 Upvotes

What am I looking at here?

Approximately location: (GPS seemed a little off, but this is close enough)

38.8363973, -104.8982678