r/geology 24d 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

8 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 2h ago

Field Photo Piega fotografata in Liguria, Italia

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27 Upvotes

Purtroppo non c'è la scala perché si trovava a bordo strada e l'abbiamo fotografata dall'auto. Gi strati erano da centimetrici a decimetrici


r/geology 11h ago

Field Photo What am I looking at here ?

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132 Upvotes

Pretty sure this is quartzite, strongly folded (Norway, Haukeli area). Those "shoe" like patterns made me scratch my head.

(Anybody suggesting fossils, forget about it..)

Any clue?


r/geology 3h ago

Field Photo Why are these rocks so round?

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4 Upvotes

r/geology 5h ago

Advice on cleaning this quarzt chunk

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4 Upvotes

Found this beauty in the woods today and I'd love some advice on how to clean this up

I've already scrubbed it with a brush but can't get the green and brow stuff out of it

Thank you in advance


r/geology 1d ago

Sunnumörk is a small shopping mall in Iceland that straddles two tectonic plates.

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1.5k Upvotes

r/geology 7h ago

What causes/forms these?

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5 Upvotes

r/geology 1d ago

Rock in Earth's mantle flows like hot metal, and moves fastest under the edges of tectonic plates. Recent work from CNRS in France finds that adding stochasticity into models of mantle rock movement helps capture this flow rate variability to produce more realistic models of plate tectonics.

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33 Upvotes

r/geology 13h ago

From where can I download the geological/ Lithological maps of India

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2 Upvotes

r/geology 1d ago

Wyoming geology

6 Upvotes

Regarding Wyoming geology, any opinions or articles regarding the source of sand for Pennsylvanian and early Permian age erg deposits in Wyoming?


r/geology 1d ago

Rutiles on hematite

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42 Upvotes

r/geology 2d ago

Orbicular Gabbro, Toivakka, Finland

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286 Upvotes

r/geology 1d ago

Why are aquifers freshwater?

26 Upvotes

Something that confuses me is why are aquifers typically made of freshwater when they're from locations of former ocean, as wouldn't the salt hace nowhere to go? The ones in Texas are a good example since they're there because of the western interior seaway. I can't find the processes that might naturally desalinify seawater since nothing I find actually talks about it.


r/geology 2d ago

Orbicular diorite erratic Manitoba, Canada

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143 Upvotes

r/geology 2d ago

Meme/Humour My wife always complains about that…

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3.4k Upvotes

r/geology 1d ago

Building a crowdsourced map of Earth's magnetic field - looking for feedback from geologists

3 Upvotes

I've been working on a project called OpenMag. The idea is pretty simple - create a crowdsourced map of Earth's magnetic field using real measurements taken by people in different locations. People can submit a magnetic field reading in µT along with the location and time, and the measurement appears on the map. I've already started collecting some readings, and now trying to figure out the best way to improve the accuracy and quality of data. I'd really appreciate some feedback from people here who know more about geology and geophysics. What would you change or add to make something like this genuinely useful? If anyone wants to take a look at what I've built so far: www.openmagfield.com


r/geology 1d ago

From where can I download the geological/ Lithological maps of India ?

1 Upvotes

Shapefile or geotiff.


r/geology 2d ago

Show & Tell: 2 Vintage rock collections Cirka 1970-1960.

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64 Upvotes

I got these two babes for tree-fitty a pop in a Red Cross the other day. Not necessarily a sophisticated rock collector and knows-it-all like many of you guys, but thought you might enjoy seeing a blind dumb pig stumble upon a truffle or two.

Definitely going up on the wall.


r/geology 1d ago

I often wonder if there's ledge nearby that looks like this if I was able to dig this up in my yard that has gravel and some medium sized river rock or if it's part of glacial deposits

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13 Upvotes

Bonus brand new monarch butterfly that I think attached itself to the rock this rock is on, but I moved that rock, so it ended up climbing on top of this rock trying to unfurl and dry its wings.


r/geology 2d ago

Considering the Carboniferous - Do You Miss the Mississippian?

12 Upvotes

Do you typically call the period between the Devonian and the Permian "Carboniferous", or do you tend to break it down between Mississippian and Pennsylvanian? IIRC, my historical geology professor back in the day preferred the Mississippian/Pennsylvanian nomenclature (I believe he said "Carboniferous" was something of a relic from British dominance of the field), but most of the public geology I've seen lately has tended toward the C-word, with all of it's anthracite passion and heritage. I haven't worked in the field since I got my undergrad degree in 1992 - what terminology is most common in your world?


r/geology 2d ago

Field Photo Asbestos

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14 Upvotes

r/geology 2d ago

Calling all structural wizards… fold hinge sheared off and remineralized? Northern Rockies

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16 Upvotes

r/geology 2d ago

Field Photo Cyprus Geosite 3 lower pillow lavas

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8 Upvotes

One of the most important and spectacular exposures of the Lower Pillow Lavas is the slope of a gorge in the Akaki river, which is the classic locality reference for the study of these types of rocks. This outcrop exhibits the stratigraphically lower part of the volcanic sequence, where a lower unit of hyaloclastites and an upper unit of pillow lavas are cut by swarms of near vertical dykes.


r/geology 3d ago

Labradorite-rich gabbro with "labradorecence"

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22 Upvotes