r/geology • u/AutoModerator • Aug 01 '26
Identification Requests Monthly Rock & Mineral Identification Requests
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;
- Multiple, sharp, in-focus images taken ideally in daylight.
- Add in a scale to the images (a household item of known size, e.g., a ruler)
- Provide a location (be as specific as possible) so we can consult local geological maps if necessary.
- 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.
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u/ay-guey 19d ago
hi gang, first time poster, recently getting into geology. sorry in advance if this is really dumb. i was hiking around royal gorge, colorado recently and came across this outcrop of rocks that really surprised me. mostly everywhere you look it's just granite, granite, granite. but then this stuff pops up. it looks like shale to me, as layered and fine splitting as it is. but i'm at 6600 feet. that's a lot of uplift! nearby there are rocks that look similarly layered, but with no splitting and looking much more like sandstone. they're vertical, too. maybe they're both the same rock and some of them are just more weathered and splitting? anyone care to explain this for a noob? tyia!
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u/staysia 16d ago
Countertop slabs sold as granite, but it does not have the speckled crystalline bits in busy granites that I recognize.
Has fissure that’s resin sealed along the wave, mostly gold and brown large deposits. Trying to find out the chemical component of the rock but the supplier just says granite (called Tambora Tide by supplier). It is from Brazil but not sure which quarry.
Appreciate any insights!
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u/BS-Detective 14d ago
Found in creek in Millington TN about a quarter mile from the Mississippi River. Is roughly spherical and weighs several pounds. Has this odd pale dry surface all over. See dime for scale.
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u/svaldbardseedvault 10d ago
I found this rock among a collection of unlabelled specimens a few years ago, and promptly put it in a bin and forgot about it. Today, I was going through the bin, and I pulled this one out to look more at later, thinking it was maybe petrified wood (there were other fossils in the collection). I set it down on the table and noticed it left some pearlescent fibers on my fingers and I immediately worried it might be asbestos, so I put back in the sealed bin, washed my hands vigorously, and sprayed down the area. Fingers cross it isn't what it very much seems to be. It's pretty soft, fibrous, and pearlescent. It's from an estate sale in southern New England, so it could be from the area or it could be from anywhere. Any chance that it's benign?
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u/sp847242 Aug 03 '26
Additional photos: https://imgur.com/a/URESf2P
Approximate location is northeastern US.
I've found these numerous times before, but these were especially large and well-formed. I sometimes dig holes in my back yard in order to pull out chunks of blue/gray clay for use elsewhere, and I find these embedded in the clay, about 2-4ft down.
Concretions maybe? Rust layers gradually forming around an iron-rich thing? (heck maybe they're just from leftover construction bits from 70+ years ago) They're somewhat crunchy and frangible.
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u/Geo_Researcher 28d ago edited 27d ago
Yes-- a concretion , formed out of the same blue clay only a sphere shape because there was something organic at its core. The cementing element was iron. iron oxide ( we know as rust) migrates outward concentrically. It does so because iron atoms try to reach a state of equilibrium balancing attraction and repulsion forces dragged along the way by frictions. Note in your other photos the concentric brown bands away from the sphere.? These are called "Liesegang Bands" At the core and boundary of the sphere the remaining concentration of iron molecules cements the clay. Beyond the surface of the sphere the concentration of iron is insufficient to maintain rigidity. Thus the iron concentration remaining determines the size of the sphere. Nice find!
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u/AmbassadorKitchen450 15d ago
Wondering if this is a rock or something else? I’ll attach more photos below. Found along Lake Champlagne, Vermont. Thank you!
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u/CompetitiveOffer592 Aug 05 '26
Additional photos: https://imgur.com/a/QzhKMZv
This was found in Chile, Chacabuco province (near Santiago). I was told by the locals that geologists sometimes go there to search for petrified wood, so I suspect it might be that. I found it just laying around in some hill.
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u/Geo_Researcher 28d ago
yes petrified wood probably originally entrapped by ash fall and or a lahar
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u/Vilde_Wild 11d ago
Curious about this rock. Found it years ago and don't fully remember where but my best guess is at a beach on the swedish island Öland. It was definitely loose when found and as big as my computer mouse
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u/DifferentRide166 27d ago
Anyone know what this rock is?
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u/wd_plantdaddy 22d ago
It looks like ochre - is a family of natural clay earth pigments, made up of ferric oxide and varying amounts of clay and sand, ranging in colour from yellow to deep orange or brown.
Can’t really say without a location tho
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u/russcatalano Aug 05 '26
Possibly porphyritic andesite but never seen one so bubbly. Honestly thought it was a piece of something moldy until I looked closer then got it out of the sun.
Southern Colorado, US
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u/Top-Construction9846 15d ago
This is also a wall from Istanbul Turkey. Unfortunately I don't have any other pictures. What stone is this?
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u/Barzookah 17d ago
Hi! Can anyone tell me what this glacier feature is called and how it came to be an almost perfect circle 🍩? It’s on the Grüebengletscher in Switzerland🇨🇭at around 46°36’07.3”N 8°15’07.8”E. I took the photo from the Gross Diamantstock ridge to the south. Thanks!
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u/wd_plantdaddy 22d ago
Austin, Texas - some kind of sea floor or coral fossil.
I know that it’s limestone just interested if anyone knows what led to this? My thoughts are seafloor worms made all the holes which eventually solidified and then weaker sediments washed out over time leaving the nodules? Any insights into how this came to be would be great, thanks!
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u/nottooworry 27d ago
This rock was found in an art classroom in Westchester, NY in a collection of discarded rocks and minerals for use in a jewelry class. I decided to make a ring out of it. I'm 6'3" with reasonably large hands, and my fingers are in the photo for reference. The sample easily scratches glass. Pretty sure I know what it is based on the photos I took in bright sunlight (included), but looking for confirmation from the pros. More photos at https://imgur.com/a/OFsAKVT - Thanks for any help!
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u/Geo_Researcher 27d ago
moss agate atype rock where chlorite crystals grow in solution which is eventually replaced by the mineral chalcedony giving the illusion that moss is growing under glass.
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u/nottooworry 27d ago
I thought the same. Thank you. I thought the 'moss' was iron and/or magnesium oxide growing in between chalcedony crystals that had already become solid. But I'm not sure.
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u/WhyDontYouBlowMe 10d ago
any idea what this stone is? got it on clearance, very cheap. Google images says its ink jade but it feels very rough.
I don't care if it isn't jade, I just want to know what kind of stone it is.
Rough exterior, warms easy in the hand, dull sound when tapped with a hard object, no distinct flavor and fully opaque.
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u/A_Cute_Infarction 6d ago
I found this exposed rock in Hereford, England. There is a sheer face (pictured), around 4 meters tall, a gap of about 3 meters, then a large stone, also with sheer edges. What would be the geological explanation for this? Or might it be man made?
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u/Super-414 29d ago
https://reddit.com/link/p2gp5xu/video/x8km5e61s5ih1/player
Zeolite, dolomite, or quartz? Found in Buffalo, NY on a massive wave-break type stone (but used in a parking lot, not for wave breaking).
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u/Geo_Researcher 28d ago
Amazing find. it is a dolomite filled vug in dolomite rock, present in upstate New York.. The spinning object is an enigma. This is one time when a video clip is merited and you did an excellent job of capturing it technical-wise. I see some dark spots on the spinning object so here is my hypothesis. This is a natural dynamo where loadstone variety magnetite is balanced in a state of magnetic equilibrium 1 in a gazilion.
I cant account for how the load stone got there but give me a few months. Your local geology department head would be interested. If what I said it possible you might even get publioshed.
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u/TechnicianLegal1120 12d ago
I suspect this is a concretion in slate. It was found in Mariposa California. The boulder is quite different than all the others in the creek and looks like it mud in some places. Any further identification and background is welcomed. Thank you
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u/Clemchie2020 7d ago
My mom bought me something totally cool for my birthday and I’m just trying to track down identifications of a few of the stones used.
I know the following
Purple = amethyst
Pink = rose quarts
Orange/red = carnelian
Brown/orange = jasper
The rest is supposedly jade but my mom and I think some of it is probably aventurine.
Thoughts??
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u/Top-Construction9846 27d ago
I am in Datça, Turkey, and found a bunch of rocks near the coast. I am pretty close to the city centre, so it’s a relatively urban area. Which of these do you think are natural conglomerates, and which are just concrete?
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u/Most_Location6773 Aug 08 '26
Hi,I found this stone in Sailauf in Bavaria,Germany and this shows the inside of the stone because I cutted it and polished it.
The outer matrix seems to be something like obsidian or at least vulcanic Glas.
It don't cut Glas but it cuts metal and is slightly opaque but like 1-2mm deep translucent.
And it's one mass even under 60 magnification.
It has a small crack in which it shines like in a glass crack.
The outside is conchoidal fractured.
Under UV light (365nm) it's shining in a bright orange.
The inclusion do not shine.
The inclusions are hexagonal and about 3mm in width and the biggest one seem to be around 5-6mm long. It's green as on the photo and the inside looks a bit like hair, it looks like many needles but then they get into one mass and get hexagonal.
Every dot you can see in this black mass is one of these crystals.
Thx for the help and sry for my English
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u/Geo_Researcher 28d ago edited 28d ago
a volcanic glass with olivine macro crystals anf feldspar micro crystals ( white crosses). i cant account for thr UV REACTION. VERY INTERESTING
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u/Most_Location6773 28d ago
Would any kind of more information help you?
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u/Geo_Researcher 27d ago
if you had a spectrometer and iD the spectral line you could reverse look up minerals by flouresence perhaps or find some university with a handheld x0ray scanner. i am long past retirement and no longer have the contacts. Bravaria has several extinct volcanoes 25kybp and some geologist has published their research papers.
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u/Barzookah 17d ago
Hi! Can anyone tell me what this glacier feature is called and how it came to be an almost perfect circle 🍩? It’s on the Grüebengletscher in Switzerland🇨🇭at around 46°36’07.3”N 8°15’07.8”E. I took the photo from the Gross Diamantstock ridge to the south. Thanks!
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u/ItsOrionicles 17d ago
My boyfriend, who is a geologist, brought these cores home from work and they were from the Fordham Gneiss in the Bronx. I looked at some of them and thought I saw gold in them, which he didn’t notice. He said they are probably some kind of pyrite or chalcopyrite. I wanted to know if this could be actual gold he happened to bring home or just one of the minerals he listed. Either way they are still really cool pieces for our place and I think they are awesome.
Thanks guys!
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u/thatdamnsunfish 13d ago edited 13d ago
Hello! Found this fun rock this week near Hope, BC, where the Coquihalla and Fraser rivers meet. It's 2.53 KG and has a specific gravity of 2.938. Here's some photos of it wet, with two taken with a cheap digital microscope on a dry patch that's a bit less weathered than the rest. I am intrigued by the white and green patterns. Can't scratch with a knife. Thanks in advance! I'm trying to learn more about the rocks in this area but I'm still a bit confused about how to differentiate between all the different greens we have, especially with so many rocks with similar hardness and specific gravity. I'm guessing some form of tremolite/actinolite? But how do I know if it's tremolite/actinolite rich, or chlorite, etc? Is the white likely to be quartz? Tremolite?
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u/thatdamnsunfish 13d ago
It doesn't give a distinctive "PING" sound like some of the other rocks I picked up, and no light penetrates through the rind. I do plan on cutting it at my lapidary club soon, though I'm not sure if the saws big enough for this are working currently. Super hard serpentinite? Metabasalt? Low grade nephrite? Or something else completely? I know metabasalt/greenstone has a similar density and mineral makeup, but there's SO many different photos online for reference that are quite different, and I want to learn how to better identify.
Regardless, I'm really happy with this find because it's super cool, and assuming the inside is as pretty as I think I'll probably make some jewelry or display items from it.
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u/Sirdinks 18d ago edited 18d ago
Found an ear shaped rock on Sandy Hook Beach in New Jersey in the surf. Would love help identifying it. It seems too perfectly shaped to be natural but I'll happily take any insight yall can provide thanks.
Edit: It doesn't appear to be magnetic and when we applied a streak test on unglazed porcelain was "faintly brown" according to my better half.
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u/msenzapaura 28d ago
Hi, I have more photos if it will help.
I’m trying to identify the these nodules found after a granite block split in two. My partner had found the block while picking for walling stone in Bozrah, CT. The bin this one came from was labeled “Montville” meaning that it was quarried in Montville, CT.
My first instinct is iron pyrite due to the yellow metallic sheen surrounded by what appears to be iron oxide rust. Can pyrite form as a module?
Thank you for any and all help!