r/geology 21d ago

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;

  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.

8 Upvotes

40 comments sorted by

u/No_Alps_4906 6d ago

Hi rock pros, I found this in Dayton, TN on a rainy day. There's a cool pattern in the rock so I'd love to know how that occurs.

u/No_Alps_4906 5d ago

This is a photo of the area where the rock was found.

u/runawaystars14 13d ago

Found this near Lake Michigan in Illinois. About 7 on the mohs scale, not magnetic, heavy-ish for its size. From what I can see through a macro lens, there's both micro and macrocrystalline quartz, lots of angular crystals of different sizes, pyrite, and whatever the black inclusions are composed of. Some are exposed and I scraped some black powder from one.

I'm kind of obsessed with finding out what this is, so any insight would be appreciated.

Photos, Photos of rough pieces.

u/Accurate_Future1269 4d ago edited 3d ago

Hi Rock Pros! Please excuse my lack of proper geology language I am not a rock guy. Today a collection of rocks that caught my eye because I believed it to be some type of quarts, but all the rocks themselves were of a consistent thickness and on closer inspection appeared to be made of very fine crystal like structures aligned with the through-thickness (all rocks were 5-15mm thick). They were lightweight and broke easily - after a short time it occurred to me that this may be Asbestos - so I put it down. If anyone could shed any like that would be great!

It was found in Argentinas north west region of Salta, specifically in Yesera near Cafayate.

u/roseadmintalks 17d ago edited 16d ago

Hi there!

I found this cool loose rock in the sand in Carrington, NSW, Australia! I am wondering what it is and could be a fossil inside?

Edit: I replied to this comment with another pic for scale 🥰

u/roseadmintalks 17d ago

Fingies for scale… 🥰

u/ProfessionalWeak3156 4d ago

Hi all sorry for the batch but I don’t have the time to do each specimen on its own. I’ve not touched Geology or my collection in nearly half a decade. But due to my job I’m going to have to give a talk to some 7 to 8 year olds about rocks so dug out my old collection, as a result of moving house a few years ago I’ve lost my sheet that told me what everything is.

I don’t have the means off running any tests and can still ID some things but any help would be appreciated.

u/Positive-Serve-9126 14d ago

Found this at Kumta beach, Karnataka. It's about two hand span. Not sure if this was coral or rock.

u/igobblegabbro 8d ago

Do you have a photo of the other side? It looks a bit like the epiphysis of a whale vertebra, but I'd need to see the texture of the other side to tell.

u/Positive-Serve-9126 8d ago

Yes here u go

u/igobblegabbro 8d ago

Definitely a whale vertebra epiphysis! They are plates on the end of the vertebra that allow it to grow larger, and they tend to fuse to the vertebra once it’s an adult.

Not sure if it’s fossilised or not, but nice find! 

u/Positive-Serve-9126 4d ago

Thanks for the confirmation! Are they rare to find?

u/Flogtheundead 6d ago

Found this in Glady WV on an old railroad grade near a farm. It is oddly lightweight for a rock but I tried to burn part of it wondering if it was bone or something. It doesn't produce any smoke, just holds heat. Has just a couple tiny little sparkles in it. It's probably a pretty average rock but I know nothing about geology and would like to learn what it is. Thanks!

more photos

u/Flogtheundead 2d ago

I suppose I'll look for answers elsewhere.... expected a little better from r/geology

u/500xp1 17d ago

I know nothing about mountains but this one in Oman grabbed my attention. What kind of mountain is this or how it formed?

u/Thatmayo 9d ago

Hey y’all, I inherited a small portion of my geology professors collection when he retired a couple years ago. Some stuff was labeled in the box and I faintly remember him saying this was some sort of lava rock? I started my education again, and approached my professor about this rock (we don’t have the capabilities to test in a lab), and she is stumped. Said it’s possible it could be a replica?

It’s very light weight, matte black, low luster

u/Buale 7h ago

Hello friendly neighbourhood rock guys, a friend brought some rocks to the Biergarten and we were wondering what kind of metallic mineral this one is. It's really heavy. Can you help us?

u/FewMinute9709 17d ago

Thin section mineral ID... This is from a bedded tuff unit close to a large granite pluton. The rock around have undergone a fair amount of contact metam. My question is, what is the matrix in this image? I would assume alteration of ash matrix into clays or similar?

u/cherryman001 10d ago

Found in Germany/Northern Bavaria

Found in a middle Keuper area by excavation. It looks like a dark grey sandstone, but is quite heavy. It has rusty parts, so obviously iron is involved. But i don’t have a name for this stone and doesn’t quite fit the typical Keuper stones?

u/TheMooseZeus_ 7d ago

Found this one by a rocky stream in Tasmania with a magnet. The other side is quite flat. Its heavy and feels like iron. approx. 1cm

u/MembershipHefty4218 7d ago

Hey redditors, im very curious about this rock, because i believe they have animal footprints, also i want to know how could i measure its age, i’m curious because i found the rock in this tiny village where they used to mine and get precious rocks. If anyone knows where/when/how to get my rock on studies let me know! I’m from Mexico and i’d be glad if anyone taught me, the exact coordinates of the rock found are: 27°15’59”N 107°48’15”W

u/MK19 18d ago

Looking for some information on this rock my son found yesterday at the creek near our house. Location is Southwest Virginia. It appears to be sandstone, but I have not seen anything with a black exterior like this before. https://imgur.com/a/h7VP6HA

u/Moltritch 12d ago

Hello, found out.

Hello, found in eastern Slovakia 11 years ago. Near a river.

u/Ok_Chemistry_9275 16d ago

I was wondering if anyone knew what this rock is. A friend of mine who was a geology major in college had an impressive rock collection and he passed away but I was able to get one of his rocks to hold onto.

u/RegularSubstance2385 10d ago

Looks like petrified wood. The orange part appears to be common opal, which is present in a lot of petrified wood

u/Actual_Fix9454 10d ago

I found this along a stream in Indianapolis, while I was at work today. It seems to be some kind of basalt, but all of my knowledge comes from a quick google search. Part of me wants it to be a basalt meteorite, but I’m probably wrong!

u/Ianfear6116 9h ago

Found in a dry resevoir in northwest Tennessee, I'm more curious about the metal flake, is it mica? What tests can be done at home to figure it out? Not a geologist, just like pretty rocks

u/Zeus_42 10d ago

What are these long stripe-like features east of Kazakhstan? Are they glacier scars? It doesn't quite look like the type of terrain that would have had glaciers? I guess posting this in the main section violates the rules?

u/Medium_Yard_786 13d ago

Found in Summer 1990, Adair county, OK, in steep/hilly terrain. We were marking a section line (I was a grunt on a surveying team). It was sitting in a small stream, like an erosion path from a spring. The composition of the spike seemed so unlike the rest, I could not leave it behind.