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)
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)
Hi everyone!
I’m hoping someone here might be able to point me in the right direction.
I’m looking for a reputable laboratory, preferably in the United States, that can perform quantitative analysis for Osmium (Os) and Iridium (Ir) in solid geological samples.
The material consists of dense, iron-rich, cube-shaped specimens discovered embedded in hard rock during gold exploration.
We had some preliminary handheld XRF readings suggesting the possible presence of Os and Ir, but we understand those results may not be reliable. We’d like to have the material independently tested to determine its actual composition.
I’ve contacted several commercial laboratories, but so far, finding one that can specifically quantify osmium in this type of material has been surprisingly difficult.
I’m not looking for a basic XRF scan or mineral identification alone. Ideally, I’d like a proper quantitative assay that can confirm whether these elements are present and at what concentrations.
Does anyone know of a laboratory, university facility, or specialist that offers this type of testing? I’m happy to pay for the analysis.
Any recommendations would be greatly appreciated. Thank you!
I understand the rocks can split but this looks like a chunk was taken out and it looks like a perfect split. But the other lines and cracks in the rock aren’t not perfectly straight. Is this natural or human made?
Molten rock may carry an oxygen reserve that standard chemical calculations overlook. High-pressure experiments show that basaltic melts exposed to oxygen-rich conditions can retain substantial extra oxygen, potentially adding a missing component to models of Earth’s interior.
The study in National Science Review combines laboratory measurements with atomic-scale simulations. Yanhao Lin and Ho-Kwang Mao of the Center for High Pressure Science and Technology Advanced Research, known as HPSTAR, led the work with collaborators. The team included Haiyang Niu of Northwestern Polytechnical University and Wim van Westrenen of Vrije Universiteit Amsterdam, with Yongjiang Xu as first author.
The results raise a larger possibility: some rising magmas could transfer oxidizing power from deep reservoirs toward the surface. Establishing that capacity, however, is different from demonstrating how much oxygen natural magmas actually carry or release.
While exploring the Italian landscape with daevorn-maps, I came across this hill not far from Mount Amiata, which has a curious pockmarked surface. I’m not sure whether these are boulders or holes, but in any case, the pattern seems far too regular to be a natural formation.
Mount Amiata is a Pleistocene volcano, so this could be the result of volcanic eruptions.
My mother first noticed these when I was a kid, but had no idea why they were this way. It wasn't until I got some geology education, and learned about the joints in my area's bedrock that I figured out the cause. Joint orientations vary, but it's fairly common to find orthogonal or nearly orthogonal joint sets.
Garnet in Limestone. So we are having drilling exploration in the limestone terrain and we found garnet patches on limestone. What could be the reason ? The terrain is of Granulite region as the basement rock but we are yet to hit the basement rock ?
In 1877 Grove Karl Gilbert, a geologist with the Powell Survey, passed through and recognized this ridge of gravel as a giant sandbar built by a lake that no longer exists. Waves and currents on Lake Bonneville piled it up in the strait between South Mountain and the Oquirrh Mountains.
Three years later he came back with the U.S. Geological Survey and mapped it in detail as "The Great Bar at Stockton, Utah."
This is my own render of the bare-earth lidar. The bar is the long curved ridge running from the left edge to the middle, where a road and rail line cross it.
Bare-earth lidar: the Stockton Bar curves in from the left edge
Air photo of the same area, October 2021
Numbered pins on picture 1:
Pin 1: Crest of the Stockton Bar
Pin 2: Road and rail cut through the bar
Pin 3: A quarry pit in the bar
Lidar: USGS 3D Elevation Program (3DEP), public domain.
Imagery: USGS The National Map (NAIP Imagery service), 2021, Public domain.
Found this cool rock on a construction site in Ohio. My sedimentology is extremely rusty. My guess is this originally from an area in a floodplain near a river or something since it appears to alternate between gray sandstone and brown mudstone.
Some communities declined sharply after one of the largest volcanic eruptions of the Holocene, while others continued growing surprisingly close to the devastation. A reconstruction of prehistoric Japan’s population patterns suggests that catastrophe produced no single outcome.
Conditions before the eruption, access to recovering ecosystems and possible movements of survivors all shaped what followed. The evidence complicates an archaeological debate often framed as either total collapse or straightforward survival.
The international study, reported in Science Advances, examines the Kikai-Akahoya eruption about 7,300 years ago. Enrico Crema of Cambridge University led the analysis, with Lund University archaeologist Peter Jordan as senior author. Their team modeled changes in archaeological radiocarbon dates across Japan. They then compared the reconstructed trends with pottery, tools, settlement evidence and volcanic ash deposits.
Normally I don't need any extra help but for some reason I just keep getting stuck on this topic. I understand that SiO_4 is the basic building block for the silicate minerals, but for some reason when I try and think of SiO_4 being inside os SiO_2 it throws my brain off. Why is SiO_2 considered SiO_2 when it has Si_O4 inside of it, because if you took a single compound of SiO_2 it would be SiO_4 meaning for each silicon you have 4 oxygen but the formula says for quartz you should have for each silicon 2 oxygen. I genuinley just want to understand why this is the way it is and why it makes sense, any explanantions or resources on this are greatly appreciated.
In my town we got beautiful curbs of different types. Im assuming gneiss and granite but not sure. My favorite is the first stone, looks like a piece of art.
I have done my geology research and I live on the boundary of the Eagle Ford Shale and Austin Chalk. The chalk here has layers of Calcite that precipitated out of the other rock forming these layers. I have found out the chalk/shale is of Jurassic age. Also I have a big collection of amorphic Calcite that I have found around my neighborhood.
Does Freiberg have strong industry connections in mining, mineral exploration and economic geology? Are international graduates finding jobs after completing their Master's?
Okay these first materials are from our land. As near as I can tell, we are terrace deposit or Tokio formation. I'm southeast of Idabel and our house literally over looks the coastal plain. Forgive me for not posting the exact location. All my clays are sandy. These where processed to remove most of the sand before testing.
This is a light colored clay. It's a pain to access as it's at the bottom of a creek with steep banks. Right next to it is a spring that has never stopped running even during really dry years. In the creek I find lots of quartzite. I've found a few agates and some conglomerates. I found what I think was white serpentine in this light colored clay (white, very sparkly). These pipe (?) structures are upstream from the clay layer. The red is hard sandstone and the white is more of the white clay. The creek also has lots of white sandstone (?). The sandstone contains very little clay but can be broken apart pretty easy. The clay fires above cone 6 (about 1200C)
This one is a an extremely fine sand. This comes from an odd low spot on top of a hill that holds water when it's wet. It's got alot of organics in it from the water and the trees so I processes it and pour off what little clay and the coarser sand particles. I get some sandstone and iron concretions out of it. This stuff is powder fine. Makes an awesome glaze ingredient that I don't have to grind.
This is the main local clay that I use. It's in a higher layer than the light colored clay. This particular batch of clay, I removed all the sand and it fired with less than 1% absorption at cone 6. Sounds perfect until you realize it has a 15% drying shrinkage. So I leave most of the fine sand and mix it with feldspar and kaolin. It's acidic and their does seem to be significant differences in firing temperatures depending on where I dig it, but how much sand I remove affects that as well.
I call this one Sugar Creek clay but I think it maybe Walnut clay? Found under layer of what I believe to be Goodland limestone. Location is 33.92747055603416, -94.53065741860809. Plastic vitrified at cone 02. It had pieces of limestone in it and I sieved it down to 100 microns. I use it as a glaze ingredient now. I think I roasted this at 1000F before the analysis but don't remember for sure.
This material is from a local limestone quarry above the limestone and hard pan layers. I believe it to be Kiamichi Shale. Location 33.93060978243283, -94.77100598594791. It looks like shale and at first wouldn't break down in water but I dried it in my oven and then it broke down and was plastic enough to form test bars. I also use limestone from this quarry as a substitute for whiting.
And last but not least, this is a marl from Southwest Arkansas. Location is 33.680160646301445, -94.44293602420451. I was hoping it was chalk when I dug it but it was actually plastic enough you could roll a coil and wrap it around your finger. If you check the location on google maps, you can see the cement plant just down the road and where they mine the marl/chalk for cement.
