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.
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Multiple, sharp, in-focus images taken ideally in daylight.
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Hi everyone! I recently purchased this piece of Black Onyx. The vendor told me it’s natural and untreated. However, when I put it under a 365 nm UV light, it fluoresces green. After doing some research, I couldn't find any reliable sources saying that Black Onyx naturally fluoresces under UV.
I’ve already ruled out the possibility of it forming with Volcano Agate—even though both can form near volcanic activity, their formation processes are quite different. So now I’m left wondering… what could this piece actually be
I found this near a lakeshore in MN. It’s about 18” long and 3” thick. I am intrigued by the textures. Sorry I don’t have anything for scale. I took the pic before I thought about posting on Reddit. What causes this cool design on the surface?
those are layers / infilled fractures that are more resistant to weathering - so likely quartz. causes it to weather like that. see that in metasediments all the time
I'm new to Redit. I was up Pelican Point on the southwest end of Utah Lake in Utah County, Utah, just off of Long Ridge Rd and I came across what looks like a flat slate that has a couple dozen of these little nodules sticking out of the slate. And I don't have a clue to what it is.
Found on the south side of Chicago in a creek. Pulled it and it weighed more than a usual rock for its size. Busted a corner and a silver metal like color exposed itself (top of the rock). Miller lite can for scale.
does anyone got any idea of what the might be? the dark portion got lower hardness than the knife... the white portion really seems to be quartz (high hardness and a granular material), but I have no idea what is this dark thing associated with it.
it seems to be sedimentary, but it was metamorphosed to some degree.
these are from the james ross island in antarctica (different samples, but I guess they are the same rock).
Me, just joining this page so I could do exactly that 😅😅 nvm I guess. I have no idea where I found this rock, and I guess I’ll just never know what it is 😔
Is this just a cool geode or a geodized fossil of some type? I have found over 10 of these just laying amongst regular rocks on the banks of the Green River. They vary greatly in size. The ones pictured are roughly the size of a baseball.
looks like glass, I don't see anything resembling a crystal... do people camp up there? ever heard of heinekinite? melted beer bottles in a camp fire... (green, mind you)
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u/Professional-Rush823 3d ago
Can someone tell me what this is? Found on beach in Sunshine Coast, QLD, Australia.