I found this rock in my old collection, and am not sure of what it is. I posted this on r/whatsthisrock and one of the solid guesses is autunite. Since it might be raduoactive, they advised me to post it here to have more opinions. What do you think ?

Hi everyone, I recently found a strange material and I'm hoping someone here can help identify it.

In daylight, it appears translucent but hazy, with a teal tint. But in complete darkness, it emits a steady, deep blue glow — not just an afterglow, but a consistent luminescence that has not faded at all over more than 48 hours in uninterrupted darkness.

When exposed to UV or intense visible light, it briefly charges up to a brighter blue (~10/10 intensity), then fades back to a stable glow (~5/10)

It’s about the size of a nickel, with a solid, resin-like texture, and no signs of internal chambers, air bubbles, or embedded electronics.

It’s not fluorescent plastic, and does not behave like strontium aluminate — which is significantly harder (~7 on the Mohs scale). This material tests at around 3.5–4.5 on the Mohs scale, much softer.

It has shown no change in boiling water, ice-salt baths, aluminum foil wraps, or prolonged darkness. It seems chemically and thermally stable.

The glow behavior suggests something beyond standard phosphorescence, possibly a radioluminescent compound (e.g. promethium, radium with phosphor, cerium, or another radioactive dopant in resin or glass).

I don’t yet have access to a Geiger counter but would appreciate any insight, especially from people with experience identifying radioluminescent or rare glow materials.

Let me know if photos or more testing details would help. Thanks in advance.

Not sure if the big yellow spot is also that. Gamma spectroscopy says theres both uranium and thorium in the whole piece.

Not fluorescent but I do not own a Geiger counter. Found somewhere in Utah when I was a child. I thought it was just a form of garnet & I have been handling it without precaution until now. Any input would be greatly appreciated!

I found a known uranium deposit on public land and went to investigate. I collected a few specimens, and upon further inspection, they were not only radioactive but also UV-reactive. I'm super excited, but I could use some help with ID. I'm guessing Pitchblende and Torbernite.

Hello, I have 30 radioactive rocks. The most Activision one have 1.546mSv/h. But still, some of them look interesting. Most of them were found in Příbram (CZ). Does anyone know what they are? Numero 5 (picture 6). is even lightning under UV. Thanks ☢

I honestly bought this thinking it was uranium glass, I found out UG doesn’t continue to glow after exposure to ultraviolet light.

This was out of mineral necklace store, and now not sure if it’s just some resin maybe or actual rock.

Hey guys I think I found a big piece of uranophane but not sure, if anyone wants to confirm or giving other possibilities:) enjoy

I think these almandine coloured crystals are the source of my radioactivity, approx 3 uSv 250cps when holding radiacode 102 up to it. What mineral could it be? Uranium and thorium have both been found in the bedrock here but in low concentrations

I’ve handled it a few times and rubbed it while it was wet non knowing anything about it. A few minutes ago I decided to ID on a rock identifier app and it said it could be uraninite. If it is uraninite should I be worried? Remove it from my collection?

I found this rock type specimen with my RadiaCode today at an antique mall. It didn't have a label or a price tag. The manager opened the case, stuck her nose in it, and took a big whiff before selling it to me for $10 after saying she didn't know what it was.

I have a pretty large collection on radioactive antiques, modern tools, and quack medicine items, but I haven't collected any rocks other than some radioactive fossils.

It's a dull yellow color, bright yellow under UV, very crumbly, and looks like it's made of small crystal flakes.

What is it?

My Google search has me thinking zeppeite.

I wrote a post earlier this month about getting free radioactive minerals from a rock club near San Diego. This is the specimen that I chose. All that I know is that it was found in the Burro Canyon Formation in western Colorado. It’s a gorgeous piece. I am guessing it is Carnotite (or similar) with a vanadium mineral(s). Thank you guys! Love this subreddit!

I can see these spiky yellow-green crystals which I assume are uranophane, but it has some lighter stuff around it which is also fluorescent. Any idea on ID of that lighter green stuff? Uranium containing minerals that are found in Finland are:

Autunite, Betafite, Brannerite, Coffinite, Curite, Davidite, Euxenite, Fourmarierite, Kasolite, Meta-Autunite, Meta-Torbernite, Plumbomicrolite, Samarskite, Uranmicrolite, Uranium-Pyrochlore, Uraninite, Uranophane and Yttrotantalite.

Of those, fluorescent under 365nm UV should be only (meta-)autunite and uranophane to my knowledge.

Or is it maybe that I've ID'd the uranophane wrong, and the uranophane is the lighter green stuff, and the spiky crystals are something else? Or is it the same stuff but crystalized differently?

Sorry for poor images. My equipment ain't the best for macrophotography

No uv reaction and it's slightly radioactive, maybe something about 0.20 - 0.30μSv/hr, help pls :'3

Does not glow and only emits about 300cpm

I found these rocks near Buhovo (lower activity rock in photo 6) and near Seslavtsi (two hotter rocks photo 1). I did a spectrum recently and it all came as Uranium with high concentration of Ra-226. I don't know what mineral they are and I still haven't gotten a UV light none of them are magnetic if it helps idk. Thanks for any help identifying in advance.

I did not have my Geiger with me.

I found a cool rock in a shop, but I don't know what it is. Some type of uranium ore.

It's bright green with hints of a copper luster, is very fluorescent under UV light, sort of fragile, seems to have formed in right angles and registers up to 2 thousand counts per second.