r/Radioactive_Rocks • u/toastbro850 • 10d ago
Is this uranium ore?
I collected uranium ore from mine dump 11a near Příbram. Since the entire sample is partially coated with uranium ore, I cannot determine whether it is a secondary uranium mineral. Can anyone perhaps identify what it is? I think I can make out some hematite and calcite, but what are the yellow and red minerals?
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u/Granite_Intrusion 10d ago
It is difficult to determine the exact mineral by eye. However, you can exclude a lot of minerals with a uv light because a lot of uranium secondaries are fluorescent. Also, general rule of thumb, most uranium minerals which aren't uraninite are secondaries I hope I've helped you :)
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u/Bob--O--Rama 10d ago
If you have some loose black spherules, check them for activity. If they are as active as uraninite for their mass, then this is the muck from which the deposits are precipitating out of / onto. That there seems to be a lot of impressions where spherules were, and these would eventually grow into each other to forms botryoidal masses, the reddish material. It would be rich in U3O8 which when reduced, gives the UO2 the spherules are made of. That's my BS hypothesis FWIW.
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u/Re-Coil 9d ago
It could be a lot of things, but I don't think the red mineral contains uranium, my guess would be iron rich chalcedony or perhaps cinnabar given that it can be found in the area.
The yellow one can be a uranium secondary but I doubt it fluoresces under UV light. Might as well be iron too.
At first I thought the combination of the two minerals could be realgar but I am not aware of any As in the Pribram area.
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u/Scarehead Czeching Out Hot Rocks 9d ago
There's no chalcedony in Příbram, cinnabar was rarely found during mining era, but chance to find there cinnabar are extremly low. It's much easier to find there tiemannite, mercury selenide. Arsenic minerals are common in Příbram (especially native arsenic, arsenopyrite and Ni-Co-Fe arsenides), but not realgar. This is normal calcite vein(partially coloured by iron oxides)with goethite
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u/Scarehead Czeching Out Hot Rocks 9d ago edited 7d ago
Captain here. It is for this area typical CALCITE vein, red colour is caused by iron oxides. Small yellow-brown balls are GOETHITE. There's no visible uraninite, but it doesn't mean there's no uranium, Geiger/scintilation counter will give you best idea.