Today I set out to explore a forgotten site in Czechia, a uranium exploration site from the 1950s. No samples from that time have survived, but the effort to obtain some documentation samples for research was successful.
Up to 20 cm(8") thick uraninite vein in abandoned uranium mine in the Czech republic with doserates strongly exceeding 1 mSv/h with radiacode. It was almost pure uraninite with small amount of pyrite and some recently formed secondaries.
@Radioactive Minerals CZ
All the great hot rocks in this group gave me an idea to compare one of my hottest rocks with two very popular radiation detectors. Tested subject is massive uraninite from Příbram area(my collection, self-collected). Tested counters were radiacode 103g and legendary ludlum model 3 with 44-9 probe, famous mica window.
Radiacode: display shows maxed dose rate (1 mSv/h) and 1,8 millions CPM. In the app, doserate goes up to 1,5 mSv/h
Ludlum model 3: while this counter shows "just" 300 000 cpm due to lower sensitivity, it also shows aproximately 300 mR/h(extrapolated to the lowest scale "100x only" ending at 200mR/h), which means 3 uSv/h.
Ludlum clearly shows much less cpm, because geiger counter is less sensitive than scintilation detector, but ludlum shows higher doserate, because it's not energy compensated and also detects alpha and beta radiation - with shielding results would be similar.
Note: the dose rate values are still only approximate, they only apply to a small area on the surface of the stone, they do not refer to the dose absorbed by the observer.
Today's wanderings around one of the lesser-known Czech localities led to the discovery of a rather nice sample of autunite.
An extreme example of radioactive mineral collecting. Two years ago I discovered a uranium ore vein outcrop in a field, which I was able to uncover to a depth of about 5 feet/meter and a half. This is the upper weathered layer of a richly ore-rich uranium vein about 1 foot/30 cm thick. The material contained a diverse assemblage of uranium minerals such as phosphuranylite, uranophane, autunite, torbernite etc.
I recently showed a larger sample of uranium ore from a rich uranium vein outcrop in the Czech republic. Here are a few more samples and a full crate of catches. The samples contain mostly phosfuranylite, uranophane, autunit, torbernite and limonitized uranium micas. This was a really exciting place with large chunks of uranium minerals, but they are still waiting to be cleaned up. A few short videos from the site are available on my social media (mainly FB and IG). Radioactive Minerals CZ Facebook
Large piece of uranium ore - gummite sample from uranium vein outcrop in the Czech republic. It contains autunite, torbernite, phosphuranylite, probably uranophane and limonitized uranium micas, activity with RC few hundreds uSv/h.
No contest, I was just mentioning that 800 uSv/h for the Příbram ore is nothing exceptional, which was questioned, so just to show that I wasn't exaggerating. The dose rate for this sample per contact is 1200 uSv/h(1.5 millions CPM with RC103g), but that's not a record holder either. Good luck hunting radioactive rocks, everyone!
Metatorbernite from Předbořice mine, Czech republic, self-collected in 2022.
Just another decent botryoidal uraninite from my country, Czech republic, Příbram uranium district.