| T O P I C R E V I E W |
| FBSMatt |
Posted - 05/27/2020 : 07:07:13
I collected some rocks for near an old lead and iron ore mine in Ireland. I think this is iron ore, but I gives quite I high reading. What exactly is this?
Video: https://drive.google.com/file/d/1iTVkvNS0aKlEY4ObKvkeAuvkfcgST_Dl/view?usp=drivesdk |
| 3 L A T E S T R E P L I E S (Newest First) |
| kotarak |
Posted - 05/28/2020 : 06:16:44
750 000 CPM is nothing to be underestimated - that's around 2+ mSv! Especially if you don't carry a counter and you stand in one spot over this area for a prolonged time or even worse - disturb the dust and get it airborne. I wouldn't imagine it was an actual sizeable fuel fragment - it should have saturated the GM tube immediately. Most likely it was either a single hot particle or a cluster of such. Fission byproducts like Sr-90 or Cs-137 can produce quite high readings and half-life of these is around 30 years. |
| FBSMatt |
Posted - 05/27/2020 : 17:35:33
Interesting. I was never worried about it, I called it a high reading because it is quite high compared to other things I found. I fount that the reading from this sample and a thorium welding rod are quite similar. Nothing seemed to show up under UV light. I have a rock that was reading over 5000cpm, I found it in the same area around the mine, I’ll make a video of that once I can get to my studio complex. The highest reading that came out of nowhere was when we were filming a bit in the Chernobyl exclusion zone, near where some turbine parts are dumped (west of NSC), the associate we were with (who we also treated as an AD) was Misha Teslenko. We were setting up some cameras, Misha walks near what seemed to be a slightly lighter colored area of soil, and the two meters he was carrying have seizures. I take my 600+ nearer to the the area, about 3 inches for the soil reads around 7000cpm but this one part of the area shot to over 750,000cpm! I can only imagine this being a fragment of fuel or something, as other parts or block 4 were in that zone. The number I gave must of been from around 6-10 inches as we all stepped back a bit, that’s what surprised me as I can get a higher number from simply Am241 but it has to be really close to the window. |
| kotarak |
Posted - 05/27/2020 : 08:24:14
It is really hard to tell from the video what mineral is this but here are a few comments:
-don't me alarmed by "Medium/High" alert flashing on the GQ counters - these warnings are very conservative and pertain mainly to environmental readings/dosimetry rather than surveying activity of minerals - look at the CPM!
- 170-200 cpm for a random piece of rock/ore is hardly a "high reading". For example, a random piece of granite rock my kids found during a casual walk in the local park was reading 220-230 cpm.
- Uranium is more abundant (2.4ppm) in the Earth's crust than gold, silver and tin while thorium is almost as abundant (12ppm) as lead and cobalt so it is normal to see some activity in most metal ores.
- Uranium is often present near places where other heavy metals are found - like lead (Lead btw is the end of the Uranium decay chain) and "likes" the company or rare earth elements.
- it is likely that your rock has some trace inclusions of uraninite (UO2) - it is a black in color mineral
- I think I see some yellowish inclusions (hard to see on the video) but these could be secondary uranium minerals (like autunite or carnotite) - some of these are fluorescent under UV light - check it with a black light - autunite and andersonite are especially bright greeen/yellow under black light.
- it is likely that your rock includes only traces or either uranium or thorium (again 170-200 cpm is really nothing, considering the size of this rock).
For an example, most of uranium mineral samples in my collection are with an activity anywhere between 3000 cpm for the really low grade to all the way to 350 000+ CPM (torbernite, gummite). |
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