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Improving Mindat.orgToxicity
28th Jun 2013 15:02 UTCcascaillou
28th Jun 2013 18:14 UTCOwen Lewis
I keep my Clerici fluid in the same cupboard as my whisky glass (where little fingers can't reach them):)-D
N.B in byegone days, it has been sold as a depiliatory, a treatment for syphilis and still (in some countries) iis sold as a domestic pest killer. Nagging wives and irritating children take note...
28th Jun 2013 19:49 UTCSpencer Ivan Mather
Spencer.
28th Jun 2013 21:27 UTCAlfredo Petrov Manager
Three simple rules will eliminate all potential toxicity problems from mineral collections:
1) Live in a well ventilated home. (And there are several other good health reasons for doing so, quite apart from your minerals.)
2) Avoid activities that generate fine dust; wear a respirator if you must be exposed to dust. (And that advice includes wood dust, other organic dusts, road dust, and the contents of your vacuum cleaner, not just minerals.)
3) Wash your hands before touching food. (Good advice after gardening and lots of other daily activities, not just after playing with our rocks.)
Obey these three simple rules, which all sensible people already do anyway, and the potential toxicity of some mineral species will be entirely irrelevant to mineral collectors.
:)-D
28th Jun 2013 21:48 UTCOwen Lewis
28th Jun 2013 22:09 UTCAlfredo Petrov Manager
28th Jun 2013 22:25 UTCOwen Lewis
28th Jun 2013 23:07 UTCColin Robinson
Of course, if we did that what on earth would we do with all the unemployed health and safety advisors?
29th Jun 2013 09:14 UTCJan Hartmann
4. ALWAYS declare these minerals on the Jousi box - even in your own collection. In case something happens unaware persons should know what kind of mineral they're dealing with.
90% of my collection includes U, As, Tl or Hg-bearing minerals. The only injury I got yet was a deep cut by a large chunk of Obsidian.
29th Jun 2013 09:28 UTCRalph S Bottrill 🌟 Manager
29th Jun 2013 09:56 UTCJan Hartmann
29th Jun 2013 13:39 UTCcascaillou
29th Jun 2013 16:50 UTCRalph S Bottrill 🌟 Manager
29th Jun 2013 17:32 UTCJan Hartmann
If it's really that bad in the US the (horrifying) prices on radioactive specimens would make sense.
29th Jun 2013 20:33 UTCReiner Mielke Expert
29th Jun 2013 22:05 UTCDavid Garske
I've also recently read that manmade sources of radioactivity are hundreds of times hotter than the natural ones.
For reality-how many times have you heard that a mineral collector died from being exposed to his/her collection? It's a lot more dangerous to drive to a mineral locality than it is to possess the specimens.
Dave
29th Jun 2013 22:23 UTCJohn Sobolewski Expert
There is a good reason that the OSH people drive you nuts. It is the job of all bureaucrats to worry about us, drive us nuts, establish ever changing rules about things they know little about, and write reports about the extreme dangers they have found and the great job they are doing in mitigating those perceived dangers. It gives them a power trip high and helps protect their jobs.
The more bureacrats politicians create, the less freedon we all have. Big brother know best. John S.
29th Jun 2013 23:20 UTCOwen Lewis
29th Jun 2013 23:50 UTCRalph S Bottrill 🌟 Manager
And they repeat this nonsense about one asbestos fibre being enough to kill you, the I keep telling them that studies show we adults all have thousands of such fibres in our lungs already so we must all be walking dead!
30th Jun 2013 01:02 UTCAlfredo Petrov Manager
:)-D
30th Jun 2013 10:15 UTCJan Hartmann
A friend of mine has a 1 kg chunk of pure Uraninite from Shinkolobwe and this one goes up to 2,5 mSv/h - just Beta+Gamma decay!! The average annual dose in Germany is around 2 mSv.
The maximum dose I measured with several Geiger counters (even a lab one) was 1,5 mSv/h B+G on a 2 kg Pitchblende with 75% host rock.
20 mSv are the upper limit for persons who work with radioactivity. That's also the dose of a full-body CT.
You're right, man made radioactivity is much higher but speaking of "pathetically weak radiation" is just plain wrong. You also can't inhale particles of these medical devices.
30th Jun 2013 12:18 UTCReiner Mielke Expert
30th Jun 2013 13:08 UTCJan Hartmann
But: unboxing, making pictures, doing some measurements and putting a specimen into a Jousi box take some time. Not much but if you specifically collect U-minerals - like I do - you're exposed to quite some radiation over time. Especially if you're looking for secondary formed minerals under a binocular as well.
Anyway, if this is done and the specimen is in a box behind glass and maybe some lead the exposition to radiation is not forgettable but very small compared to the above mentioned doses. It's ridiculously low compared to man made radiation as well but no one keeps a 1 kg Co-60 source in his personal collection for years.
30th Jun 2013 18:30 UTCDon Saathoff Expert
SO, I don't lick 'em, I don't snort 'em, I wash my hands after playing with 'em and I'll live to find more!!!
"Don't worry, be happy!!"
Don S. "and my cows don't glow in the dark!!"
30th Jun 2013 18:49 UTCJan Hartmann
I got around 3 kg of Uranium minerals from the DRC on display and some more kilos of other localities in a box on my balcony as well.
30th Jun 2013 22:18 UTCRock Currier Expert
1st Jul 2013 01:44 UTCReiner Mielke Expert
1st Jul 2013 02:45 UTCRick Dalrymple Expert
News paper article from 1954
1st Jul 2013 20:58 UTCcascaillou
4th Jul 2013 12:39 UTCRock Currier Expert
Can you point out a single case where anyone has been harmed by a mineral collection? Are there not vastly many other things in the world to worry about than one that has never caused anyone any harm that we know about?
4th Jul 2013 14:19 UTCcascaillou
Anyway, considering scientists have defined exposure limits, and considering that very simple measures will keep you safe (thus allowing you to collect whatever you want serenely), why would one choose to ignore these knowingly...
4th Jul 2013 14:29 UTCJoel Dyer
Google for arkisto.gtk.fi/2012/60_2012.pdf to get the functioning document link.
4th Jul 2013 14:42 UTCOwen Lewis
The policemen sighed and responded, "But sir, there are *no* elephants in Piccadilly, especially at 3 a.m.".
Still clicking his fingers, the man grinned and replied, " Yes, I know, It;s soooo efficient, isn't it?"
4th Jul 2013 14:59 UTCcascaillou
Whenever you cross a road, a car may accidentally hit you. What should you do about it?
1)Ignore the cars
2)Stay home to avoid cars
3)Look left and right before crossing road
4th Jul 2013 15:16 UTCJolyon Ralph Founder
To try to brush it under the carpet and say it's not significant is not good idea.
Most minerals can be kept safely, and assuming you follow the usual precautions of avoiding breathing mineral dust and washing your hands after handling minerals, you'll be fine.
There is much paranoia and misinformation around (for example, cinnabar is essentially non-toxic). Malachite, on the other hand, is much more poisonus than cinnabar, as it's much easier to absorb the heavy metal from a carbonate than a sulfide. Still, it's not really worth worrying about if you wash your hands after handling it.
BUT...
There are certain classes of minerals that do need concern.
Radioactive minerals need special handling and care. Small samples are generally safe to own IF you can ensure you avoid any chance of breathing in the dust. Sealed in boxes is ideal. Larger pieces can generate radon inside the box, but this is almost certainly less harmful in long term than the risk of dust.
Certain asbestiform minerals should also be treated with the greatest of respect. Although the risks of having a single specimen in your collection are low, again, it is better to be safe and again keep them boxed and sealed.
There are many other types of collections that need careful conservaition for similar reasons. Collectors of old toy soldiers have to deal with lead, and toxic lead corrosion products. Collectors of glassware have to deal with some quite radioative uranium glass products.
As with our hobby, these risks are small, but collectors should be aware of them.
It's easy to learn how to manage the (small) risks in your collection, and to enjoy your minerals safely.
Jolyon
4th Jul 2013 15:38 UTCOwen Lewis
and
(5) Ignore them if they are either not moving or moving very slowly or far away.
N.B. It's not the looking that helps but sensible risk assessment.
Suggested 'rule of thumb' for risk avoidance in daily life:
- 50:50. Avoid - if there's any option.
- 1:10. Usually avoid - unless the reward is great. The chance of a failed marriage is around 1:3 with all the financial and emotional disaster entailed.
- 1:100 Life is full of them.
- 1:1000 and less. What risk?
Public advice is given to avoid where the assessed risk can be as low as 1:1,000.000.
4th Jul 2013 16:18 UTCcascaillou
This is why it was subsequently decided to lower exposure limits to 20mSv/year for professionals, and 1mSv/year on top of local background noize for the general public. Indeed, they're being extra careful on that last one, but that is motivated by the fact that they are not so sure about exposures under 0.1Sv.
4th Jul 2013 17:27 UTCAlfredo Petrov Manager
As for radon leakage from mineral specimens, I have not seen any studies on it, but there too I expect the risks have been greatly exaggerated. I saw one study on helium leakage from radioactive minerals and it was surprisingly low, especially from the solid primary minerals like uraninite. Most helium was retained inside the mineral - sometimes you can see it effervescing out if you dissolve a uraninite in acid. I expect the much larger radon atom would be even more thoroughly trapped inside the mineral than the much more mobile helium, but I'm not a physicist so I'll leave that speculation and research to others.
4th Jul 2013 18:15 UTCJan Hartmann
I once had a Uraninite I kept inside a sealed box. When I unboxed it for transport I took the specimen out of the box and measured the lower part of the box with my probe. I can't remember exact values but: I didn't see any particles in that box but it was still ticking well! I just had the specimen (a video here: UO2) in that box for a few months!
4th Jul 2013 20:21 UTCcascaillou
5th Jul 2013 01:50 UTCRolf Luetcke Expert
Every time I broke up those minerals I smelled like garlic for a couple of days, hand washing numerous times didn't take all the smell away.
I talked to people at the University of Arizona about it and they told me this wonderful story.
Back when the Getchell mine was in its early days, before they had everything electric, they used mules to haul everything. The mules lived underground where they hauled all the ore cars.
The mules drank the water that ran in the mine tunnels. None ever got sick. When the mine was electrified the owners thought they would do something nice for those hard working mules. They took the mules to a green valley near the mine and thought they would live the rest of their lives eating green grass in the open.
They checked on the mules and saw they were getting very sick and couldn't figure out what was going on. To treat them better then brought them back to the mine. As soon as the mules started drinking the mine water again they were back to normal. Seems the drinking of the arsenic laden waters had not been a problem but getting no arsenic in their systems was causing withdrawals and that was killing them. They lived out their lives at the mine, getting the arsenic they needed from the water.
Made my working with the arsenic ores much easier.
I agree with Alfredo about the mineral collector and taking normal precautions being sufficient.
Rolf Luetcke
5th Jul 2013 08:09 UTCJan Hartmann
The average lethal dose of As2O3 is 0,1 g. If you "eat" less and slowly increase the taken amount you can survive much more. Aristocrats did this some centuries ago to avoid getting poisoned by it.
6th Jul 2013 03:59 UTCRalph S Bottrill 🌟 Manager
So unless you stuff your pillow or mattress with radioactive samples, handling is not a problem. Dust may be a potential problem if you are grinding them up, but you would still need a lot in your lungs and crushing any rocks should be done with a dust mask. Radon may perhaps be an issue but we ensure good ventilation. So go play with your radioactive minerals as much as you like, just wash your hands!
6th Jul 2013 06:05 UTCFranz Bernhard Expert
- Jan: 1 kg Pitchblende gives ca. 2.5 mSv/hr (Milli!)
- Ralph: 0.05-0.5 kg Uraninite gives max. 1 uSv/hr (Micro!)
This is a factor of about 1000.
I have only a very simple and cheap geiger counter. It gives a background of about 0.2 MicroSv/hr.
A 40g-chunk of nearly pure uraninite from Joachimstal gives at direct contact about 50 MicroSv/hr.
Maybe the different counters recalculate counts to Sv in different ways?
Franz Bernhard
6th Jul 2013 06:46 UTCRalph S Bottrill 🌟 Manager
Amswering the second question first, for any accurracy you do have to get the detector calibrated for the radiation expected, as we did. Many detectors are much more sensitive to alpha than gamma radiation, but gamma is the biggest issue with most uranium ores.
Secondly, our samples were mostly not pure minerals, and also many were closer to 50g than 500g. Eg our 500g Cornish uraninite probably contained about 95% matrix, and this not only dilutes the radiation but absorbs most of it. It gave an overall average surface reading of 1uSv/hr, though it was a bit higher over some rich areas. So it's not a simple relation between size, grade and radiation dose, you would have to calculate the mas absorption coefficients of each element in the rock etc, so let's leave that to the physicists. I could well believe that a 1kg solid uraninite may be 1000X as radioactive as ours, and would be concerned about handling these for long amounts of time. But as Reiner said, how many hours a year would you hold a 1kg uraninite? The radiation from that would probably be easily detectable at normal viewing distances (~1m) but of negligible concern, unless again if eg you slept up against the.cabinet, or locked yourself in an airtight box with it. If you are concerned just stick to miniature and smaller specimens.
6th Jul 2013 09:23 UTCJan Hartmann
no offense but I think something was wrong with your measurements. I don't want to advertise my Youtube channel but just look at this:
Pitchblende
Background radiation is around 0,10 uSv/h. Just by the sound of my counter you should hear that this small Pitchblende with a weight of less than 100g is much more radioactive than 10x the background rad.!
Exact values are indeed hard to determine since most counters are calibrated on one nuclide. Mine was calibrated on Cs-137. Each and every nuclide releases different energies so you can't compare them pretty well in terms of doses like Sv/Gy etc.. Even small specimens should give high readings on a sensitive probe since at least 75% of the decays are Alpha+Beta.
6th Jul 2013 09:59 UTCFranz Bernhard Expert
Ok, only 5 % uraninite in a sample makes a big difference to pure uraninite. Much more then a factor of 20, considering increased distance for most part of the sample, (self-)absorbtion etc..
I can remember, me cheap radiation detector (only gamma, of course) is also calibrated with Cs-137. Ralph, to you know the difference of the calibration factors between Cs-137 and the uranium decay series? That would be VERY interesting! Thank you!
Franz Bernhard
6th Jul 2013 11:08 UTCJan Hartmann
- one of up to 0.512 MeV Beta- (Cs-137>Ba-137*)
- one of up to 1.174 MeV Beta- (Cs-137>Ba-137)
If 1) happens a Gamma decay of 0.6617 MeV to Ba-137 without * is going to follow.
When you take a look at the U-238 decay chain U-238 dc you see that some decay energies are lower, others are much higher. If my memory isn't failing the "worst" isotopes are Ra-226, Rn-222 and Po-218s. I can't tell you exact calibration factors though. The effective RBE factor (RBE for Alphas is 20 times the factor of Betas. That means if you have the above mentioned isotopes decaying in your body they are MUCH worse than a Cs-137 source from the outside.
Mind that 20 is also the factor of nuclear fission products! (Spaltprodukte Franz!!).
7th Jul 2013 00:37 UTCRalph S Bottrill 🌟 Manager
I relied on the Radiation physicists to help with the measurements and calculations as its incredibly complicated, and they seemed pretty happy with it all. I queried our calibration (I think it was Cs also) and indicated the likely chemistry of our samples, but they said it was OK
I cannot read the scale on your radiation monitor, but our monitors made a lot of noise and some went to the top of the scale too, but assuming they calibrated the monitors correctly the values were surprisingly low. We had to use the less-sensitive internal probe rather than the external one as that apparently cannot be calibrated accurately, not sure how it is with yours.
Still, 100g of pure uraninite is quite a lot, our richest sample probably had about 25g disseminated in the rock, so allowing for self-absorption you would expect to get a reading of perhaps 10-50x of our sample.
.
8th Jul 2013 03:54 UTCFranz Bernhard Expert
Still an interesting discrepancy! What do you think about a small, informal round robin test? I can mount a small piece, about 1 g, of uraninite in a plastic box and we can send it around and measure it with our devices? Who would like to participate?
Franz Bernhard
8th Jul 2013 12:57 UTCJan Hartmann
Ralph, I believe you when you speak about these low readings but let's go to that quote:
"<...> but our monitors made a lot of noise and some went to the top of the scale too, but assuming they calibrated the monitors correctly the values were surprisingly low."
If the background radiation is around 0,10 uSv/h at maybe 30 imp/min and you get 1 uSv/h while you can't count the impulses due to loud noise anymore; don't you think the scale is wrong? If it's a sensive probe (Pancakes with Alpha detection are indeed not suitable since to many Alpha impulses make dose measurements impossible) you should get extremely high readings much over 2 mSv/h. One guess: could it be that you are mistaking mSv and uSv? 1 mSv/h max. make perfectly sense with a sensitive probe. Another guess: could it be that you just measured one specific nuclide and filtered the rest of it? I easily reach 20 uSv/h with tiny MMs, but if you just have 25 g of Uranium spread over a 500 g ore 1 uSv/h it could be possible to get 1 uSv/h. That would not produce sounds like in my video though.
Concerning my SV-500 with B+G probe. The scale in the video is the third lowest and is used in ranges from 0 mrad/h to 500 mrad/h when the 0 - 50 mrad/h scale doesn't fit anymore. In the video it goes up to 50 mrad/h which is 500 uSv/h or 500 uGy/h. I compared a 40 g pure Uraninite piece from Jachymov on 5 different counters - 2x SV-500 with B+G probe, 2x cheap russians (ANRI, BELLA), 1x 2000€ Berthold lab counter. SV-500s and Bertholds values fitted within a +-30% range (Beta+Gamma) while ANRI and BELLA were about 60% lower. Since the last ones are thicker they might just be detecting Gamma rays.
8th Jul 2013 14:38 UTCOwen Lewis
-------------------------------------------------------
> ... They lived out their
> lives at the mine, getting the arsenic they needed
> from the water.
> Made my working with the arsenic ores much easier.
>
> I agree with Alfredo about the mineral collector
> and taking normal precautions being sufficient.
> Rolf Luetcke
Nice story Rolf. Yes, there is no doubt that many (all?) of us build a tolerance of many toxins through continual exposure.
Ethanol provides is an easy example. Life experience indicates that a 17 year old who drinks 70 cl of 40% ABV ethanol may die from the damage to liver function caused by that single act - if he does not die first from inhaling his own vomit whilst in a stupor. Ingesting about a half of that quantity of ethanol is likely both to induce vomiting and, the morning after, to leave him wondering if death might not habe been a preferable fate. OTOH, given a couple of decades of more or less daily ingestion of ethanol and consumption of a bottle a head of vodka at a sitting is simply considered to be no more that good party manners in some circles. Having chatted with a number of alcoholics either facing that last inevitable slide to a terminal loss of liver function - or who turned away from alcohol abuse at that very last point, a daily consumption of 2*70cl of 40% ABV seems, empirically, to be the tipping point to a certain (but slow) death.
Now, compare that with the UKG guideline of 'not more then 21 units a week' for an adult male. The 'unit' is a govt weasel-word for a quantity no one understands but, approximately, it is 70cl/60 of pure ethanol = 1.02cl. Thus (according to UKG's public health advisers) the *maximum* safe daily dose is advised as (21*1.02)/7 = 3.06 cl. The empirically determined killing dose (if maintained for more than a year or so) is (2*40*140)100 = 112.00 cl.
However, a health and safety permissive recommendation that is 3% of the dosage required for fatality is remarkably daring in comparison with some other govt advice of preventative measures. When, just a few years back, it was established that there was a risk of humans contracting 'variant mad cow disease (CJD)' from eating beef cut from near the bone, UKG banned the sale of beef 'on the bone' for over two years, until general appreciation of the sheer foolishness of the measure reached a point where the law and - hence the govt that enacted it - was the subject of wide-spread ridicule. At the time of repeal, it was admitted that the statistical risk of any beef related death from CJD had been calculated as >1:1,000,000 and not one single case of human infection had ever been identified. Yet the govt of the day found that to be sufficient cause (in maintenance of what it took to be good governance and the promotion of its own reputation) not just to issue cautionary guidance but to direct an outright ban, accompanied by the the needless destruction by burning of close to a million head of cattle.
8th Jul 2013 17:04 UTCEugene & Sharon Cisneros Expert
This should give a realistic idea of how hot small specimens can be. While I don't condone carrying these in your pockets, the radiation level from the whole lot is miniscule at a few feet.
Cheers,
Gene
8th Jul 2013 17:32 UTCSpencer Ivan Mather
Spencer.
8th Jul 2013 18:00 UTCJan Hartmann
I got a 210 g specimen from Jachymov with at least 2/3 of it being Uraninite and I got readings up to 700 uSv/h which would be around 70 mR/h - that would be easily within the range of your measurements.
Anyways, the question "why are small specimen sometimes nearly as active as bigger ones?" is pretty easy to answer. If you have bigger specimens with more Uranium in it most of the weak penetrating rays (A+B) get stuck within the sample. Since most of the measured dose consists of A+B the difference between small and big is not as huge as one probably would expect.
But: if you bring a metallic plate between probe and sample larger specimens are going to give much higher values because there are just much more penetrating Gamma rays while smaller specimens sometimes lose 80% of the dose without plate. If you have some different specimens available you can easily reproduce that.
Minerals with tiny needles (for example Cuprosklodowskite) tend to give insane doses compared to their size. That's just because needles don't absorb many of the A+B particles.
8th Jul 2013 19:09 UTCJohn Sobolewski Expert
Plain stupidity is he reason they ran out of the building. Too many people today are not taught to use common sense. Any mention of radioactivity, asbestos or something similar and they panic. Of course, they have no problems with flying because they are not aware of the (slight) exposure to cosmic ray radiation or of exposure to fiber glass used for insulation simply because it is not called asbestos, even though some studies have shown it to be as dangerous as asbestos. In fact studies show that any stiff fibers in the air with an aspect ratio of 30 or more are dangerous. John S.
9th Jul 2013 01:00 UTCEugene & Sharon Cisneros Expert
I purposely didn’t mention conversions from mR to uSv for two reasons.
1. Having used mR on my job for 38 years, as a DOE radiation worker, I’m afraid that I am stuck in my ways.
2. I thought that it would make a bit more work/fun for my European friends.:-D
I was prompted by this discussion to make a simple experiment. I haven’t come to any conclusions other than the amount of measured beta emission compared to gamma emission is small for both Uraninite and Cuprosklodowskite. Low tube efficiency for beta probably makes this exercise somewhat inaccurate, but just for fun...
I mounted the TBM-3S about 2” above each small (~1”X2”) specimen and took readings without and with 4 layers of Aluminum foil between the specimen and the counter There was no difference between readings with 1,2,3 or 4 layers of foil indicating how energetic gammas are.
Uraninite
No foil 35000 CPM
Foil 33000 CPM
Ratio ~0.986
Cuprosklodoskite
No foil 37000 CPM
Foil 34000 CPM
Ratio ~0.907
Gene
9th Jul 2013 06:33 UTCFranz Bernhard Expert
3.6 MicroSv/h and 122 cpm (including background).
So this device is VERY insensitive (probably very small counting tube?)
Background is about
0.2 MicroSv/h and 6 cpm.
Jan, please could you pm me your mailing adress?
Gene, are you also interested to measure this sample? Anybody else?
Franz Bernhard
9th Jul 2013 06:51 UTCJan Hartmann
Until then I have to share another video of a miniature I measured: Curite
Without shield this specimen goes up to 250 uSv/h (second scale) with B+G while it just reaches 50 uSv/h (first scale) with shield. That's -75%.
Jan
26th Jul 2013 14:50 UTCcascaillou
a collection of uranium ores roughly equal to 1kg of uranium metal was measured at different distances (with 0.1µSv/h as the background noize and detection limit):
at less than 1cm: 350µSv/h
at 10cm: 70
at 20cm: 28
at 30cm: 15
at 40cm: 9.5
at 50cm: 8
at 60cm: 5
at 80cm: 3.8
at 1m: 3 (let's note that this value is coherent with the radioactivity of 1kg uranium metal at 1m which is indeed known to be 3µSv/h)
at 1.2m: 1.7
at 1.5m: 1.4
at 2m: 1.2
at 2.5m: 0.6
at 3m: 0.4
Unfortunately, the distance at which the values drops to 0.1µSv/h was not mentioned.
Similarly, here are the measurements from a collection of uranium ores/minerals roughly equal to 500g of uranium metal (with 0.1µSv/h as the background noize and detection limit):
at less than 1cm: 150µSv/h
at 10cm: 25
at 20cm: 10
at 30cm: 8
at 40cm: 4.5
at 50cm: 4
at 60cm: 3.5
at 80cm: 2
at 1m: 1.5 (here you can see that the radioactivity decreases proportionally with the quantity of uranium)
at 1.2m: 1.2
at 1.5m: 0.7
at 2m: 0.5
at 2.5m: 0.4
at 3m: 0.2
Unfortunately, the distance at which the values drops to 0.1µSv/h was not mentioned.
Please note that you don't need that many samples to reach the equivalent of 500g uranium!
Anyway, it would be wise to make your own measurements for your collection, and do the math: evaluate how much time a day you would spend at let's say 50cm, 1m, 2m, 3m and 4m from the collection, then add up the doses and multiply by 365 days, convert to mSv and substract your local annual background noize. Then just confront the result to recommended exposure limits.
You can easily see why you shouldn't store radioactive minerals in a room where you spend much of your time.
27th Jul 2013 18:23 UTCEugene & Sharon Cisneros Expert
Thanks for posting the radiation measurements from the French journal, which I find to be interesting, but not worrisome. While Uraninite contains 50%-85% Uranium, most radioactive minerals contain less. For example, Carnotite, Autinite, Uranophane, torernite, etc. contain 45%-60% and Davidite, Samarskite contain only 1% to 8%. It would be reasonable to assume that a radioactive mineral collection would be comprised of these and other radioactive minerals, so I could guess that the total weight would be several kg; a large collection indeed! For most collectors, a collection containing 1kg of Uranium, in ore, would be quite ambitious and I would guess most would be smaller.
Assuming the above mentioned collection, I’m not sure that I understand your logic of “You can easily see why you shouldn’t store radioactive minerals in a room where you spend much time”. As you suggest, let’s do the math.
The radioactivity, for one of the collections, was measured to be 0.4uSv/hr at 3m. So, 0.4uSv/hr X 8760hr/yr = 3.5mSv/yr = 350mrem/yr. That is about one half of the average exposure rate 6.2mSv (620mrem) in the U.S. due to the sum of natural and manmade sources. And, that would assume that you spent 24hrs/day for a year at a distance of 3m from the collection. Not too likely…
To put that into perspective, a study showed that commercial airline pilots receive dose rates of 2mSv – 6mSv per year (200mrem – 600mrem). The study involved ~10,000 pilots and was tracked over a period of 17 years. The analysis of years of flight and types of cancer is statistically complicated, but the bottom line is fairly simple. During the follow up, 466 cases of cancer were diagnosed as compared to 456 cases predicted from general population statistics. Yes, there was an increase, but consider the following. The pilots with the highest incidence of cancer had careers of over 20 years. There is also the question of how much the electromagnetic emissions from electronic equipment contributed. So, using these findings, we could extrapolate that if we remained at 3m from the collection for 20 years continuous, an unlikely scenario, we may be subject to an increased risk for cancer by a factor of 466/456 = 1.02.
The U.S. Nuclear Regulatory Commission limits radiation exposure to the public to 1mSv/yr (100mrem/yr). However, that is very conservative as they limit the exposure for radiation workers to 50mSv/yr (5000mrem). In that context, the yearly exposure to your afore mentioned collection is only ~7% of that. The NRC also states that “although radiation may cause cancers at high doses and high dose rates, currently there are no data to establish unequivocally the occurrence of cancer following exposure to low doses and dose rates – below about 100 mSv (10,000 mrem)”.
In my opinion, the risk from exposure to a collection such as you mention is very small, though it would always be prudent to limit exposure to what the radiation community refers to as ALARA (As Low As Reasonably Achievable). The NRC states the following: “Even so, the radiation protection community conservatively assumes that any amount of radiation may pose some risk for causing cancer and hereditary effect, and that the risk is higher for higher radiation exposures. A linear, no-threshold (LNT) dose response relationship is used to describe the relationship between radiation dose and the occurrence of cancer. This dose-response hypothesis suggests that any increase in dose, no matter how small, results in an incremental increase in risk. The LNT hypothesis is accepted by the NRC as a conservative model for determining radiation dose standards, recognizing that the model may over estimate radiation risk.”
A far greater concern, than exposure from fixed sources, with such a collection would be airborne particles (non-fixed radiological emitters). Loose particles, such as dust, are of concern because they may be ingested or inhaled. Inhaled particles remain in the lungs for long periods of time and continuously irradiate cells. So, while the radiation from fixed radiological sources is easy to mitigate by time, distance and shielding, non-fixed radiological sources are far greater concern. It is very important to avoid any activity that may produce small particles or dust and to keep specimens in some sort of container that will catch shed particles. It would be prudent to wash one’s hands with soap and water after handling a radioactive specimen. Visible particles that may fall off of a specimen should be picked up with scotch tape and disposed of.
IMO, the curating of a radioactive mineral collection need not be a dangerous or hazardous activity if one understands the principals of radiation safety and follows radiation safety procedures.
An excellent source of information relating to radiation safety is the Health Physics Society.
Gene
27th Jul 2013 18:34 UTCRob Woodside 🌟 Manager
There is also the question of how much the electromagnetic emissions from electronic equipment contributed.
A good post but how much ionizing radiation do you expect from "electronic equipment"?
27th Jul 2013 18:59 UTCcascaillou
Just a few additional notes:
In france radiation exposure limits for people working with ionizing radiation is 20mSv/year, and for the general public it is 1mSv/year on top of local background noize (let's note that in france, average national background noize is around 1mSv/year)
Concerning the quantity of uranium in uranium ores, let's keep in mind that a massive torbernite or autunite (50%U content) that is 7x7x6.5cm in size is already about 500g uranium.
27th Jul 2013 19:15 UTCJan Hartmann
27th Jul 2013 19:28 UTCRob Woodside 🌟 Manager
28th Jul 2013 02:50 UTCEugene & Sharon Cisneros Expert
Good catch! Electromagnetic radiation (EMF) is not ionizing radiation, so if there is any causality regarding cancer it is by another mechanism. That's why in my post, it is a question. Some credible studies have been done here and abroad with varying conclusions. Some studies show a causality and some do not. In the studies that do show causality, the effect is very small. So again, as I said it is a question that was asked in the airline pilot studies.
There are no government regulations that I know of regarding EMF at present. I worked at the SLAC National Accelerator Lab for 38 years around fields that were many orders of magnitude greater than any pilot would ever be exposed to and I'm still around. However, that may account for my occasional wacky post. :-D
Cheers,
Gene
29th Jul 2013 15:03 UTCRoger Curry
There is a mineral which would likely be lethal if inhaled or ingested on a microgram scale - radium sulphate radiocolloid aggregates formed within the last 15,000 years.
Once a deposit of pitchblende has been established, it takes around half a million years for the deposit as a whole to achieve it's maximum radioactivity. This is because of the formation of radium and other radionuclides has to reach equilibrium. The uranium dioxide is insoluble until further oxidation, but the radium can be leached out at extremely weak concentrations by water. There it forms radiocolloids, which can aggregate to produce deposits of pure radium sulphate. Since the half life of radium is only 1620 years, these remain highly dangerous for only a few thousand years.
So if a mine enters an area where this mineralisation is still taking place, or has "recently" stopped, miners or mineral collectors could be exposed to tiny particulate killers.
An interesting paper on radiocolloids by Yagoda can be found here.
Regards,
Rog.
29th Jul 2013 16:52 UTCJoshua Young
29th Jul 2013 18:41 UTCEugene & Sharon Cisneros Expert
You are correct in assuming that a dosimeter only captures a small area of the total radiation impinging upon the body. Dosimeters are worn on the torso of the body to monitor exposure to most of the vital organs. It is assumed that if you are not very close to the source the field is uniform across the torso and that the radiation measured by the dosimeter also applies to the larger area. Where workers may be close to the radiation source and are working with their hands, ring dosimeters are often used as well.
Gene
29th Jul 2013 19:23 UTCcascaillou
By the way, while many mineral collectors are involved into thematic collections, I guess that the pharmacological theme has never been exploited despite it would be a very interesting guiding principle for a collection.
29th Jul 2013 20:53 UTCSpencer Ivan Mather
Spencer.
29th Jul 2013 23:24 UTCRob Woodside 🌟 Manager
Oddly chemical toxins will last forever, if they are not chemically altered. However radioactives, that strike fear into the general population, cannot be chemically altered, but just decay away.
30th Jul 2013 16:23 UTCcascaillou
HAHAHAHA
31st Jul 2013 04:13 UTCRob Woodside 🌟 Manager
31st Jul 2013 17:29 UTCReiner Mielke Expert
31st Jul 2013 19:21 UTCEugene & Sharon Cisneros Expert
Regarding exothermic reactions, while you are quite correct in one definition of burning, it is also defined as "to cause to undergo nuclear fission or fusion". Here is an example quote from untied-nuclear.org .
"High-level waste (HLW) arises from the 'burning' of uranium fuel in a nuclear reactor. HLW contains the fission products and transuranic elements generated in the reactor core. It is highly radioactive and hot, so requires cooling and shielding. It can be considered as the 'ash' from 'burning' uranium."
Gene
1st Aug 2013 01:58 UTCDoug Daniels
So, does this mean the mods may have to add a new entry to each mineral -"Medicinal benefits"?
1st Aug 2013 13:33 UTCcascaillou
24th Aug 2013 08:53 UTCRalph S Bottrill 🌟 Manager
24th Aug 2013 13:00 UTCOwen Lewis
Sadly, with the advent of a later blessing to humanity, the 'Drugs War', K Morph simply disappeared from the dispensaries. This was a sad loss to those of us who had discovered that, if a 200 ml bottle of the stuff was left to sit undisturbed for a few days, the kaolin would entirely come out of suspension and the pure tincture of morphine could be carefully decanted off. Drunk in this way, one could enjoy a relaxing, happy-hour with a friend without suffering the side effect a near-terminal case of constipation in consequence.
1st Sep 2013 19:05 UTCcascaillou
4th Mar 2014 11:26 UTCcascaillou
10th Mar 2014 00:51 UTCcascaillou
13th Mar 2014 01:37 UTCRock Currier Expert
13th Mar 2014 03:10 UTCD Mike Reinke
My question is, does anyone bottle that water, for sale? Drink some, and put a beaker full in your mineral collection today. Happy collecting.
13th Mar 2014 10:13 UTCcascaillou
However, zabuyelite is lithium carbonate which is precisely the compound that is used in psychiatry but as a mineral it is very rare and microscopic, and the lithium content of nalipoite is a bit low, so we're left with lithiophosphate (it's kind of a rare mineral but it has decent solubility, decent lithium content, no associated toxic elements, and can reach 5cm in size, typically as cleavages)
On the other hand, there's no directly bioavailable lithium mineral occuring in industrial quantities that I'm aware of, thus lithium is extracted from other lithium ores or concentrated from lithium rich waters.
But I insist, lithium is dangerous, and one should definately not self-medicate with lithium.
13th Mar 2014 14:02 UTCRolf Luetcke Expert
Not long ago a child in a Tucson school had dropped an old mercury thermometer and the school was evacuated and a whole team came in with haz-mat gear on to remove the mercury. I think it was a "bit" excessive!! We are both in our mid 60's and seem not to have any adverse effects from our playing with the mercury as kids.
Loved all the comments with this thread and followed it with interest and agree with Alfredo on his comments.
I used to work with ores of Arsenic when making mineral collections and was a bit worried about smelling like garlic for hours after breaking up the orpiment and realgar but after I found out the facts was not so worried.
Rolf
13th Mar 2014 17:36 UTCcascaillou
13th Mar 2014 20:50 UTCRock Currier Expert
So a kid is expelled from school for bringing a knife to school. The knife was a tiny blunt plastic thing included in a prepackaged crackers and cheese spread kit that his mother had put in his lunch bag. The matter was not resolved till an irate parent took a sharp "lead" pencil off the principals desk and telling him that she could probably kill him with it but that not with the knife in the crackers and cheese lunch item. Plans are developed to build strong high chain link fences around parts of a counties where wind blow asbestos fibers around naturally. This has happened perhaps has been happening during recent geological time and no one living in the area has seemed to have suffered ill effects. Someone finally looks at the money involved and said is this really a problem we need to solve?
So: How important and necessary are health warnings for mineral specimens? Often people do not make the distinction between the large quantities of a mineral and long term exposure to them and mineral specimens. Do we want to be responsible for creating a haz mat squad call out because someone brings a specimen of orpiment or autunite into a class room and drops it on the floor? No one has ever been made ill or their health degraded by their mineral collection(s). Vastly more harm has resulted by accidents driving around in pursuit of our hobby and by collecting accidents than the minerals themselves.
Any health warnings that we put of our mineral species pages should probably be headed with "Handling specimens of this minerals will not harm you or be a hazard to your health any more than handling food in you kitchen, going to the bathroom, working in the garden or on your car. General sanitation rules apply. Wash your hands when you are finished with any of these activities." For a few minerals like some asbestos group minerals, radioactive minerals, some arsenic and mercury minerals we may want to include some additional text about how contact with quantities of these minerals or dust from them might in the long term be dangerous to health and site examples. If the Merk Index lists an LD 50 for the mineral, then of course we should list that. If there are not know examples of how exposure to this mineral has harmed people then that should also be stated. We must try and put things in perspective and in a way that people can read about them and get scared and call out the haz mat squad.
13th Mar 2014 21:58 UTCcascaillou
For instance, from reading the values, we can't see that calomel shows some toxicity, but the important thing is to note that it is 11x less toxic than montroydite, so we can reasonably decide that the moderate toxicity of calomel isn't worth mentioning in the mindat mineral pages (I can't see anyway for a collector to accidentally ingest a toxic quantity of this mineral!)
That's precisely what the lawyers and insurance companies are not allowing themselves to: some perspective.
ps: I named this topic 'health warning' because that's how mindat puts it in mineral pages, but I realize that might sound like terrorism, so I changed the title so to make it clear that this topic is nothing but a study about minerals under a pharmacological perspective. I also edited my original post to make it clear that "this topic is not intended to be alarmist, simply I think that the biological effects of minerals (toxicity, medicinal, nutritive...) is an interesting topic to discuss: when mineralogy meets biology". That's probably better that way.
13th Mar 2014 22:59 UTCRolf Luetcke Expert
Last example was a teacher that came into my old store and said she loved the way the mineral Chrysotile looked in its natural state and she wanted to take some of the "asbestos" in its natural state into the classroom to use as a teaching tool but the school regulations forbade bringing many things into a classroom and asbestos was on the list. (don't think thermometers were on the list)
I told her to use the mineral name and nobody would be the wiser as long as she stressed the mineral is not particularly dangerous in its natural state but rubbing the fibers loose is what causes problems. She was aware of this and I said that it may be a way around the "list" problem to use the chrysotile name.
Yes, there are a number of toxic minerals and common sense needs to be used when working with any of them.
One story I remember well from Bisbee was a miner bringing home a great Chalcanthite stalactite he had found in the mine and set it on the living room table. Their little child came in the room when the parents had left and found the pretty colored object and I am sure you know where this story went. Sorry to say a tragedy happened here but the miner didn't know of the toxic nature of the Chalcanthite. It may be well known to adults but to a child it was something to put into its mouth.
It is good to familiarize oneself with the potential dangers but we need to do it as individuals and not with regulation.
Rolf
14th Mar 2014 10:21 UTCcascaillou
However I don't see the point in mentioning toxicity of minerals between 100 and 300mg/kg, unless water soluble (but that's just being extra-cautious, thinking of the kids that can be hungry enough to eat such a quantity of the fool tasting chalcanthite to end up in the hospital...)
15th Mar 2014 08:18 UTCRock Currier Expert
15th Mar 2014 15:30 UTCcascaillou
Yeah, that was precisely my point, the kid would have to be very very hungry (to get real sick, one would need to ingest a substantial amount of this fool tasting mineral, which I think is unlikely to happen)
Actually, a 5mm sized cube of montroydite would be enough to kill you, and you could get real sick from less than that.
Which was also my point: we can't consider every toxic minerals on the same scale, some are a world apart in term of toxicity.
For instance the ld50 in rat of montroydite is about 16 times lesser than for chalcanthite (please note that in phamacology, a 2x increase in dosage can already be significant, so a 16x factor is a really huge difference! Just think about the difference between 1 aspirin tab and 16 aspirin tabs...)
16th Mar 2014 16:09 UTCAdam Kelly
If we are going to label these minerals as toxic, we should include "Happy Meals" on the danger list.
For that matter, you could die from drinking too much water.
I think there are far more dangerous things used in most of our daily lives.
Just my two cents, but be careful you don't get copper toxicity.
16th Mar 2014 20:37 UTCcascaillou
16th Mar 2014 21:18 UTCAlfredo Petrov Manager
Probably true for the vast majority of mineral collections too. :-)
16th Mar 2014 21:45 UTCPeter Haas
-------------------------------------------------------
> <...> in weekly acidic conditions like our stomach <...>
pH in the human stomach is around 0-1. This is a strongly acidic medium.
16th Mar 2014 22:49 UTCcascaillou
that's also my opinion, but I think that when something is significantly toxic, the information should simply be made accessible to the people interested in it.
Considering that each Mindat mineral page does already feature a "health warning" column, I don't understand why one would want it to be left blank when there is some available data to be filled in.
Also, I don't look at toxicity data only in a safety perspective: I also consider it as a scientifically interesting property that is inherent to a given mineral.
16th Mar 2014 23:14 UTCAlfredo Petrov Manager
16th Mar 2014 23:19 UTCcascaillou
As a rock nerd, I admit that I'd love to build a small pharmacological themed collection, but it's hard to get your hands on such minerals in an attractive form (most specimens I've found for sale were either microscopic crystals or shapeless veins in matrix)
17th Mar 2014 13:49 UTCSophiaJoy MB
Could normal tumbled stones have toxic minerals in them??
17th Mar 2014 15:07 UTCAlfredo Petrov Manager
A completely different topic is the dangers faced by the lapidary workers who actually manufacture your tumbled stones... Lots of sludge which would turn into fine dust if it dried out. And fine dusts (of all kinds, not just minerals), can indeed have deleterious effects on the human body. I'm quite terrified of vacuum cleaner dust myself. I consider vacuum cleaner dust an excellent reason to have moppable floors and not carpets or tatami. But that should be more a topic for the lapidary messageboard on Mindat, or Gemdat, and is of little concern to mineral collectors.
17th Mar 2014 15:29 UTCcascaillou
17th Mar 2014 23:37 UTCSophiaJoy MB
Regarding Uranium, it is dangerous even if I don't touch it, right? Still, is it safe (enough) to keep unidentified minerals that could have uranium in them if I don't eat/crush them?? Is that what you mean?
18th Mar 2014 00:08 UTCcascaillou
Being unknowingly supplied with a significant quantity of radioactive rocks sounds unlikely, though. But why not just get your rocks identified...that would make more sense that applying safety measures against harmless pieces of rock.
8th May 2014 13:20 UTCcascaillou
8th May 2014 13:25 UTCRock Currier Expert
8th May 2014 13:33 UTCcascaillou
I was actually very reluctant to formulate any precautions for minerals such as orpiment, chalcanthite and especially cinnabar which are not much of a concern, but I still choosed to include these only because they are commonly encountered by beginners who often ask about their toxicity (precisely to show that unless eating or breathing these, they would be prefectly safe).
note: despite there have been a few cases of kid poisoning themselves with chalcanthite specimens, this is less likely to happen than kids poisoning themselves with household chemicals or pharmaceuticals, and let's also add that those synthetic chalcanthite crystals are much less toxic than those synthetic lopezite crystals.
PS: as I had discussed earlier, I might have missed a few significantly toxic minerals that might also deserve a warning (maybe amongst arsenites and arsenates, tellurites and tellurates) due to lack of any toxicological data available. However I thought it would be wiser not to make any warning for these without any solid proof of toxicity (as we want to avoid uselessly worrying people).
8th May 2014 16:56 UTCAlfredo Petrov Manager
8th May 2014 17:14 UTCReiner Mielke Expert
8th May 2014 17:41 UTCcascaillou
However, there would be exceptions:
-uranium and thorium are always radioactive (no matter the form). Thus, for those, let's put it as "Contains significant quantity of uranium and/or thorium"
-cinnabar is insoluble and has very low bioavailablility (so that only chronic inhalation might be a cause of concern). Then, let's just make an exception for that mineral by not mentioning the element at all.
Does that sound about right?
8th May 2014 17:53 UTCAlfredo Petrov Manager
8th May 2014 18:09 UTCcascaillou
Reiner Mielke, when you look at the label or msds of a chemical compound, you will immediately come through classification through hazard codes and hazard pictograms. Those codes and pictograms are already taking into consideration what the toxic doses are, for instance, skull&crossbones means 'toxic' or 'highly toxic', which basically means that the toxic dose is quite small. The classification has already been established by toxicologists for you, precisely so that when you want to know how "bad" a chemical is, you won't need to look into all the toxicological data they used to build their classification (and anyway such detailed data would be counterproductive by making the average user confused).
I kept this idea in mind when building my list of safety precautions.
8th May 2014 18:34 UTCAlfredo Petrov Manager
For some of those species (downeyite, for example), we could add the sentence: "Total quantity of this species available in all mineral collections on the planet combined does not add up to one lethal dose."
Putting things into perspective is important, or else the scientifically illiterate (who seem to be the majority of the population these days, plus a big fraction of government bureaucrats) go into panic mode unnecessarily.
8th May 2014 18:49 UTCcascaillou
For instance, Rock Currier was under the impression that no one had ever been hurted by mineral specimens, but I know of at least two cases of poisoning from chalcanthite samples (two cases which might as well have been left unreported, or which could have been reported without me ever hearing of it)
As to the minerals I mentioned to be toxic or highly toxic, most are indeed very rare and beginers will probably never hear of these, thus there shouldn't be any panic.
8th May 2014 19:16 UTCAlfredo Petrov Manager
8th May 2014 19:39 UTCDoug Daniels
8th May 2014 19:59 UTCeugene reynolds
8th May 2014 20:56 UTCRoger Lang Manager
Cheers
Roger
8th May 2014 23:20 UTCcascaillou
but beware that 0 proof alcohol is dangerous, it has been reported to cause rust
1st Jun 2014 20:23 UTCcascaillou
2nd Jun 2014 03:00 UTCMark Heintzelman 🌟 Expert
I like the list thus far, and thank you for this effort, much appreciated. I would also like to see Brucite var. nemalite included on the asbestos mineral list. The fibrous form of brucite has a particularly high Fe2+ component, so it had been evaluated for it's capacity to induce lipid peroxidation and to activate intra-cellular anti-oxidant enzymes. The results of the study at the Laboratoire de Cytophysiologie et Toxicologie Cellulaire, Universitë de Paris, France, showed that nemalite has a strong oxidizing power as well, inducing an oxidative stress on airway epithelial cells. It is one of the nastier asbestiform minerals and definitely ought to be included.
MRH
2nd Jun 2014 14:54 UTCcascaillou
ps: for the record, lately a collector reported a possible case of cobaltomenite poisoning (with severe gastrointestinal disorders), but confirmation is needed (ie. was the mineral correctly identified? was the illness actually related to selenium poisoning?)
2nd Jun 2014 16:08 UTCMark Heintzelman 🌟 Expert
Here is a link to the publication in pdf form: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1519846/pdf/envhper00375-0078.pdf
This compatative study also covers Chrysotile (Fe2+) and Hematite (Fe3+). Fe3+ seems to have no ill effect.
MRH
2nd Jun 2014 17:50 UTCcascaillou
Let's note that asides from the currently regulated asbestos minerals (Chrysotile, Anthophyllite, Tremolite, Actinolite, Amosite, and Crocidolite), there are indeed a few other minerals which are known or suspected to cause mesothelioma from prolonged exposure to fibers via inhalation:
-Winchite
-Richterite
-Magnesio-riebeckite
-Antigorite
-Erionite
-Nemalite
-Palygorskite-Sepiolite
I know that erionite is a very nasty one. But for the others, I just don't know how bad they are, comparatively to the regulated asbestos minerals.
2nd Jun 2014 23:33 UTCRalph S Bottrill 🌟 Manager
3rd Jun 2014 02:11 UTCcascaillou
One other thing I'd like to discuss is radian barite. Webmineral gives an estimation of its radioactivity at 44452.81 mRem/h for a 100g sample if hold in the hand for one hour. I don't know how they got the value (unfortunately I didn't find any contact email to ask?), but if that's correct, this sounds like extremely radioactive! (for comparison a 100g uraninite is estimated at 197.60mRem/h). So, I was thinking that maybe my formulation of safety precautions for this mineral (see page 6 of this topic) might not be severe enough: does that mRem/h value sound coherent? then should we mention that such mineral should be stored inside a lead box? that anti-radiation gloves are recommened for manipulation? that surfaces must be cleaned-up after manipulation? Or would that be excessive?
Indeed, I have limited knowledge of radiotoxicity, so maybe someone more knowledgeable than me might chime in.
3rd Jun 2014 02:44 UTCDoug Daniels
3rd Jun 2014 03:00 UTCcascaillou
3rd Jun 2014 04:22 UTCAlfredo Petrov Manager
For the same reason, brazil nuts are among the most radioactive foods - The nut concentrates Ba from the Amazonian soils and any tiny traces of Ra get concentrated along with the Ba.
It would be interesting to check other recently growing primary Ba minerals for radioactivity - harmotome from geothermal wells, anyone?
3rd Jun 2014 13:46 UTCNelse Miller
3rd Jun 2014 15:53 UTCcascaillou
Note that all barite is similarly radioactive when first deposited
I don't understand. I mean wouldn't it depend on how much Ra is available in the envrionnement to be drained by the growth fluid? Shouldn't we expect the initial radium impurity content of a barite to be much higher if the barite is growing in an uranium rich field. No?
3rd Jun 2014 16:02 UTCAlfredo Petrov Manager
I'm sure you're right that barite forming in a uranium deposit would be more highly radioactive, but I'm just not aware of any barites currently growing in uranium deposits. Remember that the most necessary criterion is that they must be very young - a few decades old at most - which is almost no age at all on the geologic timescale. I tested a radian barite ("hokutolite") from an old collection, maybe 90 or 100 years old, and the radioactivity was negligible.
3rd Jun 2014 19:18 UTCcascaillou
see discussion here: http://theodoregray.com/periodictable/Elements/094/index.html
3rd Jun 2014 19:28 UTCReiner Mielke Expert
3rd Jun 2014 19:34 UTCcascaillou
3rd Jun 2014 23:00 UTCRob Woodside 🌟 Manager
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Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 19, 2024 03:19:56