Note to ebay: This is not a hazardous material. These are pebbles, small rocks, not unlike those pesky ones that get stuck in your shoe and bug you for like five hours until you finally give in and go through the ordeal of removing it. This item is shipped in compliance with USPS Publication 52, and is a natural mineral specimen, as it is clearly defined in 49 CFR. This mineral is usually dull and lacks brightness under long wave UV light. The pictures look exactly how it looks in person, and that's just with a little UV LED flashlight. All uranium ores have their quirks, sometimes you get a very rich batch of pitchblende with radium levels which make in notable, it's the same deal with Autunite. This is without a doubt the highest count rate I have seen on a uranium mineral, period. Crystals were tweezed by hand. It's kind of neat to have a specimen which manipulates the way the GM quenching mechanism works in order to produce extremely high counts. This was a discovery; swept up the bits and pieces which have fallen off over the years from my attic display, and my jaw dropped. Using a calibrated adsorber set, the majority of emission is low energy beta. So, while there is no health physics dose rate conversion, the gamma is so low in comparison to alpha and beta, that inhalation and hand washing precautions are all that's needed. Surface dose rate outside the glass vial is just over 26mR/hour, and it's undetectable at six feet on both low energy gamma and 44-10 2 inch scintillators. This is exceptionally strong in regard to low energy beta particles. Pancake probes and all thin window mica probes over-respond to low energy beta, so the actual DOSE RATE is very low, whereas the COUNT RATE is extremely high. It counts at about 51,000 CPM on a 44-9 probe from inside the bottle. The gamma rate is about a tenth of what my highest quality pitchblende samples emit. It doesn't contain the high radium level which pitchblende does. It pegs every 500,000 count meter I have, drives the ion chamber wild, and maxes out 5,000,000 count meters using a G5 FIDLER probe It's alpha/beta hot. Pictures are from the same batch but from a different bottle. Autunite is very difficult to handle in its natural state. Museum samples of Autunite MUST be lacquered (I use MineraLac neutral photo density neutral semi-gloss) to prevent it from crumbling. This piece has NO LACQUER or polish, as lacquer blocks alpha particles almost completely. It's better to just contain it and let it crumble naturally. The alpha and low energy beta rate will only increase. This is a naturally occurring radioactive mineral and is legal to own, so long as there is no modification or chemical extraction of any material. This Autunite is several times hotter than other minerals because the density is very low, and the crystals are very small. Alpha particles can make it through the thinnest layers of this rock (just like they can get through the mica on a pancake probe), and beta particles of all energies go through it as well. It does not have the self-shielding properties like pitchblende, which blocks the vast majority of its own radiation. I measured this with three different identical probes and two digital counters, plus a few analog counters. It didn't push the probe in to continuous discharge or saturate it. In 15 years of routine pancake probe use, I haven't ever tried used mica probes for anything above 500,000 CPM, as the probe will go in to continuous discharge. so it's exciting to know that it can actually hit 800K while still detecting every particle and recover so quickly without continuous discharge... The following counters and probes were used to verify this, all were set to correct dead time. NONE of the probes went in to continuous discharge, presumably because the low energy beta is more easily quenched by the halogen gas in the probes. -Eberline ASP-1 with a Bicron PGM probe. -The pictured Eberline/Thermo E-600 with 3 different identical SHP-360 (identical to 44-9) probes. -An eberline ESP-2, with a second PGM probe (identical to 44-9) -Ludlum models 3 and 15 with actual 44-9 probe. Regarding fluorescence: The intense fluorescence in the photos is long wave UV light at about 330-380nm held at a few inches. The picture which looks like a piece of glowing Fukushima fuel was taken before the ipad lens aperture closed up, and its included just because it's awesome and is what it actually looks like. I plucked the brightest crystals with tweezers. This is a combination from many samples, and is intended to be the hottest natural source available, anywhere, period. I recommend the inova 5 LED UV light for viewing the fluorescence. It's spectacular. Autunite fluoresce best at about 350-380nm, and the inova put out just about that. Please contact me after doing your measurements. I would love to hear about the counts you're getting with different probes and meters with older or different circuitry. Make offers or message me with questions.
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