[Rockhounds] UV Light recommendations wanted

Wed Jul 11 21:54:57 PDT 2018

John,

Given what Pete said, I took out more Hyalite and measured it. I have one from Zacatecas, Mexico, that fluoresces brightly under every form of UV I own, including the Philips Black Light Bulb. It is more than 30 times background radiation for a small specimen (greater than 3 microseiverts/hour, where background for me is usually 0.08 uS/hr). It does say there are autunite inclusions, which would explain a lot of radiation, but if your rocks are from Zacatecas or glow brightly, I would assume they contain more than a negligible amount of uranium. 

On the other hand, I have a specimen labelled Hyalite with quartz flower in Rhyolite from the Candelaria Mine in Sonora, Mexico. This is a pretty piece where most of the weight is clearly in the matrix. It glows a nice green under short wave, but it doesn’t do that much with my high power long wave light and glows a pale white with the black light bulb. It is radioactive, but it is barely 2x background, and my background is probably a lot lower than yours. I also checked out a piece from Namibia. It glows brilliantly under SW, but less so under LW and poorly under the black light bulb. It is barely 3x background. 

So in summary, if your stuff glows bright green under even bad UV lights, assume it is reasonably radioactive. If it doesn’t glow well or at all with a black light bulb, it probably isn’t radioactive enough to worry. 

The moral of the story? Find a friend with a geiger counter and a bunch of different UV lights and you wont have to guess ;-)

Doug

> On Jul 11, 2018, at 5:52 PM, pmodreski at aol.com wrote:
> 
> Hi John, I was going to respond to you too, but you've received "lots" of replies from a number of people, so you've probably got all the info you need.
> 
> But what I'd say, is that, I think the uranium-rich hyalite from Spruce Pine is quite the exception as to its uranium content, and most other hyalite, especially as commonly seen as very thin (pretty much invisible?) coatings on chalcedony as you say, is probably going to contain a negligible amount of uranium, and the radioactivity is, in most cases, not even measurable above background with most radiation instruments.
> 
> And as to a UV light; you'll want a short-wave UV light for sure, and basically any SW light will work just fine.  If you think you'll be using it "in the field" searching for fluorescent minerals, get a portable one; otherwise, just one that uses an electrical outlet is fine.  For most purposes, I'd just get the plug-in kind; no batteries to mess with.
> 
> Those are my simple answers!
> Cheers, Pete
> 
> 
> 
> -----Original Message-----
> From: John Scully <jscully216 at gmail.com>
> To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors <rockhounds at rockhounds.drizzle.com>
> Sent: Wed, Jul 11, 2018 4:44 pm
> Subject: Re: [Rockhounds] UV Light recommendations wanted
> 
> Thanks, Doug☺On Mon, Jul 9, 2018 at 6:25 PM, Doug Bank <dougbank at alum.mit.edu> wrote:> John,>> Hyalite is definitely radioactive. In some cases, very radioactive. I just> measured a small piece from Spruce Pine, NC, and it is roughly 10-15x> background (in my basement outside of Chicago). It’s isn’t too bad, but I> have relocated most of the other hyalite and radioactive stuff to the> garage, so I do try to be careful with it. Some would say that I am> overreacting, but I don’t have the best set of genes, so better safe than> sorry.>> That said, 100 POUNDS? That is a completely different issue. If there is a> little hyalite on a lot of chalcedony, OK, but if it is a lot of hyalite,> then that is probably a lot of radioactivity. More importantly, it might> put out a lot of radon, and radon is the real problem, especially if you> put the hyalite in a poorly ventilated and below grade location. I trust> that others on this list can elaborate as to whether they would be OK with> 100 pounds of hyalite inside their house.>> Regarding the fluorescence, there are multiple options. Hyalite is often> incredibly fluorescent. The one I mentioned is in my long wave case, but it> is equally fluorescent (or better) under short wave and medium wave. It is> fluorescent using my old (but inferior) long wave light. It isn’t quite as> bright, but it is still plenty bright using a regular old black light bulb> that you can buy at Home Depot or, probably, Walmart. If you want to do it> right and produce enough green light to light up the entire room, then the> easiest solution is to visit ebay and buy a used, but working, UV> transilluminator. Those are typically midwave, but you could just use it as> such and get a great response. If you desired, you could buy new bulbs and> have a good short wave light (or long or full wave).>> For more information on this subject, visit this web page:> http://www.minershop.com/technology/diy-projects/transilluminators/ <> http://www.minershop.com/technology/diy-projects/transilluminators/>>> For more info on anything else related to fluorescence, there is a great> Facebook group: https://www.facebook.com/groups/fluorescentminerals/ <> https://www.facebook.com/groups/fluorescentminerals/>>> Good Luck!> Doug Bank>>> > On Jul 9, 2018, at 5:18 PM, John Scully <jscully216 at gmail.com> wrote:> >> > Hi, All> >> > I just purchased about 100 pounds of hyalite opal on chalcedony from> > Mexico.  Now I want to put it under a UV light.  So, I am asking for> > recommendations on what to purchase.  Questions such as:> >> > 1.  SW vs. LW?> > 2.  Flashlight size units?> > 3.  Larger units?> > 4.  Battery operated?> > 5.  Price range -- this is important to me.  anything useful at around> $200?> >> > Also, does hyalite have any radioactivity?> >> > Thanks> >> > John Scully> > _______________________________________________> > Rockhounds mailing list> > Subscription Services:  http://rockhounds.drizzle.com/> mailman/listinfo/rockhounds_rockhounds.drizzle.com> > List Usage Policy: http://Tomaszewski.net/Kreigh/> Rockhounds/Rockhounds.shtml>> _______________________________________________> Rockhounds mailing list> Subscription Services:  http://rockhounds.drizzle.com/> mailman/listinfo/rockhounds_rockhounds.drizzle.com> List Usage Policy: http://Tomaszewski.net/Kreigh/> Rockhounds/Rockhounds.shtml>_______________________________________________Rockhounds mailing listSubscription Services:  http://rockhounds.drizzle.com/mailman/listinfo/rockhounds_rockhounds.drizzle.comList Usage Policy: http://Tomaszewski.net/Kreigh/Rockhounds/Rockhounds.shtml
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