Fossil Collecting Under Uv Light?

[Kosmoceras]

I am not sure if this is in the right place; please move as appropriate if wrong.

In a few months time I might get the chance to go collecting for shark teeth for a few days. Having to abide by the tides, I would like to try collecting at night as well to make the most of my time. I have heard around that shark teeth glow under UV light so it might be an option rather than a normal torch. If this is the case, what are the necessary safety precautions needed whilst using a UV torch?

http://www.thefossilforum.com/index.php?/topic/36343-uv-light-test-on-fossils/

I have been reading through some threads and found that you should have adequate eye protection, what sort would this be?

Many thanks for your thoughts,

Thomas

[snolly50]

Hello, none of the many sharks teeth in my possession are fluorescent. They are from the US, NC/SC. However, my brother; claims his SC collected teeth are fluorescent. The tube I currently have installed is "mid-wave UV," as my "short-wave" tube burned out. That may account for the difference. In my limited experience I have found more pieces (not shark's teeth) reactive to "short-wave." For an exception see my recent "Oreodont Prep Series" in the Forum's prep section.

Good luck with your future hunt.

[Scylla]

Depends on which UV wavelength you plan on using. If just UVA you probably will be OK with not pointing it into your eyes. If a higher energy (shorter wavelength) then a UV protective glasses or face shield would work. Link. You might want to test out your safety glasses that you already own, they might work. You test them by getting a florescent object and seeing if the lens blocks the UV light from your source and stops the florescence. Since you are collecting at night I assume your skin will be covered, if not get high SPF sunscreen with zinc oxide or titanium dioxide.

[Kosmoceras]

Thanks for your messages, I will need to do more tests. The teeth I hope to find come from the Eocene aged London Clay. I might bring some I have found in the past down to a shop which sells them where I might be able to test them under different wavelengths for short amounts of time and see if it works - if it does I will know what wavelength I would require.

Many thanks,

Thomas

[Taogan]

Hello Thomas, I have spent the last 10 minutes in the broom cupboard testing UV lights and it is time to come out, the wife wants the ironing board for some strange ritual involving the laundry basket. I have 3 UV lamps of various types because of a scorpion keeping obsession I used to have when I lived abroad and have tested them all and I haven't found any significant glow from any shark teeth from Sheppey, Abbey Wood, Bracklesham Bay or any of the Cretaceous teeth from the UK or Germany. What I do know is you can't use an ordinary light as well and you can't see where you are going with a UV lamp if you are wearing any sort of eye protection. In the past I have used UV to see crustacean and insect fossils, for example the decapods from Solnhofen and it works well with them, but not in the field because of the limits of the illumination, you either see where you are going or you see the fossil, doing both is a problem and depending on where you are planning to collect you might want to see where the bottomless pits of soft mud are. I would suggest a very bright normal light, the teeth do seem to reflect quite well, and you can see where you are going as well.

Stephen

[Kosmoceras]

It seems the tests have been done for me... thanks Stephen. I will look out for a more powerful normal torch as safety at the location is the priority with the tide. Many thanks for your help.

Case closed.

[Scylla]

... depending on where you are planning to collect you might want to see where the bottomless pits of soft mud are....

Is that because the fossils are found in the bottomless pits of soft mud?

[Auspex]

Is that because the fossils are found in the bottomless pits of soft mud?

Only recent ones...

[caldigger]

All the teeth I have collected from STH glow a yellowish- orange under short wave UV. I guess it all depends on what minerals they are exposed to.

Cheers and good luck on the hunt....of course we are going to want to see pics of your finds!

[obsessed1]

I'm not sure what varieties of lights you have at your disposal over there but here in the US the best light I have found is a "MagLite" flashlight with LED as the light source. It is 10 times better than a regular bulb as it gives off a more clean light (more like sunlight) rather than the more yellowish light from standard bulbs. I would suppose that any LED type light would be good as well.

[gdarone]

Just bought this guy from Amazon.com (and some UV safety goggles). Will let you know how it works, and if any of my fossil specimens glow, I'll be sure to post pics of them

http://www.amazon.com/dp/B001Q70A0G/ref=pe_385040_30332200_pe_309540_26725410_item

[gdarone]

All the teeth I have collected from STH glow a yellowish- orange under short wave UV. I guess it all depends on what minerals they are exposed to.

Cheers and good luck on the hunt....of course we are going to want to see pics of your finds!

I'll be sure to check the ones I got from your STH matrix for the orange glow

[gdarone]

My teeth from SharkTooth Hill do infact glow orangish/yellow under the UV light. Sorry about my poor low-light camera skills - my camera is not that good

Most of my other fossils do not seem to luminesce under the UV light, except several of my marine mammal fossils from Calvert Cliffs, MD.

This porpoise vertebra has a reddish/purplish glow to it in some spots, as do some rib fragments.

[Batty]

A very interesting topic....hubby just ordered a uv light to look for opal up north next week, I will make sure he wears safety glasses. I don't know the specs on the light yet as it hasn't arrived but will reading the instructions and precautions carefully before he uses it.

[caldigger]

Wow Greg, I would say you did pretty good with your photography. Just look at 'em glow! I tried taking picks of some of my fossils and the pictures would never come out. Then again my camera is more or less a point and shoot model that doesn't have any bells and whistles to speak of.

Say, are those dolphin teeth at the top of the first pic?

Edited April 24, 2014 by caldigger

[gdarone]

Wow Greg, I would say you did pretty good with your photography. Just look at 'em glow! I tried taking picks of some of my fossils and the pictures would never come out. Then again my camera is more or less a point and shoot model that doesn't have any bells and whistles to speak of.

Say, are those dolphin teeth at the top of the first pic?

I haven't gotten down to identifying and posting all my fossils from the recent STH material that you sent me, but if the teeth you mention are dolphin teeth, I'll believe you That was my guess, too.

[painshill]

Although I would be amazed if any torch of this type came without a safety instruction sheet of some kind, it’s unlikely that it would require anything beyond basic common sense. Don’t shine it directly into your own or anyone else’s eyes. If using for extended periods of time, wear a pair of UV amber safety glasses:

https://www.google.co.uk/#q=uv+amber+safety+glasses

As Taogan says, wearing those glasses ain’t gonna help much if you’re stumbling around in the dark… and that would also probably be considerably more hazardous than any UV exposure.

Even prolonged use of these kinds of torches would probably have no more effect than headaches and eye-strain, leading to drowsiness… another concern if you were driving home after a late night. Although the light from the torch may appear to be bright, your pupils will remain dilated in night conditions and that tires out the retina.

It’s pretty unlikely that a moderately-priced battery powered UV torch would generate more than 1 or 2 watts of output in total and it’s not likely to produce anything significant at the short wave (UV-C) end. Most of them are long wave UV-A sources with a wavelength around 365-390nm and even if you spent a lot of money you’re still unlikely to get much more than about 10 watts of output.

To put that in context, a typical home sun-bed would probably have a dozen or more tubes, each of which are in excess of 100 Watts, emitting principally UV-A wavelengths. A professional tanning salon might give you double that exposure with a small proportion of UV-B. Neither would give you any UV-C exposure and that’s the dangerous end.

More info here:

http://www.thefossilforum.com/index.php?/topic/41049-fluorescent-fossils-under-uv-light/

Good luck to all those who try and keep safe.

Edited April 24, 2014 by painshill

[Pilobolus]

Although I would be amazed if any torch of this type came without a safety instruction sheet of some kind, it’s unlikely that it would require anything beyond basic common sense. Don’t shine it directly into your own or anyone else’s eyes. If using for extended periods of time, wear a pair of UV amber safety glasses:

https://www.google.co.uk/#q=uv+amber+safety+glasses

As Taogan says, wearing those glasses ain’t gonna help much if you’re stumbling around in the dark… and that would also probably be considerably more hazardous than any UV exposure.

Even prolonged use of these kinds of torches would probably have no more effect than headaches and eye-strain, leading to drowsiness… another concern if you were driving home after a late night. Although the light from the torch may appear to be bright, your pupils will remain dilated in night conditions and that tires out the retina.

It’s pretty unlikely that a moderately-priced battery powered UV torch would generate more than 1 or 2 watts of output in total and it’s not likely to produce anything significant at the short wave (UV-C) end. Most of them are long wave UV-A sources with a wavelength around 365-390nm and even if you spent a lot of money you’re still unlikely to get much more than about 10 watts of output.

To put that in context, a typical home sun-bed would probably have a dozen or more tubes, each of which are in excess of 100 Watts, emitting principally UV-A wavelengths. A professional tanning salon might give you double that exposure with a small proportion of UV-B. Neither would give you any UV-C exposure and that’s the dangerous end.

More info here:

http://www.thefossilforum.com/index.php?/topic/41049-fluorescent-fossils-under-uv-light/

Good luck to all those who try and keep safe.

Although there are multiple threads touching on this subject, I decided to post within this one because it seems to have the most recent discussion, and "collecting gear" seems an appropriate heading.

In Painshill's link (quoted) the paper he posts has some interesting results which I think can be synopsized thus:

1) A two-part study regarding the efficacy of using UV to seek out fossils was undertaken (a) to see of field museum specimens fluoresce (some did, some did not, and enamel on teeth, eggshell frags did better than most bones); and a field test of UV on plots either searched as-is or seeded with known positives, both in daylight hours and at night with UV.

2) The net result is that slightly more small teeth/teeth fragments could be found at night with UV but that while significant, it is not known how transferable this is to other sites/fossil types. This is why they then looked at field museum samples, and discuss the fossil features that impact fluorescence .

3) there were some interesting applications to field collecting fossils with UV including eggshells, and osteoderms that some might find useful, and a good section on wavelength considerations and safety concerns.

4) My own assessment is that it would be fun to try out, but without a powerful UV that would allow me to see items in the erect position, I think being on one's hands and knees and eye and back fatigue makes this an unlikely pursuit for me.

[Pilobolus]

That being said, I decided to look at my very limited collection of teeth with a portable UV unit I had, which, while portable, is too weak to use in the field unless on hands and knees.

Edited September 4, 2014 by Pilobolus

[Pilobolus]

This tooth had high gloss enamel present, which made it easy to find:

[Pilobolus]

...the lingual surface of the same tooth had less enamel (more weathered?) and thus less impressive fluorescence:

[Pilobolus]

A small collection of teeth had little to no fluorescence owing to little or no enamel. Ptychodus teeth did not show, but an ammonite, probably with some calcite coating, showed dull orange:

Edited September 4, 2014 by Pilobolus

[Harry Pristis]

Produced with the 51-led UVA flashlight mentioned in this thread.

[caldigger]

Beautiful photography Harry.

[Pilobolus]

Harry:

Have you tried this light in the field? Or faked it by dropping your samples among the weeds to see if you could pick it out at a distance?