Why do some fossils glow in UV light?

[joaoarguello3]

Hello everyone, greetings and a big hug. I have already been reviewing the entire section for a few days. Is it real? and something caught my attention. In some specific cases of certain fossils they recommended using UV light to see if the fossil is real. (got the part about real fossils glowing while fake parts or the entire fake or painted fossil don't) The coolest example was of a crustacean in the genus Aeger where someone posted one that was completely fake and didn't glow at all UV light (obviously being a paint). I have a couple of questions about it.

 

 

-Can this be done with all kinds of fossils or just with some?
-Why is this happening? Is it because of the composition and if so, what type of composition do they have to have or what type of material is it that shines?
-What kind of UV light is it? since the UV spectrum is very broad and they may only shine at a certain frequency of the UV spectrum and not at all, as is the case with some minerals that only shine at a certain UV frequency.

[Mark Kmiecik]

I think you have it backwards. The fossils don't glow, but any repairs or glue should glow brightly.

[DPS Ammonite]

8 minutes ago, Mark Kmiecik said:

I think you have it backwards. The fossils don't glow, but any repairs or glue should glow brightly.

The fossils, matrix and the repair medium can all glow or not glow. You look at fluorescence to see if it is original to nature or if it has been repaired or altered by man. 
 

Silica fossils often are yellowish green due to uranium. Carbonate fossils can be many different colors due to impurities in the carbonate. Glues and repair mediums can also glow. 
 

For more complete explanation about why rocks and minerals fluoresce see Mindat or the Fluorescent Mineral Society.

[Troodon]

Some fossils are fluorescent.  Attached find an article that indicates why that occurs. 

 

UV lights on repairs typically look to get a reaction from the paint that is used to cover the repair or resto.  Some types of paint may not fluoresce but thats beyond my expertise

 

https://cen.acs.org/articles/95/i4/Fluorescing-fossils-graffitied-gorges.html#:~:text=The fossils fluoresce as a,around in its molecular lattice.

[joaoarguello3]

Gracias a todos por sus respuestas. Entonces, ¿eso significa que no todos los fósiles brillan con luz ultravioleta? ¿Se puede aplicar cualquier tipo de luz en el caso de los que sí? Y finalmente, ¿no es un motivo que demuestra plenamente la autenticidad de un fósil en particular? ....aqui les dejo el link del foro donde vi la luz ultravioleta en fosiles

 

http://www.thefossilforum.com/index.php?/topic/123389-shrimp-looks-too-good/

[DPS Ammonite]

Translation from Google. I changed motif to reason; hopefully that works.

 

“Thanks to everyone for your replies. So does that mean not all fossils glow in ultraviolet light? Can any type of light be applied in the case of those that can? And finally, isn't it a reason that fully demonstrates the authenticity of a particular fossil? ....here I leave the link of the forum where I saw ultraviolet light in fossils.”

 

Not all fossils glow in ultraviolet light (UV). Fossils can respond in any combination to the 3 types of UV light: long, mid and short.

UV light response is a tool to help with ID. Sometimes it determines the authenticity of a fossil, most times it does not.

 

 

Edited July 2, 2022 by DPS Ammonite

[FranzBernhard]

1 hour ago, DPS Ammonite said:

So does that mean not all fossils glow in ultraviolet light?

Yes. Sometimes, only some parts are glowing, revealing long-gone color patterns:

Franz Bernhard

Edited July 2, 2022 by FranzBernhard

[Coco]

A publication of my friend Jean-Michel Pacaud, unfortunalty in french.

 

https://olivirv.myspecies.info/sites/olivirv.myspecies.info/files/Les mollusques eocenes se devoilent sous ultraviolets Saint Martin%2C J.-P. (Jean-Paul) %26 Pacaud%2C Jean-Michel.pdf

 

Coco

[DPS Ammonite]

That was a great post Franz. Too bad patterns can’t be seen in Paleozoic fossils in Arizona. 
 

Does anyone know if any Paleozoic fossils show original exterior color patterns visible to UV light?

Edited July 2, 2022 by DPS Ammonite

[DPS Ammonite]

Oh jeez, I found an old post that I made about color patterns visible in Devonian fossils. I don’t know without reading it if some were only visible using UV light: probably.

 

A quick read does not find that the researchers in paper below used a UV lamp. Maybe someone needs to look at the fossils again.

 

 

Edited July 2, 2022 by DPS Ammonite

[DPS Ammonite]

36 minutes ago, Coco said:

A publication of my friend Jean-Michel Pacaud, unfortunalty in french.

 

https://olivirv.myspecies.info/sites/olivirv.myspecies.info/files/Les mollusques eocenes se devoilent sous ultraviolets Saint Martin%2C J.-P. (Jean-Paul) %26 Pacaud%2C Jean-Michel.pdf

 

Coco

 

My French is not to good. Are there any shells in this paper that look the same except for an exterior color pattern and are then given separate species names? 
 

A broader question, are there any fossils that have different species names based solely on exterior color patterns that otherwise are identical? Maybe some of the newest Pio/Pleistocene species could be excluded since they often still have color. @FranzBernhard

Edited July 2, 2022 by DPS Ammonite

[Coco]

A fast translation of "page 17" :

 

Three different types of records were distinguished: (1) residual colour patterns visible in light natural on a diagenetized shell; (2) colorful patterns visible in natural light and preserved in a “native” state; (3) residual color patterns invisible in natural light but which can be revealed by exposure under ultraviolet light. Preserving the pattern through chemical transformation of the shell and pigments (diagenesis) is at the origin of the most of the residual colorations that could be observed in different groups of molluscs. In the Cenozoic, some fossils show colorful patterns such that can be observed in the present representatives, known as preserved in the “native” state. This is the case with gastropods of the family Neritidae (fig. 3:E), known long ago as being carriers of colorful patterns. The fossil specimens with a pattern preserved through of one of these first two types of record remain however not enough to evoke their use in the distinction and characterization of species. By therefore, they were very rarely taken into account as a viable tool in Paleontology.

 

Coco

[FranzBernhard]

15 minutes ago, DPS Ammonite said:

are there any fossils that have different species names based solely on exterior color patterns that otherwise are identical?

Sorry, no idea. I have it the other way round: The three cones posted above have all very different "outlines", but similar patterns. I asked the first author of K. hendricksi, what he thinks about these three specimens. He said, he has no better idea than that all are the same species.

Franz Bernhard

[joaoarguello3]

Thanks to everyone for your replies. I certainly learned a lot from everything you shared. He certainly did not know that with ultraviolet light one could discover patterns not present visible to the naked eye.