Odd experiment results with two old PCI Toners strikes safe dipping method?

Constantine

So I find this interesting....first of all, sorry I have no pics but before photos were never taken so it really does not help. Any rate, back in the very early 90s I was a young collector and sent in a 1989-S proof half and quarter to PCI. I saved up probably $20 and was so excited to do my first submission! They graded both 67 which I thought was conservative and a good sign on their part. However, I threw them in a box and over the years they toned to a very strong gold color. I know how the PCI insert or label can effect toning. But I thought since they were not valuable coins that I would sit them in the window sill to see what happens. I put tape over the label part of the holder knowing that the UV would fade it. However in only 60 days.......I am shocked that the gold toning is mostly gone!!! It was intense before and now barely noticeable. The UV from the sun did that?? It must have, but it was not expected.

So I was thinking.......could high intensity, manufactured, ultraviolent light be used to "dip" coins that have certain types of toning? Could this be a method that does not alter the coins surface from a chemical/stripping sense and thus be a good thing?

JamesM

I think that is a very interesting question I looked around for any information I could find on possible reactions. Both copper and silver can be reactive to light and I believe the sulfides of both could have a reaction with UV-light but to what level I do not know. But I do not believe the coins will stay white for long. If they toning on the coins was in fact from the formation of silver sulfides I think that although no longer on the coin the gas is still still inside the slab and will react with your coin quickly to make more silver sulfide

llafoe

After reading this, RickO will have all his coins on his window sills!

joebb21

summer is just around the corner!

robkool

Interesting...

Constantine

<< <i>summer is just around the corner! >>



Maybe I should patent a machine that brightens coins while providing a tan at the same time? In all seriousness though, the transformation from intense gold in a short period of time is amazing to me. I just wonder if specialized UV light could alter a coins appearance and be a "safe alternative" to dipping per se. Even if the case, I am sure there would be plenty of caveats such as type and reason of toning and coin composition etc. But at least from my unintentional experience, the sun whether it was the UV light or not, removed gold PCI toning from two clad coins! Also, for the record it did the opposite effect I had intended though. Wasn't Viagra invented accidently?

Redglobe

Hello,

In many ways that seems natural,sitting something in the sun for a period of time will fade or bleach it so to say.

Maybe the plastic case also could have sped up the process.

As the other poster mentioned the gas scenario does make sense.

Could heat at a certain point start to make a gas to "eliminate" the toning of the coin ?

Interesting for sure.

Rob

ricko

Never considered this.... interesting. Will have to experiment. Cheers, RickO

Constantine

<< <i>Hello,

In many ways that seems natural,sitting something in the sun for a period of time will fade or bleach it so to say.

Maybe the plastic case also could have sped up the process.

As the other poster mentioned the gas scenario does make sense.

Could heat at a certain point start to make a gas to "eliminate" the toning of the coin ?

Interesting for sure.

Rob >>



Considering I am in Oregon and the last couple of months have been the rainiest on record, the slabs certainly were not baked in the sun but just had what I would consider a normal dose of old fashioned fresh light sitting on the window sill.

PCcoins

I know that the gold toning you speak of is the start of rainbow toning. That is the first progression and it should continue to progress through the color spectrum.

I haven't heard of UV light doing the opposite and turning a coin white that was previously toned. I know the old PCI holders can turn the ASE's cirus rainbow colors, and they would be considered natural because the slab did the toning. And I'm not so sure it's just the paper label that does the toning anyways. I believe there's some chemical compound that's in their plastic slabs that is different than any other TPGs plastic. Because the ASE's will only rainbow tone with wild colors in the older PCI holders, not any other plastic holder.

And I was talking with a collector that had a really nice rainbow toned ASE in a PCI slab that said "white" on the label (as most of the rainbow PCI ASE's do), and he decided to crack the coin out and send to NGC to certify. But when he cracked the slab open he said there was a strong odor coming from inside the slab.

PCcoins

You would think if the coin had a layer of silver oxide on it that the only way to remove it would be a quick dip. Because the silver oxide is a thin layer of atoms (nanometers thick) on the coins surface that is bonded to the silver atoms of the coin.

We need TomB for an experts opinion.

leothelyon

Color exists only in the mind of the beholder.


Leo