Black spot disease of cents

Che_Grapes

This black spot issue has seemingly appeared to infect some of my Lincoln cents (Indians seem immune!) - what you say?
And what is the best “cure”?

PerryHall

With cardboard staple holders, before using, you should clean the inside windows which usually has cardboard dust from the manufacturing process. Over time, this cardboard dust can react with the surfaces of your coin. I usually just wipe the inside of the holder with a soft cotton cloth or spray the inside windows with compressed air.

jmlanzaf

There is no cure. Laser ablation for a 1792 disme. Too expensive for most coins.

Indianlincoln

It’s a cancer

Mr_Spud

Heat sealed saflips work pretty good to help prevent them. You can seal saflips with a cheap impulse sealer

Namvet69

Yup, that corrosion is disturbingly nasty looking.

coinbuf

No remedy, that coin is now ruined.

Che_Grapes

Well I feel better now!
(Not!)

But appreciate all the comments

dsessom

@Che_Grapes This is an interesting topic in which I have done experiments with. My girlfriend/partner of 12 years is a biological chemist who works as Chief Chemist at a wastewater treatment plant. She was gracious enough to assist me in a numismatic experiment recently, in which we took several silver, copper, and nickel coins (all pre-1964) and sat them in a sterile tray, open to the air. If you have never visited a wastewater treatment plant, consider yourself lucky. It smells horrid, and the reason it smells so bad is because of the high concentration of sulfur, in the form of hydrogen sulfide gas, that is in the air.

After only a few days, the copper coins turned dark. After a few weeks, they were nearly black. The silver and nickel coins seemed unaffected. After a month, the copper was completely black and the silver and nickel were still seemingly unaffected. The experiment showed that copper reacts quickly to exposure to sulfur - by turning black.

2X2 flips are made of PVC and cardboard. The cardboard contains small amounts of sulfur. As stated above, the dust from the cardboard flips can and probably will create black specs on shiny copper. The above explains why. It's very unfortunate that the flip we use to protect our coins can actually damage them, but they can. (Not to mention PVC damage)

Unfortunately, the damage is not reversible.

Steven59

Ah Ha! Here's your culprit!

Steven59

[ And what is the best “cure”? ]

jesbroken

Sorry, but the coin is ruined. Even if removal of the black spots was successful, there would be damage underneath which would also ruin the coins look and therefore value.
Jim

skier07

I have the same problem with beetles attacking cigars in my humidor.

Omegaraptor

Yup. Cardboard dust is probably the culprit.

Here's a coin I have. It cost me $8. An RB/RD UNC 1928-S Lincoln... damn shame.

johnny9434

Covid for coins 😪

BillJones

@Steven59 said:
Ah Ha! Here's your culprit!

This is not far fetched. Sneezing over a coin or even talking over it can inadvertently result in drops of saliva getting on the piece which can cause spots. That’s why it’s best to cover the piece when the negotiations for the sale begin. Of course, slabs take care of this problem.

ricko

Those spots, even if removed (doubt it can be done without further issues), would leave an unsightly mark. For special raw coins of mine, I give them an acetone bath and then seal them in either self slab or cointain.... and I also blow out whichever I use with compressed air. Cheers, RickO

bagofnickels

I don't really have much to add except to say this kind of thing is what scared me away from collecting raw copper. I also when I put my coins into 2x2s wipe the inside window with the back of my glove or a microfiber towel like you might use for glasses or I tap it to see if any of the dust is on the inside or outside.

lilolme

@dsessom said:
@Che_Grapes This is an interesting topic in which I have done experiments with. My girlfriend/partner of 12 years is a biological chemist who works as Chief Chemist at a wastewater treatment plant. She was gracious enough to assist me in a numismatic experiment recently, in which we took several silver, copper, and nickel coins (all pre-1964) and sat them in a sterile tray, open to the air. If you have never visited a wastewater treatment plant, consider yourself lucky. It smells horrid, and the reason it smells so bad is because of the high concentration of sulfur, in the form of hydrogen sulfide gas, that is in the air.

After only a few days, the copper coins turned dark. After a few weeks, they were nearly black. The silver and nickel coins seemed unaffected. After a month, the copper was completely black and the silver and nickel were still seemingly unaffected. The experiment showed that copper reacts quickly to exposure to sulfur - by turning black.

2X2 flips are made of PVC and cardboard. The cardboard contains small amounts of sulfur. As stated above, the dust from the cardboard flips can and probably will create black specs on shiny copper. The above explains why. It's very unfortunate that the flip we use to protect our coins can actually damage them, but they can. (Not to mention PVC damage)

Unfortunately, the damage is not reversible.

Interesting test, thanks.

The part on the 2X2 flips - The ones I found advertise that they are mylar. Don't know if there are some very old ones with PVC but I don't recall that.

Glen2022

Looks like the black plague to me. Cure: don't know, prevention, stay away from rats.

jmlanzaf

@lilolme said:

@dsessom said:
@Che_Grapes This is an interesting topic in which I have done experiments with. My girlfriend/partner of 12 years is a biological chemist who works as Chief Chemist at a wastewater treatment plant. She was gracious enough to assist me in a numismatic experiment recently, in which we took several silver, copper, and nickel coins (all pre-1964) and sat them in a sterile tray, open to the air. If you have never visited a wastewater treatment plant, consider yourself lucky. It smells horrid, and the reason it smells so bad is because of the high concentration of sulfur, in the form of hydrogen sulfide gas, that is in the air.

After only a few days, the copper coins turned dark. After a few weeks, they were nearly black. The silver and nickel coins seemed unaffected. After a month, the copper was completely black and the silver and nickel were still seemingly unaffected. The experiment showed that copper reacts quickly to exposure to sulfur - by turning black.

2X2 flips are made of PVC and cardboard. The cardboard contains small amounts of sulfur. As stated above, the dust from the cardboard flips can and probably will create black specs on shiny copper. The above explains why. It's very unfortunate that the flip we use to protect our coins can actually damage them, but they can. (Not to mention PVC damage)

Unfortunately, the damage is not reversible.

Interesting test, thanks.

The part on the 2X2 flips - The ones I found advertise that they are mylar. Don't know if there are some very old ones with PVC but I don't recall that.

Newer flips tend to be mylar, but PVC flips still exist. The mylar ones are fine.

lilolme

@jmlanzaf said:

@lilolme said:

@dsessom said:
@Che_Grapes This is an interesting topic in which I have done experiments with. My girlfriend/partner of 12 years is a biological chemist who works as Chief Chemist at a wastewater treatment plant. She was gracious enough to assist me in a numismatic experiment recently, in which we took several silver, copper, and nickel coins (all pre-1964) and sat them in a sterile tray, open to the air. If you have never visited a wastewater treatment plant, consider yourself lucky. It smells horrid, and the reason it smells so bad is because of the high concentration of sulfur, in the form of hydrogen sulfide gas, that is in the air.

After only a few days, the copper coins turned dark. After a few weeks, they were nearly black. The silver and nickel coins seemed unaffected. After a month, the copper was completely black and the silver and nickel were still seemingly unaffected. The experiment showed that copper reacts quickly to exposure to sulfur - by turning black.

2X2 flips are made of PVC and cardboard. The cardboard contains small amounts of sulfur. As stated above, the dust from the cardboard flips can and probably will create black specs on shiny copper. The above explains why. It's very unfortunate that the flip we use to protect our coins can actually damage them, but they can. (Not to mention PVC damage)

Unfortunately, the damage is not reversible.

Interesting test, thanks.

The part on the 2X2 flips - The ones I found advertise that they are mylar. Don't know if there are some very old ones with PVC but I don't recall that.

Newer flips tend to be mylar, but PVC flips still exist. The mylar ones are fine.

Interesting. As far as the 2X2 cardboard flips that were being discussed I didn't know that there were some with PVC in them.

Now the other pocket flips did have some or a lot of them with PVC and I did a clean up thread on these and even the 3 ring binder pages that hold them had PVC in them.

Edit - I went digging into one of the old boxes and found these. Maybe other old 2X2 were not mylar but at least I was recalling the ones I was familiar with correctly. Don't know how old these are but saying decades would probably work.

MasonG

Here's a 2x2 with pvc. Don't know if the holder was made of it or it was on the coin and got on the holder.

oreville

Adding and immersing the coin with unscented mineral oil will help to stop further growth of the black spots and might even slightly reduce some of the smaller and lighter spots. Had such coins been coated with such mineral oil it might have been a shield against such damage. Important to remember not to let the mineral oil dry out.

Che_Grapes

One interesting observation is that only the Lincoln’s are getting these spots - but the Indians and more modern zinc cents don’t have the disease … all were put in the same flips from my dads collection…

renomedphys

I’m no chemist, but I have heard it said that coins that have been chemically dipped and not properly rinsed are more prone to this sort of damage.

oreville

@renomedphys said:
I’m no chemist, but I have heard it said that coins that have been chemically dipped and not properly rinsed are more prone to this sort of damage.

Definitely. But it is not the only causal factor.

privatecoin

All the mint sets I've gone through I'd say 50% have black spots already in the cello.

MasonG

@renomedphys said:
I’m no chemist, but I have heard it said that coins that have been chemically dipped and not properly rinsed are more prone to this sort of damage.

In the case of the coin in the first post, a dip seems unlikely. How do you dip a coin and improperly rinse it such that you get such well-defined spots?

jmlanzaf

@MasonG said:

@renomedphys said:
I’m no chemist, but I have heard it said that coins that have been chemically dipped and not properly rinsed are more prone to this sort of damage.

In the case of the coin in the first post, a dip seems unlikely. How do you dip a coin and improperly rinse it such that you get such well-defined spots?

Liquid will bead around particulates on the surface.

MasonG

@jmlanzaf said:

@MasonG said:

@renomedphys said:
I’m no chemist, but I have heard it said that coins that have been chemically dipped and not properly rinsed are more prone to this sort of damage.

In the case of the coin in the first post, a dip seems unlikely. How do you dip a coin and improperly rinse it such that you get such well-defined spots?

Liquid will bead around particulates on the surface.

That sounds like an improper dip, not an improper rinse.

And then, there's this:

"All the mint sets I've gone through I'd say 50% have black spots already in the cello."

Those were probably not dipped or rinsed.

Just sayin'.

edited to add... "Improper rinse" seems to be one of the go-to responses here for anything having to do with odd toning or corrosion on coins. I'm skeptical.

jmlanzaf

@MasonG said:

@jmlanzaf said:

@MasonG said:

@renomedphys said:
I’m no chemist, but I have heard it said that coins that have been chemically dipped and not properly rinsed are more prone to this sort of damage.

In the case of the coin in the first post, a dip seems unlikely. How do you dip a coin and improperly rinse it such that you get such well-defined spots?

Liquid will bead around particulates on the surface.

That sounds like an improper dip, not an improper rinse.

And then, there's this:

"All the mint sets I've gone through I'd say 50% have black spots already in the cello."

Those were probably not dipped or rinsed.

Just sayin'.

edited to add... "Improper rinse" seems to be one of the go-to responses here for anything having to do with odd toning or corrosion on coins. I'm skeptical.

It can be either or both. Liquid does not evaporate uniformly over a dirty surface. As it pools and dries, the concentration of dissolved materials increases in the ever smaller beads. This is why dishes can spot in a dishwasher rather than end up uniformly cloudy.

I am simply explaining how spotting can happen in an improper rinse. There are numerous ways to get black spots, not just one. Anyone who thinks they know exactly how those spots came to be is kidding themselves.

MasonG

@jmlanzaf said:
Liquid does not evaporate uniformly over a dirty surface. As it pools and dries, the concentration of dissolved materials increases in the ever smaller beads. This is why dishes can spot in a dishwasher rather than end up uniformly cloudy.

That's why I said it sounds like an improper dip. A proper dip wouldn't result in dirty surfaces, would it?

jmlanzaf

@MasonG said:

@jmlanzaf said:
Liquid does not evaporate uniformly over a dirty surface. As it pools and dries, the concentration of dissolved materials increases in the ever smaller beads. This is why dishes can spot in a dishwasher rather than end up uniformly cloudy.

That's why I said it sounds like an improper dip. A proper dip wouldn't result in dirty surfaces, would it?

It may or may not. "Dip" could be several things, but none of them remove everything on the surface.

Che_Grapes

Anyone able to speculate why the Indians in the same flips and same box (for 40 plus years) yet they don’t have any black spots ….??!??!???
Under exact same conditions none of the Indians have spots yet ~74% of the Lincoln cents have spots ….!!

OldIndianNutKase

Your resolution is to buy a slabbed 1950-D. Without spots. The black spots on the coin are beyond redemption. You are free to try a number of remedies……you do not have much to lose.

Mr_Spud

Red copper is more unstable than brown, the older coins might have thicker “skin”

jmlanzaf

@Che_Grapes said:
Anyone able to speculate why the Indians in the same flips and same box (for 40 plus years) yet they don’t have any black spots ….??!??!???
Under exact same conditions none of the Indians have spots yet ~74% of the Lincoln cents have spots ….!!

I don't think the flios or box are the problem. Can i guess that the Indians are brown and circ?