Long Term Storage Of Silver Coins

to the CCF!
Moisture and oxygen are your enemies and it sounds like you're on the right track. How have the coins fared so far? If they aren't corroding now, you might want to consider just leaving well enough alone. You do want to keep them stashed in a low humidity environ, though. My only other concern might be that the softeners used to make the shrink wrap plastics could interact with you metal. However, I believe that would mostly affect copper. Sterling is 7.5% copper, isn't it?

BTW, how long is long term? Can you give us some background on these coins (cuz we're really curious about all coins)? inherited? Bought as investment? Found?

Silver coins are less sensitive to toning than copper or bronze coins.
Nevertheless, I have never seen a blast white MS65 silver coin that is perhaps 300 years old.

Ancient silver coins may suffer from the problems of horn silver or silver crystallization.
Copper or bronze coins do nor suffer from either of these problems.

PVC will ruin coins. Been there, done that, stored them, got them out, cried some!

Acetone MAY work on these; it would certainly be worth a try.
I agree the the green is most probably due the the PVC, but I an not sure of the chemistry.

With soft clear PVC, it is not the Poly Vynyl Chloride that is the problem, it is the softening plastizer oils that leach out and react with the metal in the coin alloy. They may? form partly oraganic / inorganic metallic complexes, which may be susceptible the solvent abilities of acetone.

Coins pictured are 50% silver quaternary* metal. Perhaps pre 1945 Australian .925 sterling silver coins may be a little more resistant to greening in this way.

*50% silver, 40% copper, 5% nickel, 5% zinc.

coaster

It's most likely that the coins were put into the album in the condition they are in. The early type of coin albums
- 1970's , etc - usually came with a white paper backing sheet between each of the plastic pages. On each of the white paper backing sheets, there was usually ruled lines aligned behind each of the album's coin pockets so that details of the coin inside each of the pockets - the country, year, denomination and grade/ condition - could be written.

Luckily, these white paper backing sheets - I have one in front of me now while I write this - acted as protector of the coins within the plastic pocket sheets of the album, because the plastic pocket sheets in the album couldn't come into contact with each other as a result of these white paper backing sheets being between each of the pages of plastic coin pockets.

It is important that any album(s) are stored standing upright, and never flat, especially is there isn't any eg. a sheet of photocopy paper, or similar, between each and every one of the plastic pocket sheets. Definitely a must.

I won't store any coins, especially $1, $2, copper coins or pre decimal coins, in albums with plastic pockets, although they are in 2 x 2 holders. The Australian decimal " silver " coins are usually ok in albums, if preferred.

Hope the above helps you.

I have to disagree with that.
Storing your albums upright puts a strain on the pages as they sag against the binder hinges and will eventually damage them.
Also if you are using self adhesive 2x2's there is also the likelihood of the coins gravitating down into the adhesive.
Storing the albums flat eliminates this.
Storing your albums flat will Not in any way damage your coins and neither should the coins in their 2x2's or saflips work their way out of the pages.
Also when buying albums and pages make absolutely sure that there is NO PVC in the pages AND the album cover and sleeve.

The problem with PVC is that it "Gasses out" and the Only way to prevent contamination is to completely remove the coins from any possible PVC source, Just separating the pages with paper won't do any good in the long run.
Many of us have gone down the path of the cheap and nasty PVC albums to our ultimate regret But in reality it is Not that much more expensive to buy the good quality NON PVC albums and pages in the first place and you don't have to face the horrible sight of your favourite coins covered in that awful green slime.
The best advice I can give you is to ditch the PVC rubbish and get some decent non PVC albums and pages for your coins

Decimal coins are also be affected by PVC. I have many hundreds of coins that feel like someone has spilt jelly over them. Mostly 10c, but also some 20c & 50c.

Soaking them all in Acetone is going to be a huge job, so I might just send them all back to the pond and chalk it up to experience.

Don't allow PVC to get within cooee of any coins.