Log in or Sign up
Coin Talk
Home
Forums
>
Coin Forums
>
US Coins Forum
>
US Mint Silver Proof Set Yellowing Issues
>
Reply to Thread
Message:
<p>[QUOTE="Paul M., post: 5306854, member: 73165"]I beg to differ. It <i>is</i> most certainly possible to stop toning entirely. The issue is that nobody is really going to go to the trouble to do it due to the utter impracticality of it.</p><p><br /></p><p>What you'd have to do is store the coins in a hermetically sealed box under a dry nitrogen atmosphere. You can't store them in a safe, or exposed to open air, or even vacuum sealed inside plastic bags and hope to stop toning. You have to keep the stuff that causes toning out entirely, and that's pretty much the atmosphere.</p><p><br /></p><p>Nitrogen isn't completely inert, but there are no direct reactions between silver, copper, or gold and nitrogen gas that will happen at anything close to room temperature. We're talking well over 1500 degrees C before anything fun happens, and, by that time, your coins are melted anyway.</p><p><br /></p><p>While I've never heard of it, it's not <i>entirely</i> crazy that, say, a museum might store certain items under dry nitrogen like this. Original copies of the Declaration of Independence, Articles of Confederation, and the Constitution are <a href="https://www.nps.gov/inde/learn/historyculture/conserving-the-great-essentials.htm" target="_blank" class="externalLink ProxyLink" data-proxy-href="https://www.nps.gov/inde/learn/historyculture/conserving-the-great-essentials.htm" rel="nofollow">stored at Independence Hal</a>l, under argon in a precisely climate controlled environment, including sufficient humidity to keep the paper from cracking.</p><p><br /></p><p>I suppose you could object that this doesn't really stop toning entirely, but, with proper maintenance of the system, I see no literal reason why you couldn't keep copper mint red for thousands of years under these conditions. That, to me, effectively amounts to stopping the toning process.[/QUOTE]</p><p><br /></p>
[QUOTE="Paul M., post: 5306854, member: 73165"]I beg to differ. It [I]is[/I] most certainly possible to stop toning entirely. The issue is that nobody is really going to go to the trouble to do it due to the utter impracticality of it. What you'd have to do is store the coins in a hermetically sealed box under a dry nitrogen atmosphere. You can't store them in a safe, or exposed to open air, or even vacuum sealed inside plastic bags and hope to stop toning. You have to keep the stuff that causes toning out entirely, and that's pretty much the atmosphere. Nitrogen isn't completely inert, but there are no direct reactions between silver, copper, or gold and nitrogen gas that will happen at anything close to room temperature. We're talking well over 1500 degrees C before anything fun happens, and, by that time, your coins are melted anyway. While I've never heard of it, it's not [I]entirely[/I] crazy that, say, a museum might store certain items under dry nitrogen like this. Original copies of the Declaration of Independence, Articles of Confederation, and the Constitution are [URL='https://www.nps.gov/inde/learn/historyculture/conserving-the-great-essentials.htm']stored at Independence Hal[/URL]l, under argon in a precisely climate controlled environment, including sufficient humidity to keep the paper from cracking. I suppose you could object that this doesn't really stop toning entirely, but, with proper maintenance of the system, I see no literal reason why you couldn't keep copper mint red for thousands of years under these conditions. That, to me, effectively amounts to stopping the toning process.[/QUOTE]
Your name or email address:
Do you already have an account?
No, create an account now.
Yes, my password is:
Forgot your password?
Stay logged in
Coin Talk
Home
Forums
>
Coin Forums
>
US Coins Forum
>
US Mint Silver Proof Set Yellowing Issues
>
Home
Home
Quick Links
Search Forums
Recent Activity
Recent Posts
Forums
Forums
Quick Links
Search Forums
Recent Posts
Competitions
Competitions
Quick Links
Competition Index
Rules, Terms & Conditions
Gallery
Gallery
Quick Links
Search Media
New Media
Showcase
Showcase
Quick Links
Search Items
Most Active Members
New Items
Directory
Directory
Quick Links
Directory Home
New Listings
Members
Members
Quick Links
Notable Members
Current Visitors
Recent Activity
New Profile Posts
Sponsors
Menu
Search
Search titles only
Posted by Member:
Separate names with a comma.
Newer Than:
Search this thread only
Search this forum only
Display results as threads
Useful Searches
Recent Posts
More...