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 Replies: 13 / Views: 2,589 |
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Pillar of the Community
United States
564 Posts |
There are milk spots on my silver maple what should I do?
Diem
*** Moved by Staff to a more appropriate forum. ***
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Moderator
 United States
56855 Posts |
Sell it and get a better one. Milk spots do not come off without damaging the coin. John1  |
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Pillar of the Community
Canada
5239 Posts |
The silver maples are notorious for these, and I have not hard of anything that can be done.
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Pillar of the Community
United States
3468 Posts |
If you just received it from the RCM, send it back for a replacement. |
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Pillar of the Community
 United States
564 Posts |
Sadly I had it for a monthish have already.
Edited by Justinokay
04/29/2017 12:24 pm
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Pillar of the Community
United States
1757 Posts |
I forget but milk spots are derived from either a sulfur or chlorine surface contaminant type compounds the two major elements from environmental exposure (i.e., Cl & S). So as they say ABOVE nothing to do but return it or live with it. Its part of the metal surface like carbon spots on copper. There is an analysis somewhere which in that discussion the milk spots were on gold issues - but again not sure if a sulfur or chlorine type compound was confirmed by Material Analysis.
John Lorenzo
Numismatist
United States
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Valued Member
United States
426 Posts |
Quote:
The silver maples are notorious for these, and I have not hard of anything that can be done. Sadly this why I stopped collecting the Maple's, the milk spots were just too much of an eyesore for me. |
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Valued Member
United States
262 Posts |
Edited by PatAR
04/29/2017 2:52 pm
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Pillar of the Community
United States
1757 Posts |
AgCl may also be AuCl - If someone contacts/sends me a cheap bullion milk spotted coin I will run more analysis in my lab. Could not remember if was a sulfide or chloride issue. I will also try my Cu cleaner that I developed JPL Coin Care. Theoretically if its just on the surface it should remove milk spots. Swiatek's recommendation of acetone is STUPID. There are many more advanced chemicals for sensitive surfaces like copper. http://www.perthmintbullion.com/us/...t_Issue.aspxJohn Lorenzo (M.S. Chemistry) Numismatist United States |
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Valued Member
United States
262 Posts |
John,
My understanding is that it is actually potassium bitartrate KC4H5O6 (commonly referred to as cream of tartar) which can be mixed with acidic solutions to clean metals. I believe many world mints use this to bring a shine to the silver planchets during the wash/rinse/dry process. Whether this remains on the coin or causes a chemical reaction that later results in a milk spot is unknown.
Nevertheless, would be great to see what your lab analysis might reveal!
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Valued Member
Canada
217 Posts |
Just wondering, if a silver maple has extensive milkspots all over the surfaces, do those chemical contaminants reduce the 99.99 purity?
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Valued Member
Canada
343 Posts |
Another vote for why I stopped collecting maples - too many milk spots. Same with their wildlife series - really disappointing. Never had issues with Libertads or anything from the Perth Mint. |
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Pillar of the Community
United States
1609 Posts |
Rockfish, I wouldn't normally be the one to say, but I seriously doubt that something as (mass wise) miniscule as a milk spot would be able to affect the purity to the hundredth of a percent. Now, if you're talking ten thousandth or hundred thousandth of a percent, I wouldn't be surprised.
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Pillar of the Community
United States
4211 Posts |
Milk spots are just something we have to put up with collecting silver bullion coins.
I have spotted Maples, Britannias, Philharmonics, Bundi Lions and the list goes on and on.
It's still an ounce of silver.
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Replies: 13 / Views: 2,589 |
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Posted 04/29/2017 06:17 am
