milk spots
inthedark
Posts: 65
Hi all,
I have read a few posts about how silver coins can develop "milk spots".
The pictures aren't pretty.
As a new collector I want to steer clear of this possibility.
Does the same happen to gold/platinum coins?
thanks
Frank
I have read a few posts about how silver coins can develop "milk spots".
The pictures aren't pretty.
As a new collector I want to steer clear of this possibility.
Does the same happen to gold/platinum coins?
thanks
Frank
0
Comments
<< <i>I'm no expert in this field, but it is mostly a problem with silver coins. It is caused by the minting process and will only show up over time, I do not know if it can be avoided. >>
There also seems to be some correlation between humidity and temp control as to the occurance and amount of milkspotting (at least in the ASEs). I am not sure it's been well studied, but it seems like most of the posts I've read about, indicate that they are happening in more humid environs.
clarkbar04, this thread about Kennedy spots may be useful. "A quick dip to stabilize the surfaces" is the conclusion of it.
I think the same could be said for the Mint's silver eagles.
AL
<< <i>. . . , I do not know if it can be avoided. >>
A couple of questions I have:
0) Is it just an issue with Silver American Eagles?
1) Does it occur more often with graded coins or with coins in the mint's original packaging?
2) Does it occur across all dates or just certain dates?
3) Is this something that occurs immediately or over a period of time?
SoundPoint
<< <i>It is a phenomena that has been plaguing ASE's since the series started. I have yet to understand why an in depth study has not been performed (I have posted regarding this several times). All ASE's do not develop milk spots... there 'seems' to be some relation to storage conditions.. but this has not been proven either. Some collectors (myself included) who have multiple sets of ASE's, have NO milk spotting.. others seem to have it continuously. I am sure that an assessment by an atomic absorption unit could identify the compound(s) involved, which would lead us to a causitive chain of events. Neither the US Mint nor professionals on this forum seem to be interested enough to pursue this analytical research. Cheers, RickO >>
i think it is a problem with a "rinse" the coins go through. I haven't a clue what the process is, but, i think the reason some do and some don't develop milk spots may have to do with the quality of this final rinse (if there is one) . it must have a life span, before it needs to be freshened or replaced, similar to photo chemicals (my guess) and maybe this rinse is beyond it's lifecycle sometimes and still rinsing coins....if there is a rinse. the spots look like hardwater stains on glass. when my MR Clean car wash gadget needs to have the filter changed, the ability to reduce or eliminate spotting opn my car with a final rinse is greatly reduced.
and yes why an indepth study has not been done is on the top of my list, too.
i do not think it has to do with humidity/heat cycles on slabbed or mint capsuled coins, but it may exacerbate a situation, or delay the inevitable. i have seen milk on EverythinG ASE.
seems to happen without any pattern. some folks have the best environment for storage and still experience spotting. some don't have a problem until after having the coin slabbed. some coin collectors never have coins slabbed and still get spots. and some people buy from the mint and end up with spots.
and
Hoard the keys.
<< <i>I figured it was some factor of humidity. I live in a very arid climate (nearly a desert) and it will be interesting to see if my 2007-W slabbed ms69 develops any spots. >>
I too live in a rather arid climate, but it did not keep the SAEs from developing spots. Because it was very inconsistent, I tend to think it began at the Mint. Just the luck of the draw as to whether your SAEs were properly rinsed and may be a little more impervious to later spotting. I'm not buying anymore SAEs because of it.
My Registry Sets
That being said, I would recommend buying a cigar humidor and storing them in that...
Search the word "milk"
Regards,
Scott
<< <i>
<< <i>. . . , I do not know if it can be avoided. >>
A couple of questions I have:
0) Is it just an issue with Silver American Eagles?
1) Does it occur more often with graded coins or with coins in the mint's original packaging?
2) Does it occur across all dates or just certain dates?
3) Is this something that occurs immediately or over a period of time?
SoundPoint >>
It seems to be largely associated with the silver eagles. Some coins taken from previously unopened mint tubes have been reported to be spotted as well. I have never seen here that it was a problem with similar mint produced coins like the Buffalo dollar, the SF Old Mint commems, etc. My limited investigation indicates the the spot/s consists of chloride with or without the presence of sodium. Under high microscopic magnification it seems that the chloride accmulates on the rough areas of the coins surface. The shape of the spots [mostly round] indicates that they are probably residue left by evaporation of a liquid either from an additive in a rinse, inadequate rinse with a pure distilled/deionized water source or the the presence of a contaminant in the rinse water that the minting facility doesn't know is there. I have seen some spots that look more yellowish than white so there may be more than one problem.
Its been said that spotting can be prevented if you dip the coins in EZest BEFORE the spots are visible. Once visible on uncirc coins it is difficult or impossible to remove them without evidence that the spot was removed. I'm of the understanding that proof strike coins are easier to fix.
As for humidity or other environmental issues, I would guess that some of the ASEs are predisposed to spotting for unknown reasons related to the manufacturing process as mentioned above. Exposure to the right conditions of which humidity may be just one would promote/facilitate the reaction leading to spot formation.
Feel free to add any other evidence you may have or correct anything I may be in error about.