What causes "milk spots"?

I just took out my silver collection to take a look at the silica gel
canisters and I noticed that my 1996 SAE has what I believe in numismatics
is referred to as "milk spots". Now what causes them? All of my silver
bullion coins are stored in a Tupperware type container which is safe for
coins and there are several silica gel canisters in with them. They are
checked regularly. The coins are all in air-tites. The area they are
stored in has no moisture. The area is just above my garage, which is cold,
but that shouldn't matter. Any ideas? It makes me mad to think that I
spent all this money on coins that I enjoy that are going to not be worth
anything above melt if they keep on getting these spots. Thanks.

Mark

The usual cause for milk spots is resdue from the cleaning process during the
minting of the coin and has nothing to do with the current storage media.

Alan Herbert
The AnswerMan

On 28 Apr 2004 13:05:32 GMT, (AnswerMan2) is alleged to have
written:

The usual cause for milk spots is resdue from the cleaning process during the
minting of the coin and has nothing to do with the current storage media.

Alan Herbert
The AnswerMan

At what point in the process are the coins washed? After striking, before
upsetting or?

Bruce

Two thoughts:

First, even though you say there is "no moisture," there IS moisture. I
don't think there are any areas on the planet, including Death Valley, where
the relative humidity is zero. There are stories of people surviving there
by making a sun still to capture moisture coming up from the ground.

Second, it wasn't clear if just the garage is cold, or if the area above it
is cold. If the coins DO go through alternations of cold and hot, at least
some of the available moisture may condense on the coins during the cycle,
even with silica gel in the vicinity. The most dangerous part of that cycle
is the period of time when the coins are still cold, but the ambient air is
warming, picking up greater relative (and absolute) humidity that can be
delivered to the coin storage area.

"MarkR" wrote in message
.. .
I just took out my silver collection to take a look at the silica gel
canisters and I noticed that my 1996 SAE has what I believe in numismatics
is referred to as "milk spots". Now what causes them? All of my silver
bullion coins are stored in a Tupperware type container which is safe for
coins and there are several silica gel canisters in with them. They are
checked regularly. The coins are all in air-tites. The area they are
stored in has no moisture. The area is just above my garage, which is
cold,
but that shouldn't matter. Any ideas? It makes me mad to think that I
spent all this money on coins that I enjoy that are going to not be worth
anything above melt if they keep on getting these spots. Thanks.

Mark

Bruce Hickmott wrote:

On 28 Apr 2004 13:05:32 GMT, (AnswerMan2) is alleged to have
written:

The usual cause for milk spots is resdue from the cleaning process during the
minting of the coin and has nothing to do with the current storage media.

Alan Herbert
The AnswerMan

At what point in the process are the coins washed? After striking, before
upsetting or?

Bruce

I've also heard that some of those "milk spots" are from people
talking over the coins and expelling spittle which settles on the coin
and causes the white spots. Could be an urban legend but I do
remember, from my time working in a coin shop, that many times a raw
coin is sitting on a felt pad while people talk about it. So.....
Cliff

p.s. Plus, could be the allergy season at the mint with everyone
sneezing over the coins

AnswerMan2 wrote:
The usual cause for milk spots is resdue from the cleaning process during the
minting of the coin and has nothing to do with the current storage media.

Alan Herbert
The AnswerMan

That's what I thought. Wasn't the spotting on some golden dollars due
to that?
I think that's why some coins that have beed dipped without a thorough
wash afterwards sometimes end up with a splotchy kind of toning.
Jack

Subject: What causes "milk spots"?
From: Cliff
Date: 4/28/04 9:10 AM Central Daylight Time
Message-id:

Bruce Hickmott wrote:

On 28 Apr 2004 13:05:32 GMT, (AnswerMan2) is alleged to
have
written:

The usual cause for milk spots is resdue from the cleaning process during
the
minting of the coin and has nothing to do with the current storage media.

Alan Herbert
The AnswerMan

At what point in the process are the coins washed? After striking, before
upsetting or?

Bruce

I've also heard that some of those "milk spots" are from people
talking over the coins and expelling spittle which settles on the coin
and causes the white spots. Could be an urban legend but I do
remember, from my time working in a coin shop, that many times a raw
coin is sitting on a felt pad while people talk about it. So.....
Cliff

p.s. Plus, could be the allergy season at the mint with everyone
sneezing over the coins

I was under the impression this is what caused carbon spots on the coins.
The white spots are fairly common on SAE's and I think it's more likely
something in the processing.
All the best, Pete

"MarkR" wrote in message
.. .
I just took out my silver collection to take a look at the silica gel
canisters and I noticed that my 1996 SAE has what I believe in numismatics
is referred to as "milk spots". Now what causes them? All of my silver
bullion coins are stored in a Tupperware type container which is safe for
coins and there are several silica gel canisters in with them. They are
checked regularly. The coins are all in air-tites. The area they are
stored in has no moisture. The area is just above my garage, which is
cold,
but that shouldn't matter. Any ideas? It makes me mad to think that I
spent all this money on coins that I enjoy that are going to not be worth
anything above melt if they keep on getting these spots. Thanks.

Mark



So should I just not worry about it or should I go out and buy a new coin
for every one that has the spots on them? Advice please. Thanks again.

Mark

At what point in the process are the coins washed? After striking, before
upsetting or?
The planchets are washed after they are annealed.
Every mint (U.S. and European) that I have visited seems to have a different
formula for cleaning planchets, mostly based on a detergent, but often with
other chemicals mixed in.
Alan Herbert

On 30 Apr 2004 14:42:53 GMT, (AnswerMan2) is alleged to have
written:

At what point in the process are the coins washed? After striking, before
upsetting or?
The planchets are washed after they are annealed.
Every mint (U.S. and European) that I have visited seems to have a different
formula for cleaning planchets, mostly based on a detergent, but often with
other chemicals mixed in.
Alan Herbert


Thanks Alan. Is there any country you're aware of that does not get these milk
spots with their cleaning formula?

Bruce