Milk Spots on Silver Coins

[Dan12345]

I received a coin from the royal mint this week that has a few milk spots. Coin was a 1986 us silver dollar. Would you guys send it back and ask for a replacement?

[Chorlton]

Best to check first if this is common for the coin in question. Then you can either decide to live with it or send it back. Generally older silver coins slowly tone over time and don’t have this problem but I will vary from coin to coin. The modern RM silver proofs in my experience have issues with milk spots and very rapid toning, which is why I only look at much older silver coins now as they will have stabilised and any issues would be apparent by now. For bullion it is different but there is an element of good condition coins being easier to sell with a potentially better premium.

[MonkeysUncle]

21 hours ago, KevinFlynn said:

I'm learning to leave my tubes sealed 😯

What is the trust value on originally sealed tubes in private to private trade?

I talked to a professional seller and they said they would open the seal to make sure the content is what it says it is (kind of defeats the idea of the seal, but who knows).

 

Given the quality of fake items that come from China these days (as opposed to a lot of poor quality fakes elsewhere), I would always open a seal. I really don't think forging a holographic shiny sticker strip would be much of a challenge to the right man - knocking out a forged coin I imagine is harder.

[stefffana]

In my opinion, the milky spots are not a real problem. These are coming naturally, like tarnish or patina, doesn't matter if the coin is protected or not. It is a natural reaction between silver and chemical particles from air. Even the coin is sealed and protected in capsule, this process can not be avoided, can be only slowed down.

Why are coming more often now? Because the chemical composition of atmosphere has changed drastically in the last 10 -20 years. I am not a a big fan of conspiracy theories, but nobody knows what is spreading every day in atmosphere by jets and airplanes.😁

Why the older coins are not affected so much? Because these coins built already a very thin layer of sulphur patina and the new chemicals from air are not penetrating to silver surface.

Of course, who want a perfect shiny coin, can choose between expensive gold and cheap stainless steel. Personally, I do prefer silver, even with tarnished rims or milky spots.

Cheers!

Stefan.

 

[sovereignsteve]

Thought I remembered this in the deep recesses of my mind. Finally found it!😊

 

[sovereignsteve]

Did you delve any deeper T?  @UraaniBarbaari

[slywolf]

On 18/08/2021 at 18:58, LawrenceChard said:

I had never heard the term "milk spot" until the last year or two.

I think I first became aware of it on TSF, where there seem be be lots of discussions and complaints about milk spots, mainly about British Royal Mint silver coins including some high premium proof coins, and also bullion coins like Britannias.

This composite images shows milk spotting on a 2021 UK silver proof Queens's Beasts Black Bull of Clarence coin, one of 9 coins from a 10 coin Royal Mint set to feature this production defect.

Of course, I have seen white spots on silver coins before, but had never called them milk spots, or heard anyone else call them that, until quite recently as I just mentioned.

I can call to mind seeing a slight grey blue bloom on some silver proof crowns from 1980 and 1981. In the past, we have tried silver dipping a few coins, but with very poor results. I suspect that this bloom is caused by the same or a similar production problem.

A quick search using Google will find many pages discussing the problem, but none which states its cause, although a few of the sites including YouTube videos seem to claim to explain the phenomenon and its cause, but fail to actually do so.

A number of these sites mention that it might be caused by solvents or detergents used to clean the planchets (blanks). Some suggest PVC. Although PVC can and does cause some tarnishing, corrosion, or discoloration, I have never noticed it causing milk spots, so I think we can discount the PVC theory. My own thoughts were that it might be caused by oils or other lubricants, affecting either the blanks or the actual coins during the striking process.

The Royal Canadian Mint is to be commended because, according to its website, it carried out research over about 4 years, and in 2018 introduced something called MintShield, which reduces , slows down, or helps to prevent milk spotting. It proudly states that it now incorporates MintShield into its silver bullion maples, and other silver coins. However...

... Disappointingly, the RCM fails to state clearly what causes the problem, what MintShield is or how exactly it works, stating it is a secret process. While I can understand it protecting its investment in research to develop the process, I feel I should deduct points for choosing to withhold the basic facts, namely what is milk spotting, and what causes it.

As recently as yesterday, I asked our main Perth Mint contact what Perth Mint knew, as I cannot remember seeing it on their silver coins, although I feel sure somebody will have done.

I received the following very prompt reply:

Such spots are caused regularly by some small pollutions at the production process. TPM has made large efforts by cleaning the factory to prevent such spots.

I will check if there is any further “official” statement available about that theme from TPM.

Obviously, this does not explain everything we all want to know, but at least it is more than I have heard from any other mint, apart from the RCM as mentioned above. If I receive any further information, I will post it here.

 

 

 

hi i am ronnie newby on here, i have coins from royal mint with these milk spots, so are these milk spots a problem with bullion 999% coins or with other lower silver content coins for i have only seen these marking on the bullion coins.

[LawrenceChard]

4 hours ago, slywolf said:

hi i am ronnie newby on here, i have coins from royal mint with these milk spots, so are these milk spots a problem with bullion 999% coins or with other lower silver content coins for i have only seen these marking on the bullion coins.

The photos on my post you quoted are of British Royal Mint silver coins including some high premium proof coins, namely Queen's Beasts.

So, not only 999, not only bullion.

For a definitive answer you should probably ask the Royall Mint, but don't expect to get a fully detailed or satisfactory explanation.

[Bruce06]

17 hours ago, Dan12345 said:

I received a coin from the royal mint this week that has a few milk spots. Coin was a 1986 us silver dollar. Would you guys send it back and ask for a replacement?

Buying old coins from RM is with a problem that no exact coin picture is provided, all are rough guess based on their grading (sometimes quite inaccurate).  If the price is only few pounds, i think it's fine.  However if it costs over 20 or something, i will try to request for more details.  I remember i asked for additional pictures for a particular item before, but they decline to do so and said if you are not satisfied after receiving it, you can return it😫.

For your case, if you are not satisfied with it, contact RM and return it. 

By the way, what kind of US silver dollar you are looking for?  Maybe forum members can help you to have it.

Edited August 22, 2021 by Bruce06

[KevjustKev]

On 20/08/2021 at 12:01, Arcadian said:

A quick Google suggests it's caused by leftover traces of borax, used in the manufacturing process.  I don't know if this is true, but it might explain the random nature of spotting.

I'm not so sure, well for Royal Mint anyway. Borax is banned in the UK and the EU, it has been linked to liver disease.

Edited August 26, 2021 by tallthinkev

[Arganto]

On 21/08/2021 at 17:33, sovereignsteve said:

Thought I remembered this in the deep recesses of my mind. Finally found it!😊

 

What an interesting thread that got started there, the most illuminating on the subject that I've read so far. It's a shame it didn't continue, but such is the fickle nature of internet forums! 

[Bimetallic]

On 21/08/2021 at 15:05, LawrenceChard said:

The photos on my post you quoted are of British Royal Mint silver coins including some high premium proof coins, namely Queen's Beasts.

So, not only 999, not only bullion.

For a definitive answer you should probably ask the Royall Mint, but don't expect to get a fully detailed or satisfactory explanation.

@LawrenceChard When you say "not only 999", contrasting this with Queen's Beasts, what's the difference? Are you meaning to contrast 999 with 9999? Queen's Beasts are 9999, but I wouldn't have thought this mattered for milk spots.

By the way, did the Royal Mint remove the fineness from the Queen's Beasts design? Your image is missing the fineness. I've attached the version of the Black Bull of Clarence that I've seen.

 

[zxtm99]

30 minutes ago, Bimetallic said:

@LawrenceChard When you say "not only 999", contrasting this with Queen's Beasts, what's the difference? Are you meaning to contrast 999 with 9999? Queen's Beasts are 9999, but I wouldn't have thought this mattered for milk spots.

For a QB, if the milk spot weighed more than 6 mg, it wouldn't be 999.9.....🤨

[LawrenceChard]

On 21/08/2021 at 23:05, LawrenceChard said:

The photos on my post you quoted are of British Royal Mint silver coins including some high premium proof coins, namely Queen's Beasts.

So, not only 999, not only bullion.

For a definitive answer you should probably ask the Royall Mint, but don't expect to get a fully detailed or satisfactory explanation.

 

31 minutes ago, Bimetallic said:

@LawrenceChard When you say "not only 999", contrasting this with Queen's Beasts, what's the difference? Are you meaning to contrast 999 with 9999? Queen's Beasts are 9999, but I wouldn't have thought this mattered for milk spots.

By the way, did the Royal Mint remove the fineness from the Queen's Beasts design? Your image is missing the fineness. I've attached the version of the Black Bull of Clarence that I've seen.

 

 

On 21/08/2021 at 18:32, slywolf said:

hi i am ronnie newby on here, i have coins from royal mint with these milk spots, so are these milk spots a problem with bullion 999% coins or with other lower silver content coins for i have only seen these marking on the bullion coins.

 

On 21/08/2021 at 23:05, LawrenceChard said:

The photos on my post you quoted are of British Royal Mint silver coins including some high premium proof coins, namely Queen's Beasts.

So, not only 999, not only bullion.

For a definitive answer you should probably ask the Royall Mint, but don't expect to get a fully detailed or satisfactory explanation.

 

33 minutes ago, Bimetallic said:

@LawrenceChard When you say "not only 999", contrasting this with Queen's Beasts, what's the difference? Are you meaning to contrast 999 with 9999? Queen's Beasts are 9999, but I wouldn't have thought this mattered for milk spots.

By the way, did the Royal Mint remove the fineness from the Queen's Beasts design? Your image is missing the fineness. I've attached the version of the Black Bull of Clarence that I've seen.

 

As you can see, I was quoting @slywolf, which is why I referred to 999, although it was unusual for me not to notice and comment in his "999%" which could probably only be achieved if silver had a specific gravity of 105, instead of 10.5! Of course, I feel sure he meant 999 ppt.

You are quite right when you point out that the silver QB range are 9999 silver (99.99% or 999.9 ppt) and also that it makes no difference as far as milk spot are concerned, and of course the actual difference is only 1 part per 10,000 but it makes a (slightly anodyne) unique selling point.

Before you mentioned it, I had not noticed the omission of the fineness, but it looks like the RM only did this on the proof version(s), for some obscure reason, which will possibly never be explained. The RM's own website states these are 999, as does ours:

Specification

Diameter	38.61mm
Weight	31.21g
Alloy	0.999
Obverse Designer	Jody Clark
Reverse Designer	Jody Clark
Mint	Royal Mint
Mintage	6,000
Finish	Silver Proof

It is also possible that the proofs were also made using 9999 silver, but that someone at the RM forgot or failed to notice. You could try asking them, and see what sort of answer you get!

If you do get an answer, please post it here, I guess a number of TSF members will be interested, and possibly amused or bemused. 

 

[kimchi]

On 19/08/2021 at 08:29, TeaTime said:

I've had Perth Mint coins that show milk spotting well over a year after purchase. I would expect milk spots (if being caused purely by contaminants) to show pretty much immediately (refer to the recent Queens Beasts proof sets debacle), not 12 months later. The only conclussion i can come to is that atmospheric conditions are also a part of the problem with milk spotting.

In my experience, adverse atmospheric conditions (including how airtight the capsule is) just bring it out faster.

On 20/08/2021 at 13:08, LawrenceChard said:

It is unlikely that fine silver would be worse affected than lower finenesses such as 925 or 500.

It is probably that many modern silver bullion, collector, and proof coins are made using 999 silver, which buyers expect to be perfect, so they get scrutinised more than older circulation coins.

Also anecdotal, but in all my time here on the forum I have not seen a single milk-spotted 925 coin (including, of course, from the Royal Mint, who produce plenty).

Edited September 2, 2021 by kimchi

[kimchi]

On 21/08/2021 at 23:05, LawrenceChard said:

For a definitive answer you should probably ask the Royall Mint, but don't expect to get a fully detailed or satisfactory explanation.

I think you'd have more joy asking Hannibal Lector what kind of 'sweetmeats' he's just served you for dinner!

[Arganto]

12 minutes ago, kimchi said:

In my experience, adverse atmospheric conditions (including how airtight the capsule is) just bring it out faster.

Also anecdotal, but in all my time here on the forum I have not seen a single milk-spotted 925 coin (including of course the Royal Mint, who produce plenty).

This is a good point. I've seen/had plenty of tarnished/toned .925 coins/medals but don't recall ever seeing THE MILK on them. I also don't ever recall seeing anything like that on circulating coins either, which I believe was brought up by someone.

I have had .999 commemorative medals that had atrocious MILK on them. These were made ~early/mid nineties for reference.

[kimchi]

28 minutes ago, Liam84 said:

This is a good point. I've seen/had plenty of tarnished/toned .925 coins/medals but don't recall ever seeing THE MILK on them.

Tarnished and toned perhaps implies older items (?). I've never seen milk spots on fairly recent 925 Royal Mint coins, such as the King Canute.

Edited September 2, 2021 by kimchi

[LawrenceChard]

1 hour ago, kimchi said:

I think you'd have more joy asking Hannibal Lector what kind of 'sweetmeats' he's just served you for dinner!

Did you mean "sweetbreads"? 😎

[Arganto]

54 minutes ago, kimchi said:

Tarnished and toned perhaps implies older items (?). I've never seen milk spots on fairly recent 925 Royal Mint coins, such as the King Canute.

Definitely, don't think I've ever bought anything in Sterling younger than a few decades.

[kimchi]

10 minutes ago, LawrenceChard said:

Did you mean "sweetbreads"? 😎

I'm not sure what I meant, I suddenly seem to have brain spots...there is a chap who says he's from the Royal Mint here just cooking me dinner (very kind of them indeed, I didn't realise you get that kind of service for sending back a proof - I was only expecting a refund!)...

He appears to be waving around a meat cleaver and what also appears to be a scalp and the top of a skull....very strange...but - yum! - whatever he is cooking smells delicious!!

Edited September 2, 2021 by kimchi

[LawrenceChard]

17 minutes ago, kimchi said:

I'm not sure what I meant, I suddenly seem to have brain spots...there is a chap who says he's from the Royal Mint here just cooking me dinner (very kind of them indeed, I didn't realise you get that kind of service for sending back a proof - I was only expecting a refund!)...

He appears to be waving around a meat cleaver and what also appears to be a scalp and the top of a skull....very strange...but - yum! - whatever he is cooking smells delicious!!

Perhaps he thinks you wanted tickets for the Royal Mint's "Annual Lecture"

😎

[TeaTime]

I have 50+ silver proof coins (.925), not one is showing milk spots. Some have hazing to the surface which i put down to toning - but no defined 'splashes'. Similarly i have never seen the dreaded spots on a .958 Britannia.....  Would be interesting to pin down what year these spots started becoming so prevalent/noticeable..

It could also be something as simple as greater striking forces being used on certain coins (as per the thread Close up view and chemistry of the milk spots)

I do though, have a .925 RM silver medal minted in 2011 that has milk spots so it's not a new thing. Maybe it's just more common now.

[Widsith]

From the images it is interesting that the milk sports are round in nature and in the images they have a 'seed'. That they are round reminds me of 2 things: 1. Surface tension of a liquid. 2. The moisture you get surrounding a stone on the floor on a frosty day. 

It feels like some kind of liquid residue.  Liquids often contain 'solids'. Indeed, you really can buy dehydrated sea water in pots. Just add water.  So it might be the total solids of whatever was in the liquid.  That a rubber can remove them is significant.  I might see if I can get some off and put it in an x-ray defractometer at work when it opens up. Knowing the composition might help.

In summary: only 'feels' at the moment.

W

 

[Widsith]

Also if someone has acces to an ICP spectrometer that might work as well.