30-year-old mint set toning question...

[WaxonWaxov]

Hi guys,

 

Well I just dug out some mint sets I bought when I was a kid. I have a 1975/76, two 1970s, a 1972, and... a couple more.

 

Anyhow, since these things have been in their mint packaging for 30+ years, they have taken on some toning.

 

The strangest is that in one set, the high points on some of the coins have not toned. For example, Kennedy's cheek bone is as shiny as the day it was minted, but the rest of his face has aquaired the classic copper-nickel clad dullness that we are all framilliar with.

 

I figure this is because these mint sets were stacked in storage for ages and the shiny parts are where the coin was in contact with the plastic of the mint packaging. So therefore, those areas did not tone because they were not exposed to air (as I learned twenty years too late that mint set plastic is not air tight)

 

Do you think this uneven toning detracts from the coins?

 

I know, I know, I need to post pics. I will try to tomorrow. I'm afraid the effect of this toning will be difficult to capture, though.

[WinstonWare]

So it's just brownish toning? I think the valuable mint set toning is generally blue, blue-steel, or even purple. That said, yes pictures would help.

[WaxonWaxov]

maybe "toning" is the wrong word.

 

I'm not talking about color here. I'm talking about the difference in color of a brand-new circulated quarter and one that's been bouncing around for a few years... you know, "not shiny"

 

I will take pics tomorrow.

[coinman1794]

Mint set coins, just like all modern coinage from business strikes to mint sets, are coated in grease from the dies. If you buy a brand new roll of nickles from the mint (for example), and you open it and go through them, it will look like you have been reading the newspaper because your fingers will be black. This grease turns the coin yellow and then grey and then brown, etc, over time. This is why so many older mint set coins look this way...because the grease that coates the surfaces has changed color over time. This is also why so many state quarters that were certified blast white have turned yellow or brown or grey, etc. This usually does not harm the surfaces of the coin, but coins without such discoloration almost always grade higher. It can be removed, but that would require breaking the mint sets.

[cladking]

Mint set coins, just like all modern coinage from business strikes to mint sets, are coated in grease from the dies. If you buy a brand new roll of nickles from the mint (for example), and you open it and go through them, it will look like you have been reading the newspaper because your fingers will be black. This grease turns the coin yellow and then grey and then brown, etc, over time. This is why so many older mint set coins look this way...because the grease that coates the surfaces has changed color over time. This is also why so many state quarters that were certified blast white have turned yellow or brown or grey, etc. This usually does not harm the surfaces of the coin, but coins without such discoloration almost always grade higher. It can be removed, but that would require breaking the mint sets.

 

 

I'm not sure how true this is. There's no question that lubricants are used to fascilitate the coining process and that coins made for circulation are not washed after coining but I suspect your fingers would turn black anyway because of the metal. All uncirculated coins I've handled have done this. Circulated coins will as well but this is probably mostly dirt.

 

Mint set coins are washed and dried before being sealed between the four pieces of plastic. The inner plastic that is in contact with the coin is quite soft and probably contains PVC. Many of the older mint set coins have been destroyed by this media. All 1968-P cents in mint sets have carbon spots and 95% are very badly damaged. Newer mint set packaging (post-'84) is probably just two ply with no PVC.

[WaxonWaxov]

So I guess the question remains: should I remove these coins from the Mint plastic bag thingies? Perhaps slab them?

[coinman1794]

There is no question that modern business strike coins are covered with grease and dirt from the mint and probably also the machines that they go through in counting, etc. If you have ever used a solvent on a brand new quarter straight out of a mint roll/bag etc, for example, then you will see this first hand. You will see that they are loaded with black grease, no question. There are usually also a great deal of metalic dust particles. I do not know when (how far back) coins started getting this dirty during minting, but I do suspect it goes at least as far as the early 70's. However, I think today's coins are much dirtier.

 

What you do with the coins just depends on what you intend to do with the coins afterwards (keep/sell, etc), and the condition of the coins. They may not be worth certification. They may be worth more in their complete, unbroken sets. It all depends.

[WinstonWare]

I vote to leave them in their plastic bags - at least for now. In their plastic bags no one will question whether they are problem free coins or not. If you get them graded and they grade 63, 64, or 65 you haven't increased their value - you've only spent money on getting them graded. If and when you become a skilled grader, and if at that time you spot one that would grade higher than 65 it may be worth getting them graded. For now leave them there. JMHO.

[coinman1794]

I agree with you. That's probably your best bet.