I'm sure that mark wasn't there before, syndrome

[1949threepence]

So there you are reviewing your collection, as you do from time to time, when you suddenly come across an old and familiar coin which you've owned for a number of years, and notice a little mark/scratch/carbon spot on it, ponder for a second or two and then conclude that the blemish concerned was not on the coin when you first had it.

You hurriedly try and retrieve old pics, but often they're no real help as not all pre existing blemishes show up on the photo. So you're left wondering - was it you who accidentally allowed a minute droplet of saliva onto the field of the coin, to cause that carbon spot? Invisible at the time, but now look at it. Did you inadvertently catch the coin with whatever you were using to get it out of the tray recess, and leave a scratch there?

Or is it all your imagination?

Anybody else get this?       

[VickySilver]

Well, sort of, but it was my fault I guess.  I bought a truly fantastic 1926ME Penny from a Spink SNC in the year 2000. Coin listed as GEF, but in fact on delivery noted it to have booming red/orange lustre. I was a bit nervous about maintaining the surfaces in the humidity of the Washington DC area and so about 5-6 years later slabbed it - it still looked superb but after about 10 more years the lustre had given away to Red Brown surfaces.

Still the nicest I have seen but my goodness how it hurt....BTW the coin is the PCGS "plate" coin for the date if you look at their "Pop Reports" (it graded MS65RB).

[Bronze & Copper Collector]

3 hours ago, VickySilver said:

Well, sort of, but it was my fault I guess.  I bought a truly fantastic 1926ME Penny from a Spink SNC in the year 2000. Coin listed as GEF, but in fact on delivery noted it to have booming red/orange lustre. I was a bit nervous about maintaining the surfaces in the humidity of the Washington DC area and so about 5-6 years later slabbed it - it still looked superb but after about 10 more years the lustre had given away to Red Brown surfaces.

Still the nicest I have seen but my goodness how it hurt....BTW the coin is the PCGS "plate" coin for the date if you look at their "Pop Reports" (it graded MS65RB).

Magnificent coin....

[Sword]

6 hours ago, 1949threepence said:

Anybody else get this?       

I think most of us do from time to time. The problem is that a blemish might be insignificant, but you will keep looking at it after it has been spotted.l keep mine in quadrums and so I don't need to worry about new scratches etc. But l do ask questions like if lustre has subdued on one side over time or is a carbon spot or other type of spot becoming more noticeable.

[1949threepence]

7 hours ago, VickySilver said:

Well, sort of, but it was my fault I guess.  I bought a truly fantastic 1926ME Penny from a Spink SNC in the year 2000. Coin listed as GEF, but in fact on delivery noted it to have booming red/orange lustre. I was a bit nervous about maintaining the surfaces in the humidity of the Washington DC area and so about 5-6 years later slabbed it - it still looked superb but after about 10 more years the lustre had given away to Red Brown surfaces.

Still the nicest I have seen but my goodness how it hurt....BTW the coin is the PCGS "plate" coin for the date if you look at their "Pop Reports" (it graded MS65RB).

That's really disappointing. You'd also have thought that once in the slab, there would be environmental protection - unless the damage from humidity had already occurred whilst unslabbed, and just took time to appear once under the slab.

Given that the lustre would already have existed unaffected for many decades, it's telling that higher average humidity levels would tend to degrade it quite quickly than the average 40% to 60% levels in the UK. 

[blakeyboy]

Is a slab not sealed, and if it is, do they not flush the humidity out with dry air/gas when sealing it?

[1949threepence]

36 minutes ago, blakeyboy said:

Is a slab not sealed, and if it is, do they not flush the humidity out with dry air/gas when sealing it?

I'm no metallurgist, nor expert on hermetically sealed slabs, but paragraph 8(b) of this link is quite revealing:-

Quote

 

Coins made of copper, bronze and brass or are copper-plated can change over time. Accordingly, with regard to copper, bronze, brass or copper-plated Coins, the grade portion of this Guarantee will no longer apply after the 10-year anniversary of their date of encapsulation. The expiration date of the grade portion of this Guarantee can be found by entering the Coin’s certification number in the Verify NGC Certification section of the NGC website or by contacting NGC Customer Service.

 

 

[Bruce]

2 hours ago, 1949threepence said:

I'm no metallurgist, nor expert on hermetically sealed slabs, but paragraph 8(b) of this link is quite revealing:-

 

Actually, i don't know there is a 10-year benchmark for bronze/copper coins.

 

7 hours ago, Sword said:

I think most of us do from time to time. The problem is that a blemish might be insignificant, but you will keep looking at it after it has been spotted.l keep mine in quadrums and so I don't need to worry about new scratches etc. But l do ask questions like if lustre has subdued on one side over time or is a carbon spot or other type of spot becoming more noticeable.

Me too, once you notice any impecfection, you will always look at it😅.

[1949threepence]

6 hours ago, Bruce said:

Actually, i don't know there is a 10-year benchmark for bronze/copper coins.

 

I knew there was a 10 year "guarantee" but I'd no idea it only applied to the metals referred to.  

[Sword]

2 minutes ago, 1949threepence said:

I knew there was a 10 year "guarantee" but I'd no idea it only applied to the metals referred to.  

I think that is due to copper coins being more reactive than silver and is more susceptible to the effect of moisture and gases in the atmosphere. Hence copper is more likely to change even after slabbing.

[Sword]

18 hours ago, VickySilver said:

Well, sort of, but it was my fault I guess.  I bought a truly fantastic 1926ME Penny from a Spink SNC in the year 2000. Coin listed as GEF, but in fact on delivery noted it to have booming red/orange lustre. I was a bit nervous about maintaining the surfaces in the humidity of the Washington DC area and so about 5-6 years later slabbed it - it still looked superb but after about 10 more years the lustre had given away to Red Brown surfaces.

Still the nicest I have seen but my goodness how it hurt....BTW the coin is the PCGS "plate" coin for the date if you look at their "Pop Reports" (it graded MS65RB).

You really can't blame yourself for that. Slabbing a coin would generally decrease the possibility of the surface of copper / bronze toning. But there is always a chance that it won't. However, there is no guarantee that your coin would be any better off if you didn't slab it.  At least it wasn't something like verd developing due to sealed in moisture.

I wonder if anyone has ever used Lighthouse Quadrum Intercept Coin Capsule . The blur states that "The insert has been modified to neutralise harmful atmospheric substances inside the capsule, so that your coins are stored in a non-corrosive microclimate.

The advantages of the QUADRUM Intercept coin capsule:

Active protection from tarnishing for up to 15 years"

Of course "up to" is not particularly comforting.

Might be worth a try for copper / bronze?

[VickySilver]

I probably should have. Too late now, I think the toning has stabilized (hope)....