Black spots on uncirculated 2011 2p

[Lotad]

I've been collecting uncirculated 2p's, mainly from buying sealed bags of 50. Quite often there are blemishes or spots on varying amounts of the coins, but these 2011 were riddled with them.

What are these spots? Some even have black spots which are raised from the service and look like mould.

The first two photos are of the 'best' coin of the bag, the others are indicative of the rest.

Is there anything I can do to prevent it from getting worse, or even remove the spots?

[Lotad]

[Lotad]

[JLS]

Looks like corrosion from exposure to water or moisture to me. On worn coins there are often good (albeit time consuming) ways to remedy this sort of damage, but on anything uncirculated with original lustre, you would end up with a toned coin at best. 

Really nice decimal coins ex-circulation (as opposed to out of mint sets) can be quite hard to find. 0

[Lotad]

Thanks JLS, so improper storage might be at fault then. Are coins like these containing copper more prone to this sort of thing? So far the oldest bag of uncirculated 2p has been 1987, and from memory they were all fine.

I've also found some 2p with red spots rather than these kind. I'll see if I can get a photo.

[Lotad]

[Rob]

I'd go for water damage too.

Interesting that you collect 2ps. Based on the numbers I have sold over time, these are probably the least collected circulating decimal denomination. Why? They are the largest 'coppers' and size usually means more popular, though it's also fair to say that everything is dwarfed by 50ps and £2s which are the only decimals that have really caught the public imagination.

[mick1271]

3 hours ago, Lotad said:

Thanks JLS, so improper storage might be at fault then. Are coins like these containing copper more prone to this sort of thing? So far the oldest bag of uncirculated 2p has been 1987, and from memory they were all fine.

I've also found some 2p with red spots rather than these kind. I'll see if I can get a photo.

1987 2ps are bronze , but since 1992 ,they have been copper plated steel .This would probably make a difference in the colour of the corrosion (spots) . 

[Lotad]

On 10/14/2020 at 4:03 PM, Rob said:

Interesting that you collect 2ps. Based on the numbers I have sold over time, these are probably the least collected circulating decimal denomination. 

I can't think of a specific reason why I decided upon 2p's, probably because of their size and colour, and similarity to the predecimal penny. I think they're just a nice humble coin. I also collect £2 in a similar fashion, and I think the reason for those is simpler. I remember when the current bimetallic was introduced, me and my mum would hoard them in a piggybank.

[Sword]

On 10/14/2020 at 4:03 PM, Rob said:

... though it's also fair to say that everything is dwarfed by 50ps and £2s which are the only decimals that have really caught the public imagination.

I think people are keener to collect 50p and £2 coins due to the seer number of reverse designs available making the series more "interesting". By contrast, are just two reverse designs for 2ps.