Dug some 40 kilogrammes of British coin out from the abyss where they were hidden: The coins date from William III halfpennies on up to 1967 QEII coins - lots of Australian, Irish and South African thrown in. There are sterling silver coins, .500 coins, almost 1000 tanners, 1500+ halfpennies, several thousand pennies, hundreds of sterling threepence etc. I literally bought up lots of these for a couple of years and just bagged them and forgot about them.
I've read keeping different metals together can cause damage. Like keeping silver next to copper. Not sure if there's any truth to that or not.
It's certainly possible in principle, especially if they get damp. That would tend to make the copper corrode away, while protecting the silver -- but "protecting" here just means "slowing down its oxidation/corrosion", and no guarantees that it wouldn't make unsightly spots. In the same way, zinc protects copper or iron if they're in contact. So the zinc coating on steel cents tended to protect the steel core, while the zinc filling in modern cents tends to dissolve away if there's a nick in the copper coating, leaving a deep pit. That's one of the main reasons that copper-coated zinc coins are a stupid idea.
The most striking example of this occurs with the Tin Farthings and Halfpennies issued in Britain in the 1680s and 1690s. They soon discovered that left as pure Tin they corroded very quickly, but with a Copper plug in the centre, the electrolytic effect made them last a lot longer. They are still very scarce as they also disintegrate in extreme cold, so the main source of good examples now is underwater. Oh and by the way, I had a similar hoard to the above (without the Silver) until recently. I sold it en masse to a friend who is handing it over to his Grandson in a Treasure Chest!
The sort is half way finished, all the copper/bronze are together in one big jug, all the copper nickel in another and there is that little mountain of sterling and .500 silver that teases even me - silver have done rather well since I bought those in job lots years ago. Quite a few colonial coins, even found a 1/2 anna from India, lots and lots of Australian, South African, New Zealand, Ireland etc. I think the Ozzie coins are .750 fine - they were a mixed of silver on up to the end of predecimal. Seen some neat dates like in pennies 1951, 1953 etc that are right uncommon.
They only made 120k 1951 pennies, the 1953 is more common with a mintage over 1 mil. The rare pennies from 1900 on: 1933 (7 Known). Any found will most likely be fake. 1950 240k minted. 1951 120k minted. 1953 1.3m minted. The 1831, 34, and 37 pennies had less than 1m minted. The 1837 had 175k minted. I own a 1831 penny. They only minted 836,00 of them.
Good hair day picture: "I woke up in a Soho doorway a policeman knew my name. He said you can sleep at home tonight if you can get up and walk away..." evil: Who are you? The Who
A few pounds, still have to sort out all the sterling and .500 stuff. Found several sterling florins and halfcrowns though.
1950 240k minted. For the Caribbean territories 1951 120k minted. For the Caribbean territories 1953 1.3m minted. Mostly for sets, keepsakes in Britain - weren't regularly circulated. There were so many pennies struck from 1936 - 45 that Britain really didn't need to strike a lot of them - there was a glut of them.
Only less than three dozen farthings from the 1820s on up to the early 50s when they stopped making them. Never found them in quantities - they disappeared from circulation prior to decimalisation.
