super light chain going black in pickle

[lilyandloulou1]

Please help as this is driving me mad! I need to pickle pendants which need a good fifteen minutes in my citric acid pickle, but they are attached to very light silver chain which turns black when left in the pickle this long.
How can I stop this happening and how can I now sort the chain which has gone a horrible black? It's too fine to heat as it immediately melts and too fine to brush with steel wool to get its silver colour back.

Any help would be hugely appreciated, thank you!

[Dennis]

1. It is much more convenient to pickle your pendants and finish them first, before attaching them to a chain.

2. Use a hand hot solution of alum as a pickle and it will be ready in two to three minutes. Alum is safe and is in fact used in some Indian recipes. You can buy it on line, or at some Indian grocers.
It will not discolour chains, provided you use brass or plastic tweezers. do not use steel.

You will probably be able to revive your blackened chain in this, or if not, then in Goddards Silver Dip. Dennis.

[CJ57]

Alum powder used to be rally difficult to come by, my chemist couldn’t even find it in his book which I found strange.
On amazon it’s listed as a foodstuff mainly and I wouldn’t really go past it.

[ps_bond]

Can I just remind people that while alum (the traditional name - potassium aluminium sulphate, or sulfate for the US market - might garner additional hits) and citric acid are low toxicity (according to LD50 tests), the moment you use them as pickle you dissolve copper into it, which is not low toxicity.

[CJ57]

So what would you suggest Peter and how toxic are we speaking?

[ps_bond]

It's more the cavalier attitude to disposal I've seen elsewhere - "it's natural!" "it's safe!"... In terms of human toxicity, don't drink it/gargle it/bathe in it/stick your hands in the solution (also hurts like hell if you have any cuts). In terms of marine wildlife toxicity, don't pour it down the drain. Copper sulphate is used as a stump killer (although I prefer potassium nitrate, it's more... Fun); it's also the main ingredient in Bordeaux solution (not good for moulds either). Neither are ideal as they get into the water table - they aren't magically filtered by the soil, per one claim I saw.

Water is safe. Water that I've dissolved potassium cyanide in, not so much. Both are natural though.