Back to Ganoksin | FAQ | Contact

Copper stain on sterling silver


#1

I have been cleaning a students sterling silver chain maille
bracelet which was left in a commercial jewellery cleaning fluid
while she went on holiday, the solution dried out and the jewellery
became coated with a thick black and rust coloured deposit. In the
cleaning fluid was a mixture of jewellery, gold, sterling and

Tumbling has removed all of this deposit, some of the chain is now
it’s original sparkling silver, but some of the chain has patches of
a light copper colour as though it has been very unevenly copper
plated. Some rings in the chain are now both silver and copper!!!

Why and how has this copper stain appeared on the sterling silver
and is it possible to remove it.

Val S-S
ValleyGem


#2

It could be an electrolytic plating from the solution in which the
bracelet was placed. It could be cuprous oxide (fire scale). It could
be that the bracelet is silver plated over copper.

My best advice is to first use a test kit to determine if the
bracelet is silver, and then to let us know what you have found out.

Good luck.
Michael Rogers


#3

Hello,

the copper plating can be a result from teh stainless steel spring
inside the clasps wich are connected to your golden en silver chains.

Nitric acid will take this of but take care about healt and safety
rules and ask for MSDS!!

As far as I can reacall, someone mentioned something about adding
some H2O2 to your picle in order the activate this solution. Can’t
remember the details but you’ll find on ganoksin.

Regards -))


#4

Add some hydrogen peroxide to some of the regular pickle. Watch
closely. It makes a strong pickling solution. It should remove the
pink copper plating. Afterwards, it can be put back with the rest of
the pickle.

marilyn


#5

Thank you Marilyn, yes, that would have worked.

I have been able to remove the copper from the sterling silver
bracelet, the response from Pedro Alonso-Sanchez caused me to look at
the problem differently, and instead of using pickle with an additive
I made up a simple acid mixture of lemon juice and salt, I did this
because of my sensitivity to chemicals. One hour in this mixture
removed the copper, then a couple of hours in the vibratory tumbler
with stainless steel shot renewed the polish.

Cheers, Valma Spencer-Sun.