FMF - Friends of Minerals Forum, discussion and message board

[Roger Warin]

Hi,
About old silver specimens...
We do not discuss tastes and colors, but still.
You know that copper and especially silver corrode over time. After a few years, we get a beautiful patina, but after decades or even a century, silver crystals become black.
Is it appropriate cleaning? If so what? With ammonia or a softer complexing agent?
Roger.

[GneissWare]

I would never clean them.

[chris]

Hello Roger,

I agree with Bob. I have a silver / acanthite specimen whose silver crystals turned black over time but eventually decided to keep them this way. Might worth asking Jordi about a way to clean them.

Christophe

[Susan Robinson]

I have seen a few cleaned with diluted silver cleaner. You need to use an artist's brush to lightly apply it to areas where you you want to highlight the wires or crystals, and then stop when you have achieved the desired "cleaning effect."

[Riccardo Modanesi]

Hi to everybody!
If silver crystals or straws are not too thin, I usually use a little toothpaste brushing it with a tender artist brush. For copper, I use a diluted vinegar solution.
Greetings from Italy by Riccardo.

[Peter Van Hout]

Silvers and coppers who are over-cleaned looks so unnatural. Before they turn to dark, and to keep their great natural patina they could be sprayed with hairspray. Hairspray works like varnish but is much thinner and when done right it is almost invisible. And it does not harm metallic elements like copper or silvers and it could be very easily removed with acetone when necessary.

Peter Van Hout