Depletion guilding question

Hello Forum members; Here’s a question for some of you with some
background in chemistry. I restore a lot of estate jewelry. It’s
often difficult to “match” the color of the gold allows involved in
the articles, and some are bombed or plated too. I sometimes use
depletion gilding to bring up a little change in color, especially
when an article changes color after soldering. I can use plating,
but I’d like to deplete and burnish when possible. My question is
this. Which acids or etchants attack copper more vigorously than
they react with silver, and which etchants/acids work more on silver
as opposed to copper? I have an art nouveau piece I’m working on
where the missing part of the Griffin’s wing appears to have either
been plated green or depleted to a very green shade, as the
underlying metal is a much rosier alloy. Any help would be
appreciated.

David L. Huffman

    Which acids or etchants attack copper more vigorously than they
react with silver, and which etchants/acids work more on silver as
opposed to copper? 

Ferric chloride etches copper and copper-based metals, but not
silver. Ferric nitrate etches silver, but not copper.

David, I too restore Antique and Estate jewelry. And, I too have run
into the same problem many times. I have used many of the same
processes, depletion, plating, etc… but in many cases the results
are good but not perfect. Although I may not have the answer to
completely solve this problem, I would love to set up more
communication between myself and others who specialize in restoration
work. I feel it would be very beneficial to use this forum and maybe
more direct communication to share tips, recourses, and
I hope someone in the Orchid community can answer your question and I
hope more restoration specialists will post and share their
restoration questions . please feel free to contact me @
@Gary_Roe.

Gary Roe