Etching Argentium Sterling

Hi Kerri,

Since I have not yet had a chance to try etching Argentium Sterling
myself, I forwarded your question to Sam Davis, a chemical engineer
at Stern-Leach. He gave the following answer:

Yes, Nitric acid will etch Argentium. I haven’t used ferric
nitrate, but I predict that if it works for regular sterling,
it will work for Argentium as well. Ferric chloride is a known
etchant though. We avoid using nitric acid on Argentium because
it takes off the germanium/germanium oxide layer which is what
gives the alloy superior tarnish resistance. Nitric will also
react with silver and copper very aggressively. The reaction
(with regular sterling or argentium) produces a very toxic
brown gas which consists of nitrogen oxide

So, Kerri, I think the answer is to go ahead and do your etching
project. As always, be sure to have good ventilation!

P.S. I forgot to add that it will be important to heat the Argentium
Sterling in the presence of oxygen in order to speed the generation
of a protective, tarnish-resistant layer of germanium oxide after
etching. This could be a soldering operation, or heat/precipitation
hardening, or simply putting in an oven at 250 degrees F. for 10-20

Let us know how it works!
Best wishes,
Cynthia Eid

Hi, I want to report that I successfully etched Argentium Sterling
with ferric nitrate the other day. It worked fine—no problems. I
got a nice, deep, clean etch.

I also want to offer another tip for bubble prevention. I usually
place an aquarium pump on top of the tupperware container to create
vibrations (as Karen Christians so kindly took the time to teach me,
one afternoon). However, recently, I needed to etch, and I had lent
my pump to a friend. So, I put it on top of the washer and dryer
while I did laundry----it worked great! And, I imagine that the heat
from the dryer was a help, too.

Cynthia Eid

Hi Cynthia:

I want to report that I successfully etched Argentium Sterling with
ferric chloride the other day. It worked fine---no problems. I got
a nice, deep, clean etch. (snip) 

I thought ferric chloride would only etch copper - I’ve never gotten
it to etch sterling in any way. If it will etch argentium sterling,
then indeed I’ll have to buy some (argentium sterling).


Cynthia, I do a lot of etching, and have always had to use ferric
nitrate to etch silver ($35 a jar at Bryant Labs, when you can get
it) rather than ferric chloride ($4 a bottle at every Radio Shack in
the country). Are you saying you can use ferric chloride to etch
argentium silver, even though you have to use ferric nitrate to etch
regular silver? (I have had great results etching nickel with ferric
chloride). If so that is great news. If that is a slip of the
keyboard, hey, it is Monday out here in California too.

I etch silver with the aquarium pump setup, and your suggestion
about etching on top of the washer/dryer is brilliant. My washer and
dryer are right next to my studio, so why didn’t I think of that?
Duh. Serious agitation and heat all bundled together in one nice
package (I’m using a heating pad/aquarium pump combo in the studio).


Cynthia, Do you really mean ferric chloride?

James McMurray

My apologies, folks! I meant to say that I etched with ferric
nitrate----the same chemical that one would use with regular
sterling silver. It was late at night—I guess I was more tired
than I realized? Sorry for any confusion!

Cynthia Eid