Hello Charles
The other Charles (whom I like to call "Mister Argentium"), would probably give you a good answer :-)
You flatter me, the true Mr. Argentium is the inventor of the alloy
Peter Johns, I just try to help out where I can. Other posts have
given details of different etching solutions and techniques which
will work well on Argentium silver alloys; I would just like to add
to these comments by explaining how the germanium addition present
in Argentium silver alloys alters the electrical properties of the
Argentium alloys and is responsible for the difference in etching
rate reported by Carol in her post.
Argentium silver alloys contain about 1% germanium. Germanium is a
metalloid and an electrical semi-conductor and this relatively small
addition has a significant impact on the electrical characteristics
of the Argentium silver alloys when compared to traditional sterling
silver alloy (92.5% silver 7.5% copper). If I use the the
International Annealed Copper Standard where the conductivity of
annealed pure copper is a assigned a value of 100% and other metals
and alloys are rated relative to this then:
Pure silver 107 % IACS
Pure copper 100% IACS
Traditional Sterling Silver 96% IACS
Argentium 935 Original Silver 68% IACS
This difference in electrical characteristics shows itself in the
amount of current required to either get the alloy to etch or weld.
Others have commented on their practical experience of this in other
posts.
Charles Allenden
Argentium International