A few months back, I interviewed a metallurgist from United Precious
Metals on my weekly Blog Talk Radio show, which I do every Thursday
afternoon from my studio. It is archived if you want to hear it. In
that interview, the metallurgist explained that Peter Johns did in
fact patent Argentium with a specific ratio of germanium in the
alloy. Pretty neat stuff, except for the way it gets very brittle
when it’s hot.
United Precious Metals did their own research into using germanium
in a sterling alloy, and they discovered that a smaller ratio of
germanium in their alloy produced the same low
fire-scaling/staining/tarnishing effect as Argentium. However, UPM’s
metallurgist claims that their patented germanium containing alloy is
less brittle when hot, unlike John’s Argentium. United Metals
patented their lower ratio of germanium containing silver alloy.
Since we often alloy our own sterling in my studio, we can
experiment with alloys, and find what works best for us. United’s S57
NA alloy ( with the germanium ) seems to be a great working alloy,
and puts any copper based sterling to shame, in my opinion.
Unfortunately, this great S57 NA alloy is not yet available in sheet
or wire stock commercially, so you’ll have to alloy your own to try
it out. One of my students called United Metals asking about the
different characteristics their alloys had, and they were nice enough
to send her a few free samples to try out. How nice is that?
I really hope that this helps promote a dialogue about alloys, their
pros and cons.