Many of my students work with silver because of its low price and
ease of fabrication as well as casting. Traditional sterling, alloyed
with copper, has many drawbacks, mostly because of its fire-scale and
high tarnish properties. I don't recommend this copper alloyed
sterling to my students, and I don't work with it myself.
Argentium is a copper alloyed sterling which has a minute amount of
germanium added, which forms a surface barrier to fire scale and
tarnish on the finished work. It also imparts an amazing ability to
fuse to itself. These make for excellent qualities, except for the
extreme fragility it has when hot. As long as you don't try to move
it when hot, like when annealing or soldering ( or fusing) it works
great. My students working with lots of wire for chain links love the
way Argentium balls up and fuses.
Another sterling alloy we use lots of in our studio is one called
S57NA, which is available through United Precious Metals. They also
sell the S57NA alloyed sterling as sheet and wire stock, too. We like
the S57NA sterling because it has minimal fire-scale and tarnish
qualities, and also is quite stable and strong when hot. I fused some
small 20 ga. jump rings made with S57NA sterling wire last week, and
I was unable to see the fused joint afterwards.
There will be many opinions expressed here on this forum about the
advantages and drawbacks of traditional sterling, Argentium, and the
S57NA Sterling, as everyone has their own preference. I can find many
advantages to both the Argentium and the S57NA sterling, but very few
for the traditional sterling.