Wow, talk about confusing! OK, next time I go to a show, how
will I know if what I'm buying is sterling? And, if .925 is mainly
silver and part copper, what percentage is then allocated to the
nickel and rhodium plating?
Sterling silver is 92.5 percent silver, and 7.5 percent copper. The
electroplated finishes that may be applied over the sterling silver
are not generally considered as part of the main metal content. An
error, technically, but since the plated layers are usually extremely
thin, their actual effect on the overall “by weight” composition of
the object is usually very little, probably not enough to affect the
legal definition of sterling silver… But I suppose you are correct
in wondering if it makes the marking for sterling silver inaccurate,
and it might indeed do so on things made of very thin metal
Personally, I prefer to buy only sterling silver that is not plated
at all. I don’t especially like the color of rhodium plating on
sterling. It’s an improvement when done to white gold, which often
is not all that white, but on sterling, though it does prevent
tarnish, the purpose of the plating, it totally masks the wonderfully
white color of the silver. Useful on things like those styles of
chains or objects where one cannot clean off tarnish, and an
oxidized finish on recessed areas isn’t desired. But I’d much rather
avoid it when I can.
By the way, I’d note that while I mentioned that the nickel
underplate layer on a rhodium plated item might show some magnetism,
I doubt that it would ever be that strong an attraction, due to the
very thin nature of that layer. And nickel is not that strongly
magnetic in any case. Also, in checking a few items I’ve got, only
some showed detectable magnetic attraction, using a rather strong
magnet. If the nickel barrier layer is very thin, perhaps you don’t
notice magnetic effects at all, especially if you’re not using a
powerful magnet. Of the things I checked in my scrap pile and
assorted sterling chains, most of the stuff I think is rhodium plated
showed at least faint attraction to my magnet, with is one of those
rare earth very powerful ones. Two items were strongly attracted to
the magnet, and in checking, I noted that both those scrap chains
were not marked, made of links that were just crimped shut, not
soldered, and upon further testing, turned out to be actually made of
silver plated steel wire. There were things I found at garage sale
lots, or the like, so who knows where they were purchased or
whether their owners thought them to be silver. Nevertheless, the
rhodium colored surface was otherwise indistinguishable from the other
rhodium finished stuff, an indication that suggests some care may be
needed in buying things from uncertain sources.
Peter
