Rio tech thought the chain may have become coated w/ steel from the
I think it's more likely the goldfill parts of the chain became
coated with silver from the silver parts of the chain. Steel is so
much harder than the metals in the chain, it won't have rubbed off.
But soft silver might have rubbed off on the harder goldfill, if the
goldfill surface were even slightly rough, and maybe even if
polished. If the goldfill is now lightly coated with silver, try a
brief, dilute (I'd try around a 10% solution), nitric acid pickle.
Test on a very small portion first. If the goldfill is intact, it
won't be dissolved, though it might discolor. The silver would be
dissolved, though, getting you back to goldfill and silver colors.
You might then have to start over with cleaning if the acid
discolored the goldfill. Be careful with tumbling dissimilar metals
together. If you can buff/clean with mechanical manual means, like a
brush, 3M bristle disk or buff, you avoid those problems, but with
those methods, it can be difficult to reach all surfaces, and if
significant amounts of the metal remain uncleaned, then it will be
harder to tell the difference in colors sinch much of the surface
areas will still look too much alike. Good luck. This, by the way, is
one place where magnetic pin finishers are superior.
The tiny pins work fast enough, and get into all the crevices, to
burnish your metal, meanwhile your piece is not rigorously burnishing
itself against itself, the way it might do in a rotary tumbler with
standard steel shot.