Discoloration on silver

My tumbler came with what appears to be a corncob medium treated
with polish (for brass gunshells). I used this on a bracelet of fine
silver, and it came out covered with a dark film. After cleaning and
retumbling–this time with Sunsheen porcelain and burnishing
soap–it is just as shiny as the other bracelets, but still darker.

It’s hard to describe the difference between this bracelet and the
others. The metal doesn’t look like fine silver anymore. Actually,
it reminds me of a chrome car bumper!

It doesn’t respond to any tarnish treatments (Flitz, lemon juice
with salt, baking soad with salt, toothpaste). Any suggestions?

Janet

Janet, Hi, I’m new to the boards, been lurking awhile. As I’m a
student of jewelry have been reluctant to post. But I may have
encountered your problem. Could it be fire scale? If it is, the
solution is to lightly anneal the piece and pickle it several times
and brass-brush it to finish. You may have to anneal the silver five
or six times.

Miri

Hi, Miri. The bracelet is made of fine silver, so firescale isn’t
the problem. I think the change in color came from the polishing
compound or the corncob medium. No idea if it’s residue or a stain.

Janet