Gold turning silk black

Jewelry Discussion
1

Awhile back I made a series of 14k yellow pave’ spacers for a triple
strand pearl bracelet and necklace set. The problem is that shortly
after it was strung the silk began turning black where it was rubbing
up against the gold in the holes of the spacers. Once it happened it
seemed like an obvious problem that I should have anticipated (sadly
I didn’t). It’s creating really very unsightly black stains on the
white silk of an otherwise lovely set. I’ve been having it restrung
periodically for the customer at n/c.

I have it all back now to restring and I am wondering if there is a
fix for this. I really can’t think of anything other than some sort
of grommet in each little hole (there’s about 90 holes). Any
thoughts?

Thanks,
Mark

2 
I really can't think of anything other than some sort of grommet in
each little hole (there's about 90 holes). Any thoughts?

Just a guess, but I suspect that if you stop off the outside of the
spacer to allow electroplating just the interior of the holes, where
the problem exists, and then put a decently thick rhodium plate on
it, that the rhodium inside the holes would be sufficiently hard and
resistant to wear from the silk, that it might not discolor the
silk. Also, be sure when the pieces are restrung, that there’s no
trace of rouge or polishing compound of any sort inside of the holes.
Even traces would allow the blackening. Also, advise the customer
that some cosmetics, if they get into those holes, act as polishing
agents, and just like a buffing wheel used even with white rouge,
the wheel turns black from worn off metal, and so would the silk. I
suspect that clean metal against clean silk would be unlikely to
cause the blackening, and that there has been either polishing
compound residue, or cosmetics (oxide pigments), dirt, or similar
materials that got into the holes while in the customers possesion
that is causing the problem. Avoiding that situation in the first
place, and making the inside of the holes harder via rhodium
plating, might solve the problem. At least, that’s what I’d try…

Peter

3

Hi Mark,

You could try having the piece re-strung with French wire wrapped
where the spacers are attached. Then you wouldn’t have any silk on
gold to discolor. This is the same idea used on the ends of a pearl
necklace at the clasp ends.

Mark

4 
14k yellow pave' spacers for a triple strand pearl bracelet and
necklace set [snip] creating really very unsightly black stains on
the white silk of an otherwise lovely set. Any thoughts?

Depletion gilding?

Noel