On Wed, 11 Feb 2004 20:31:53 -0800, in rec.crafts.jewelry "Charlie"
wrote:

I've designed a sterling silver bracelet made from twisted wire and would
like to tarnish it so that it goes black in the cracks of the twists,
similar to the look found on bali silver beads. I've read that the thing to
use is "liver of sulphur". Now, I can't find this for sale in the UK, and
boyfriend doesn't really want me to have toxic chemicals in the house as we
don't have good ventilation. I've also been recommended "Silver Black" by
an American friend, but alas - I can't find that either.

Silver black is a bit worse, if I recall, that liver of sulphur. That is just
a somewhat impure mix of potassium sulphides. The key is the sulphur. almost
any liquid that contains free sulphides will tarnish silver. If you go to the
local gardening supply store, they may have garden sulphur products used for
mold/mildew on plants I think. not quite sure of the use, but the stuff is
commonly enough used. Get a liquid product if possible, as I've seen some
straight sulphur powder used for this as well, which isn't as suited to the use
of tarnishing silver. The reason sulphur is important here is that in general,
the black tarnish on silver that forms, is silver and copper sulphides, so
that's what you're trying to generate on the silver. Much slower, but also
effective, are eggs. especially (yuck) rotton ones... But the stronger
sulphur chemicals will give you a more even finish. Normally, the way this is
done is to dip the piece so the whole thing is oxidized, and then you polish it
back off wherever you don't want it. With stronger solutions such as silver
black (or a stronger mixed home solution), you can also paint it on just the
desired areas. Less polishing after. But dipping in a dilute, warm, solution
gives the most control as you can watch the color develop and stop it when it's
enough. if it gets too thick, it can flake back of again.

Someone else told
me vinegar would work. Now, I can see that it would, as obviously vinegar
tarnishes silver, but how exactly would I go about doing it? Just dunk the
whole bracelet into the vinegar and then polish it up? How durable do you
think this finish would be, and how black should it go? I was wondering if
anyone has any experience before I go wasting expensive wire!

Well, your process is about right. But vinegar? In 35 years of making
jewelry, that's the first time I've ever heard that line, and while it may seem
obvious to you, it does not to me. vinegar is an acid, containing no sulphur.
Acids generally act on metal to dissolve oxides. if anything, vinegar might
clean the silver if there are oxides (they'd be probably of copper, not
silver). Certainly, with a bit of salt added, it does a nice job cleaning
copper. If you're experience is with vinegar tarnishing silver, then I suggest
that you're thinking of more complex food products that might contain vinegar,
but that the vinegar is not the agent actually tarnishing the metal. A number
of vegetables and spices, that might be mixed with vinegar in pickled products,
will contain various sulphur compounds, for example. But are you sure you're
not confusing your memory with eggs? Those are notorious for tarnishing
silver.

Oh, as to durability...

Properly "oxidized", or 'tarnished", or "antiqued", (all terms used to
describe the black finish, which as i've noted, is made up of silver and copper
sulphides), the finish is reasonably durable where it's protected from
abrasion. And in areas getting just mild wear, it sort of restores itself as
quickly as you wear it down, since of course silver does tend to tarnish over
time, all on it's own.

Hope that helps.

Peter Rowe