Hello all, I was reading the "green ring " thread and it reminded me
of something that has happened to me three or four times in the past.
I give a customer a brand new, clean silver ring and they call me
about a week latter to complain that it is turning their finger black.
I’ve never been able to figure it out. These are not people whose
skin usually reacts to silver, and I always soak my jewelry in water
after pickling/oxidizing/polishing to remove chemicals that might be
there. Any ideas? -Jade @Jade
Silver tarnishes in the presense of sulpher, among other chemicals.
Depending on where your customer lives, there may be trace sulpher in
the water, and who knows what chemicals in stuff like shampoo, soap,
hand cream. etc.
Sell them a little polish cloth as an add-on sale!
Cheers
Virginia Lyons
Hi; I also have run into this with lower karat golds. To my
understanding and observation of what I do to metal, it is usually
after potato chips, doritos, and other products with lots of salt and
preservatives. I believe it is a chemical reaction from the body
eliminating these wastes. perhaps a mild nitric acid id being
produced by the body… have a nice day…John Henry
I give a customer a brand new, clean silver ring and they call me about a week latter to complain that it is turning their finger black. I've never been able to figure it out. These are not people whose skin usually reacts to silver, and I always soak my jewelry in water after pickling/oxidizing/polishing to remove chemicals that might be there.
Hi Jade, That has happened to us also in the past, and even though
Shawn is very careful to remove all traces of polishing compound (that
he can see) that is usually the problem…he has been using a
toothbrush and dish liquid to clean pieces for the past few years, and
we have not had it happen since. Lydia MistressJewelry
Hello Jade; Sterling silver not only reacts differently on different
individuals, it can react differently at different times on the same
individual, depending on their body chemistry at the time. You can
work with fine silver, but it stays a little soft compared to
sterling. Even so, it will react to some degree unless it is reagent
pure. All you can do is address the problem on a case by case basis.
You can design to minimize surface contact with skin, or use a
bi-metal lining on rings with the gold on the inner surface. I don’t
recommend plating, since it’s porous to some degree and ultimately
can’t prevent reaction for an individual with very acidic skin, as
well as being a dissaster when it begins to wear off. And some
people will just have to be informed that “such is the nature of
silver”. I’m sure you’ll get lots of from the others
here on our forum, so I’ll leave it at that.
David L. Huffman
I have the same problem with a gold ring I made that I wear all the
time. Every once in a while I’ll look down and my finger will be all
black under my ring. I’m like “Oh my God, don’t anybody look”. this
usually happens when I’ve had Italian food or a lot of garlic. It has
to be a chemical reaction. Embarrassing though. 
~Poppy~
Jade, This info came from a customer several years ago. She was taking
a prescription drug to help with her acne and one of the side effects
(if you can call it that) was that she was no longer able to wear
silver without it turning black. I don’t recall the exact drug she was
taking but it obviously changed her body chemistry. Just another thing
to consider.
Leda
These are not people whose skin usually reacts to silver, and I always soak my jewelry in water after pickling/oxidizing/polishing to remove chemicals that might be there. Any ideas?
Do you quench in water before pickling? Many jewelers will quench in
pickle after soldering the piece. This can lead to entrapment of acid
within the metal which is not removed by water or even an alkaline
bath., but can leach out after it is worn. This may be your problem.
....I have the same problem with a gold ring I made that I wear all the time.... this usually happens when I've had Italian food or a lot of garlic. It has to be a chemical reaction.
G’day; It could well be. Onions, garlic and many other foods contain
complex sulphur compounds, and some medicines contain sulphur too.
Pure gold will not blacken with sulphur, but gold alloys containing
copper and/or silver will blacken. Then there is another point
to consider. Ever wonder why mineral oils which have been in contact
with moving parts are invariably filthy black? Most of this blackening
is due to extremely fine particles of metal mixed with the oil. Ever
cleaned brass, copper, silver etc., with domestic metal polish? The
cloth gets very black, and this is due to the very fine metal gently
abraded away. Remedy for blackened ring fingers is - I’m afraid - to
just clean the offending finger and ring. If common soap and water
isn’t always available, you will find a cleansing cream will do the
job easily - if used frequently. Cheers –
John Burgess; @John_Burgess2 of Mapua Nelson NZ