Continuum Is a tarnish resistant Sterling. It will still tarnish in
the presence of sulfur. We all know there are many foods that are
high in sulfur, itis a necessary nutrient in our bodies. It is also
a common fact that all sterling silver will tarnish in the presence
of sulfur. Some other major contributors are loading gun shells
because of gunpowder. Also MSM, DMSO, Are some of the biggest
contributors in tarnishing of sterling silver. I would guess that
there is nothing wrong with the ring. Sometimes we just come in
contact with the wrong chemical at the right time. You can do it
test and compareit against other Sterlings in your shop, and it will
give you a great idea of where it stands.
All sterling silver alloys will tarnish when exposed to sulfur
compounds some faster than others but if you can patina it with
liver of sulfur it will tarnish. Another source of aggravation is
strong chlorine compounds that will produce some silver chloride on
the surface which will darken with exposure to sunlight.
I have had people manage to do this in hot tubs and mineral baths,
or in areas where the well water is high in hydrogen sulphide or
other sulfur compounds typically from anaerobic bacteria in the
ground water or issues with hot water tank anodes or low tank
temperatures. Anyhow while not super common it does happen.
Obviously the ring came in contact with something that caused the
oxidation. but I am unable to uncover what as my clients live in
Jim, Many swimming pools today are salt water pools rather than
chlorine. They turn silver black. If they travelled to an ocean on
the coast, that would certainly do it too. I assume the problem is
environmental rather than a result of body chemistry since it
happened to both their rings.