Does copper migrate through silver?

COuld it have been extremely thin silver plating that has worn off with usage of the receptacle ?
Also silver tarnishes (silver sulphate) ... perhaps it's just tarnish you're seeing ? I don't think copper will migrate through silver at room temperature.

Subaruguru. Why should silver sulphide (tarnish) have a similar smell to hydrogen sulphide ? Are you suggesting that all sulphur compounds smell the same? Have you ever smelled sulphuric acid? Doesn't smell much like hydrogen sulphide. Tarnish is silver sulphide.
It was common for babies in England to receive a silver egg cup for their christening. The joke is that silverware is completely inappropriate for use with boiled eggs since the eggs contain sulphur and therefore tarnish the silver extremely rapidly. Try breaking a soft boiled egg on a silver plate sometime and see what happens.