And I don't mean ecologically sound.
I've heard about jewellery turning your skin green, never meant to be an indicator of high quality metal, but I've not come across jewellery itself turning green before.
This is what's happened to a bracelet I made a couple of years ago.
I've given it a bit of a clean up with a silver-polish impregnated cloth but the greenish tinge still remains. Next I'm going to do some more heavy-duty cleaning which will at least clean up some of the oxidisation.
The core of the bracelet is silver wire, with finer silver wire wrapped around it, and the ends are 9ct gold hollow beads. All I can think is the solder used to fix the beads and the finer wire to the main bracelet was low quality and this has caused the green to appear.
Any other ideas anyone?