jewelry questions...

[notanotherxerox.livejournal.com]

I'm making some pendants and have a few questions:

What type of metal for a chain or bail doesn't tarnish or oxidize? I'm pretty sure sterling silver doesn't, but will silver plated or gunmetal?

What sealer/varnish works the best for making the pendant waterproof? I'm using Delta Ceramic exterior/interior varnish but I get mixed results so I wanted to know if anyone can recommend something better.

Thanks!
xoxxo. Tabitha