WarmGlass.com

So a bit of background first. I have some bullseye reactive cloud and it won't react with other glass in my microwave kiln. I wondered what would happen if I used raw, untreated copper wire, if anything was going to cause a reaction that would. What I have ended up with is the copper having turned a kind of gunmetal colour and a dark line formed at the glass boundary, it's not what I was expecting, but it is a great effect, anyhow I was going to look at pickling, or capping but I was wondering what happens if I leave the firescale. If I attempt to polish the piece, I get a little bit of the original copper, but not a lot so it looks like the firescale is pretty stable, but what happens to it over time?

I am also a little worried about the piece going green and rotting everywhere, can I stop that? If the copper goes a gentle green that would be fine I guess.

Any answers or photos much appreciated