My town libabry redecorated the interior about 5 years ago. Included in the job was re-guilding some decorative plaster strips in the ceiling-I belive it was quite expensive.
i happened to look up at one strip-and it had turned green! Now, i thought that gold did not oxidize or tarnish-so was the re-guilding done with some metal which was NOT gold?
Shouldn’t gold lef be good forever?
Take a look at this gilding glossary.
Key points:
[my emphasis]
To be honest, I’d be a bit surprised if a town library could afford to have its ceiling decorated with gold leaf. The material seems to come in at about a dollar per leaf (5.5"x5.5"), so might not be such a huge deal unless there’s lots of area to cover, but I would imagine the labour cost might be fairly eyewatering - it’s not the sort of thing your average painter would be able to do.
Since it turned green, I would suspect that it’s copper and not gold.