Greenish-blue patina on gold?

Thank you everyone for helping me with this 24k finish. But does
anyone know how to make a greenish/blue patina on gold? It looks a
lot like when copper oxidizes, and looks very cool.

Thanks,
Janet

Janet, you may try copper coating it with old, used, copper filled
pickle and an iron nail. It’s an old plating technique. After it’s
been plated sufficiently, pull it from the pickle, neutralize and
clean it well without scrubbing off the new copper plating. Then
spray it with salt water or vinegar and salt and stick it in a closed
container with a small container of household ammonia for a while.
The ammonia fumes will, over a short time, bring out a very nice
copper patina. You could mask off any areas that you don’t want
plated with melted wax before dropping it into the old pickle. After
it has fumed to the desired color with the ammonia you can polish off
the parts you want to be gold and leave the patina where you want it.
It’s just a suggestion.

Mike