I've played around for a long time to learn how to create different colored patinas on my copper jewelry. I've decided to share some of the techniques & tips so that you can do it too!
The blueing chamber is simple, just take any plastic container with a lid. In this one, I put ammonia on a cotton ball, added the copper and put the lid on tightly. You leave this in until you get the color you want. The copper should not touch the ammonia, it's the fumes that do the work.
You can also add the ammonia to sawdust, this allows for additional saturation which leads to the deeper blue color. If you sprinkle the pieces with salt, those spots will stay copper and make an interesting affect.
Once you have the color you like, just wash the piece with water and flake off any of the loose patina. You will have to seal the blued pieces. I just use a Krylon clear coat in a few light layers.
Here's a finished piece of jewelry using the blueing technique!