I’m always being asked how to oxidize (also referred to as antiquing, tarnishing) metals. There are a number of different methods. Permanent articles are posted on Beading Help Web’s Basics page.
Liver Of Sulfur is quick and produces excellent results. Purchase LoS at a jewelry supply store or rock shop (most craft stores, like Hobby Lobby or Michaels will NOT carry the chemical). LoS can be purchased in solid form or liquid. Use care with either method, as the chemical is toxic – gloves and eye protection are recommended. After immersing the piece in warm LoS or painting the components to be antiqued, rinse well and dry thoroughly.
Hard boiled eggs are also an easy to use method, inexpensive, and more environmentally friendly than LoS. The downside to “egging” your jewelry piece is that it takes a bit longer. I’ve worked with my egg method, and have found that using hot, straight out of the boiling water, eggs work best. Place the jewelry and unpeeled eggs in a ziplock bag, close the bag (but leave a small opening to allow for expansion), and crush the eggs through the outside of the bag using a spoon or bottom of a plastic cup. Close the bag tightly, and walk away. I like to turn the bag over a few times, about every 10 minutes, because the metal touching the surface that the bag is sitting on won’t oxidize as well.
Finally, a new method of oxidizing that I’ve found for copper is to heat it. An oven (NOT A MICROWAVE) can be used – experiment with different temperatures and length of time for different results. About 30 minutes at 300 will produce swirls of purples, blues, browns, and oranges…30 minutes at 400 will achieve a brassy gold color (I’m an alchemist!!!).
I generally oxidize finished jewelry, unless some of the components won’t mix well with the method I’m using. In that case, oxidize only the metal components that you want antiqued. Most non-porous stones will be fine with any method, but if you are in question, test on a spot or broken bead/stone first. With all methods, use tarnish remover, very fine (0000) steel wool, or a tumbler to remove tarnish from surface areas after oxidizing.