I've wanted to play around with oxidizing—intentionally darkening— some silver pieces for a while now. About a year or so ago (probably longer, now that I think about it) I bought a small rock of liver of sulfur from an Etsy seller with every intention of testing it out on a small batch of silver. Well, I never got around to it and, long story short, it had gone bad by the time I tried it. "Yeah, that happens after a while..." my husband informed me. (Helpful now, honey, thanks. lol)
Well, I was working on a custom PMC piece for a friend to give to his wife for Christmas and that was going to be the piece that I successfully oxidized. To the Etsy forums! I had read before about using eggs to oxidize silver, so figured what the heck, I'd give it a try. It's really simple, actually. And not toxic. And not to mention good in salads.
The photos are from a new batch I just did the day before yesterday. You simply put your pieces to be oxidized into an airtight container—I prefer a clear one because I can check on them without disturbing them too soon. I used two eggs. You want the water to boil before adding them and then boil them for about 15 minutes or so. Once hard boiled, remove them with a spoon from the water and cut them open with a knife, quickly transferring them into the airtight container, sealing the lid. You want to move quickly because the heat and steam help the sulfur from the yolks darken your pieces.
Once they get to the desired darkness, you remove the lid, clean the egg off of the pieces by rinsing and wiping with a paper towel and then use very fine steel wool (I believe I used 0000 grade) to remove the oxidation in the raised parts of the pieces as you like.
I actually tried this batch first, removing the whites from the eggs once boiled, but they cooled too quickly that way and mostly my pieces just turned a funky yellowish color. Not very attractive. I boiled a couple more and just halved them and put them in the container and had much better, darker results.
These are a few of the pieces all polished up using steel wool. I imagine I will keep practicing, but I'm really happy with the results overall!