After my failed attempt to oxidize silver with a boiled egg, my next experiment was oxidizing with lime sulfur, and I thought I'd whip up a quick tutorial, since I had not seen one online for this method. Lime sulfur is easily found at a garden center and relatively inexpensive (about $10). It is a potent chemical, so be sure to use gloves and work in a well ventilated area - it stinks like rotten eggs (that's the sulfur for ya!).
I never found detailed instructions mentioning time or specific measurements for this oxidation method, so I just made some educated guesses the first time I tried this. I used this method to oxidize a few jump rings.
I placed about ¼ cup of hot water in a plastic container (cut off bottom of a soda bottle) and added about four drops of lime sulfur (just eyeballed it out of the bottle, though I may try to get a dropper for better control next time). I added my sliver findings and let it sit, checking on it every five minutes or so, and giving the liquid a little swish.
After about 20 minutes, the silver had completely oxidized to a dark gray finish and I removed the silver from the wash. I rinsed them off thoroughly, of course.
I like the gray finish, but will try this experiment again to see if a darker finish can be achieved if I leave the silver in the wash a bit longer.
And here are a pair of rose quartz earrings I made with my oxidized findings.