So I finally get a tumbler. I run it with only Dawn, water and the steel shot for 2 hours as suggested in a tut that I found. I then, not wanting one of my silver pieces to be the first thing I experiment on, throw in a roundmaille copper necklace, clean water and more Dawn. The first time I left it in for about 90 minutes but the piece still looked a little dark so I rinsed everything, threw in more Dawn and tried again for about 90 more minutes. When I opened the tumbler the next time, the piece is quite dark (almost black) so I figure something must be wrong. I was using Dawn ultra so I go and pick up some regular non-ultra blue Dawn and try again. Now, after the third run in the tumbler, the formerly copper piece is very shiny and smooth but almost the same color as my stainless steel shot. What did I do? I certainly don't want to put any of my silver pieces in this thing if they are going to come out some color other than shiny silver! Thanks in advance for any ideas.