I've never cooked with any type of copper cookware before and I bought a vintage Revere 10 in. copper bottom pan to try out. After I cooked something in it I sat it on a cool burner for a little while and washed a few dishes, then put the Revere pan in the sink and started washing it. As soon as I turned the pan over to wash the outside I saw that the copper had basically disappeared! I know I should not have put it in the sink before it was completely cooled but I didn't think it was that hot and I didn't know the copper could just wash off. Btw, the pan did not warp and still sits flat. Did I ruin it because it was too warm when I washed it? I can't find any information on this. Thank you!