I have about 150g of silver contacts trimmed with a little copper left. I mixed about 300ml ~12% HCL and 100ml 3% H2O2 and added maybe 10g of the copper I trimmed from the contacts, just to try and get the solution going but it wasn't going green so I added all the contacts(non-magnetic) and it started turning green. Came back maybe 20 minutes later and there was a black haze/cloud around the contacts at the bottom of the solution. What could this be? I believe I have added far too much HCL and H2O2 for the amount of contacts present, is it possible it is silver chloride? I gave the glass a swirl and it disappeared.