I was playing with some reverse electro plating.
I was using water, salt, vinegar, 4-D cell batteries, a gold plated sterling silver medal, and a copper penny.
After running the process for 1/2 hour the gold plating on the coin turned black. I thought ewwww, thats horrible, and scrapped the black stuff off the medal, and it left a nice silver medal behind.
The I flushed the BLACK coating DOWN THE DRAIN, and cleaned up.
Is this black coating the actual gold??? If it is I didn't know it at the time
If I redo this for other medals, can the black stuff be melted in to gold again?