Found necklace in the water today, not sure if gold/silver. How do I clean it?

[Wallhangers]

The shallow lake I found this in has a lot of marl and might be why it is dark. The necklace is non-magnetic and feels kind of heavy. Please let me know what I should soak it in or scrub it with. I tried a little bit with toothpaste and brush but maybe it needs to soak initially? Thanks in advance.

[rodgerdodger]

Put it in jewelry cleaner . If its gold it will turn out nice .
Or you could stick the end in some vinegar to see if its copper.
Good luck.