They drain the water from our local pool in the park I always try to get to it before it's refilled for the summer well I finally got out there today for a few hours got a dollar or so in change two wheat backs and this lovely bracelet .
It's more like a big pond they pump last yrs water out into the near by canal then ad fresh sand refill and chlorinate it's very nice I should post pics sometime
Do the foil test (Wrap in foil and spit, leave for 15 seconds, and then smell it. Sulfur smell indicates Silver.). That's a good starting point. You could also do hot water, aluminum foil and baking soda... It'll remove tarnish from silver lickity split. Might make it easier to read the hallmark.
Thought I'd show the clean version of Sundays find .
I believe it is silver but I don't know what the stones are but there's lots of them it may be old it was under the sand layer in the clayish pack