Hey Michael,
What is your objective? Do you want silver to use? Or, do want to use that specific metal (if it's silver) because of sentimental associations? If you use this stuff, how will you do that? Lost wax casting? Pour it into ingots to roll or draw into fabrication stock?
We always found it easier to just toss the stuff into our scrap bucket to be sent off to a refiner. We usually sourced new stuff if we could.
You can get a vial of acid mix to test it for a few bucks, but it's a pretty cursory test usually relegated to distinguishing plated items from solid ones. Rio Grande has it. It likely can be sourced on eBay too. If you try this, it might be helpful to have a piece of known sterling to test too so you can do a comparison. This approach won't discern actual silver content percentage. You would probably have better luck with specific gravity calculations for that, although that can be a tad daunting.
Let us know how it goes. --Phil
