I'm no expert but enjoy helping when I can... so some ideas:
1. Lead is soft, and you can buy test strips to detect lead paint. Presuming that these strips react with lead itself, and not a different component only found in lead paint, you could use one of these to figure out whether this is lead or not. The strips are available online or at most hardware stores.
2. Silver can be tested using an acid solution which is also available online.
That's about all I know, I'll leave it to the real experts to chime in further...