How can I determine if a platter is real silver?

I found a platter that is very intricately designed and is pretty heavy. It has a lot of tarnish and possibly burn marks from being used in an oven. I am still searching for small print on the back but so far the only thing that I have been able to locate is what appears to be a very small crown on the bottom. The crown appears to have been imprinted using a dot-to-dot method. Is there any significance to that crown?