Well, I won an auction on Ebay and I didn't paid (and received, of course) this medal. So, I cannot tell you more about it.
I asked you about the purity of silver because, the seller put for sale the same medal with 2 diferent info about silver (first time - 800\1000 silver; second time when I bought it - 1000\1000).
A nice person from another forum about coins told me that it is possible to be silver 925 and he gave me this link:
http://charlessnowdencoins.com/proddetail.php?prod=14197385
Sorry for my English!