Not sure where this should be posted but it is a coin from Mexico so here it is. It contains silver and I purchased 4 of them 30 years ago at junk silver prices. One is dated 1947 and the other is 1948.
Yes the .500 is the silver content, 50%. Nice pesos, for the junk bin. Silver is low right now so the melt value is $4.29 each. As collector coins they are common and NGC only lists them in MS 60 for $8. I figure they are worth $5 each.