I bought it at JCPenney a couple years ago, it was marked sterling silver, but the acidity levels in my skin wore it down a bit. 90% of my jewelry is either sterling silver or 14k.
It says in the description - Approximately 7.5. I wear a 6.5 and this is loose on my finger. My thumb fits anywhere from a 7.5-8. So that would be my assumption.