It is unlikely that you are going to receive .925 silver from most sellers in China, especially if the price is too good to be true. If the seller has negative feedback it is a good idea to read those feedback before making a purchase. One seller that you bought some silver from has many negative feedback about selling fake silver.
To see a sellers negative feedback, go to their feedback page and you'll see the number of negative feedbacks they have for that month, 6 months, etc....Click on one of those numbers and you'll see the negs for that time period.