Silver comes in several forms.  Not all silver is .925 Sterling.  Alpaca Silver, also called German Silver or nickle silver, was first used in China as a substitute for sterling silver.

The vast majority of my jewelry is high quality .925 Sterling Silver (or 14k gold).

Occasionally I offer some less expensive metals, such as Pewter or Mexican Silver.  When I do, this is clearly noted in the description of the piece.