I have had several questions on Silver content in Jewelry so I thought I might offer some of the information I have come across. Silver content in jewelry is usually marked by a stamp depecting the amount of Silver in the item, ie. 925, 835 etc. There are exceptions to this, for instance Native American Jewelry and Arts and Crafts items made by Hobbiest or Jewelrers. Some of the Artist do not own a stamp and since they are not required by law to stamp them, they do not invest in the money for the cost of the stamp or the time it takes to stamp each item. Many countires govern these standards, some more closely than others. Mexico has a very stick standards which is why they not only have items marked 925 but also with the artist Initails. This was done so the Mexican Goverment so they can collect taxes on it, ie. TS-7  means it was made in the city of Taxco and the S is the first letter of the silversmith last name. The 7 means that he or she is the 7th person with that letter.