Dating vintage jewelry has never been easy and it always helps if you find out a few tricks to at least give you a place to begin. Here is some information on dating Taxco Sterling Silver Jewelry.
'In the first half of the 20th century silver items manufactured in Mexico were marked simply "silver" or "sterling". Usually a location (Mexico or a town name) and silver fineness (925, 925/1000, 980) was included.
In 1948 the Government of Mexico promoted the reintroduction of the "eagle mark" to identify the manufacturers of silver items. The "eagle" was stamped with a number associated to a silver manufacturing company. This system was unsuccessful, eagle stamps were misused or "loaned" to more than one artist of maker and was abandoned in the 1980s.
It was substituted by the "letter and number" system still in use. In the "Letter and number" system a letter identifies a location (T for Taxco, M for Mexico City), the second letter is the first letter of an individual's first or last name of the maker. The number is the number of registration of the maker.'