Pure silver is soft, too soft to create durable jewelry, so it’s mixed with other metals to enhance performance. One popular silver mixture is known as sterling silver.
Silver has been used to make jewelry since ancient times, but the exploration of continents in the western hemisphere uncovered productive silver mines that greatly increased the supply of this precious metal. The result is that– more silver has been mined and used since the late 1700’s than in all prior centuries combined.
The minimum silver content can also be stated as 925 parts per thousand of pure silver, so you might see the figures 925 or 92.5 used to designate silver content.
The US Federal Trade Commission (FTC) stipulates that jewelry sold in the United States cannot bear silver markings or be described as silver, solid silver, sterling silver, sterling, or with the abbreviation Ster. unless it contains at least 92.5 percent pure silver.