The reason sterling silver requires the mixture of other metals is because naturally, pure silver is soft. Adding other metals to the silver increases the hardness, making it more suitable and durable for use in jewelry and housewares like silverware.
The result of this process also produces that signature silver color: bright, shiny and metallic. The only downfall of this beautiful metal is that it can tarnish, which is why it’s important to regularly clean and maintain sterling silver jewelry with polishers.
The purity of silver lands on a numeric scale, or rating system, based on 1,000. Pure silver gets a 999 rating. In order for a silver to be classified as sterling silver, it must meet at least a 92.5 purity, AKA 925. Donc, as you can see: 925 silver is sterling silver.
Conversely, metals that contain less than 92.5 percent silver are not sterling silver, which is important to keep in mind when buying sterling silver.