925 Silver Pendant, Key and Lock Model. The number 925 represents purity, the percentage of pure silver in the composition of the "925 Silver Pendant, Key and Lock Model." The 925 means 925 or 92.5% pure silver! By combining other metals with pure silver, jewelry is produced that is very resistant to scratches and shocks. 925 silver represents the most well-known formula, a mixture that consists of 92.5% silver and 7.5% copper and is known as Sterling Silver. Jewelry made from 925 silver is a good choice as you will have a piece with high silver purity and increased durability over time. Silver jewelry is for a lifetime, can tell a story, and can be connected to events in our lives.