The marking "S925" on silver jewelry means that the item is made of sterling silver, which is 92.5% pure silver. The "S" stands for silver, and "925" represents the 92.5% silver content, with the remaining 7.5% typically being other metals (like copper) to improve durability. Sterling silver is commonly used in jewelry because pure silver (99.9%) is too soft for practical use. S925 sterling silver is water-resistant
