What does 25G MSU stamped on jewelry mean?

The marking "25G MSU" on jewelry typically indicates that the piece is made from a base metal that has been plated with 25 grams of gold. The "MSU" could refer to the specific manufacturer or brand responsible for the jewelry. This marking suggests that the jewelry has a significant amount of gold plating, offering some durability and value, but it is not solid gold. Always check with a jeweler for more specific information about the piece.