The number 925 stamped on a gold piece of jewelry usually means that the jewelry is not entirely gold; it is sterling silver that has been gold plated. The number normally indicates the purity of the silver used, not the quality of the gold.
Jewelry Making : Does Gold Jewelry Have To Be Stamped?
Gold jewelry has to be stamped with the number of carats according to the 1906 National Gold and Silver Marking Act to …