What does 925 mean on gold jewelry?

The "925" marking on gold jewelry actually indicates the silver content, not the gold content. In this case, "925" means that the piece of jewelry is made of sterling silver, which is an alloy of silver that contains 92.5% silver and 7.5% other metals, usually copper.

Gold jewelry is typically marked with a different set of numbers that indicate the purity of the gold. Common gold markings include "375" for 9 karat gold, "585" for 14 karat gold, "750" for 18 karat gold, and "999" for 24 karat gold.