What does Pl900 mean on a ring?

The marking "PL900" on a ring indicates that the metal is composed of 90% platinum and 10% other metals, such as iridium or ruthenium, which are often added to enhance durability and strength. Platinum is a precious metal known for its rarity and resistance to tarnish, making it a popular choice for fine jewelry. The "900" signifies the purity level, reflecting the high quality of the platinum used in the ring.