What does rci mean on a 10 carat chain?

The "RCI" marking on a 10-carat chain typically stands for "Rhodium Coated International," indicating that the piece has been coated with rhodium to enhance its appearance and provide protection against tarnishing. This finish gives the jewelry a shiny, reflective quality. It's important to verify the authenticity and quality of the chain, especially if it is marketed as genuine gold.