Coral Precious coral or red coral is the common name given to Corallium rubrum and several related species of marine coral. The distinguishing characteristic of precious corals is their durable and intensely colored red or pink skeleton, which is used for making jewelry. Red corals grow on rocky sea bottoms with low sedimentation, typically in dark environments—either in the depths or in dark caverns or crevices.
Rhodium is a noble metal with a whitish gray appearance, and it is typically applied to metal through electroplating. A plating of rhodium is applied over either sterling silver or alloys to give a piece of jewelry a bright, glossy and long-lasting finish.