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 in making jewels.
Red corals grow on rocky sea bottom with low sedimentation- in dark environments—either in the depths or in dark caverns or crevices.
The original species, C. rubrum, flourishes in the Mediterranean Sea. It grows at depths from 10 to 300 mt.
Red corals have the shape of small leafless bushes and grow up to a meter in height. Their valuable skeleton is composed of inter meshed spicules of hard calcium carbonate colored in shades of red by the pigments of carotenoid.