Coral is created of the skeletal remains of tiny marine animals called coral polyps that form branching structures as they grow, eventually forming full coral reefs and atolls. The surface of these branches has a distinctive striped or wood-grain pattern made by the coral polyps. Most corals are made up of calcium carbonate while black and golden corals are made of a hornlike material called conchiolin.
Most coral ranges in colors of red, pink, white, gold, blue and black.
Most coral today is harvested from the Mediterranean Sea or in the Pacific Ocean near Japan and Taiwan. Black coral is a plant that came mostly from Mexico and the Caribbean but is no longer commercially available.