Coral

Coral,or corals are marine organisms in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps." The group includes the important reef builders that inhabit tropical oceans, which secrete calcium carbonate to form a hard skeleton. Coral's many colors give it appeal for necklaces and other jewelry. Intensely red coral is prized as a gemstone. It is sometimes called fire coral, but is not the same as fire coral. Red coral is very rare because of overharvesting due to the great demand for perfect specimens.