Like Pearls, Corals help make up the very small list of organic jewelry materials. Also, like pearls, Corals consist of more than 90% calcium carbonate. The corals used in bead and jewelry making are not the protected coral species of the fragile coral reefs, but the more common and hearty species such as corallium japonicum or corallium rubrum. Coral is sensitive to heat, direct sunlight and cosmetics. Currently the International Commission of Colored Gemstones (CIBJO) recognizes only five organic (once living material) gemstones: Ammolite, amber, pearl, jet, and coral.