CaCO3 - Calcium Carbonate
Coral is created by sea life. It is the skeletal remains of coral polyps. Coral is calcium carbonate with a trade of carotene. Its color ranges from white to red. Red, pink, and white coral is mostly calcium carbonate. Black and golden coral is conchiolin. It is beautiful in rings, necklaces, and pendants. More on...
Coral is the outside skeleton of tiny ocean animals called polyps, which live in colonies attached to hard underwater surfaces. When alive, polyps combine their own carbon dioxide with the lime in warm seawater to form a limestone-like hard surface, or coral.
Agatized coral occurs when silica in the ocean water hardens, replacing the limy corals with a form of quartz mineral known as chalcedony. This long fossilization process (2030 million years) results in the formation of a "pseudomorph," meaning that one mineral has replaced another without having lost its original form. In 1979 agatized coral was designated the official state stone.
Agatized coral is found in three main Florida locations: Tampa Bay, the Econfina River, and the Withlacoochee/Suwannee River beds.
Black coral was adopted as Hawaii's official state gem on April 22, 1987. The black coral which grows in Hawaii's offshore waters has been established as the official state gem.
Since its discovery by early Hawaiian divers, harvesting of the spectacular corals has led to the establishment of a thriving black coral jewelry industry and enhanced visitor and resident appreciation of Hawaii's ocean resources.
Hawaii's state gem was promoted by scuba divers, perhaps supported by the local jewelry trade. Surprisingly, the Department of Land and Natural Resources testified in favor of its adoption.
Care and Treatment
Coral is especially fragile. Protect coral from scratches and sharp blows. Also avoid large temperature changes (such as leaving it be a heater vent or in a hot car). Do not clean coral in a home ultrasonic cleaner.
Coral is often imitated by plastic, glass, porcelain, and stained bone. Natural coral has a distinctive wood grain texture which can help identify it as the real thing.
Coral has a hardness of 3.5.
Specific Gravity: 2.6 - 2.7
Coral is found on the African coasts, Australia, Japan, Mediterranean coasts, Malaysia, and the West Indies.
Star Stone Months
Coral is said to protect children. In many countries, coral is given as a gift to children.
Coral is one of the seven treasures in Buddhist scriptures.
Coral was long thought to be a strong talisman against bleeding, evil spirits, and hurricanes.
Coral is said to cure madness and give wisdom.
Black Coral is Hawaii's US State Gemstone