Blue Coral: A variety of coral thought to be in the first stage of decomposition, since the color usually extends only just below the surface. It is known both as Allopora Subviolacea and Akori. This unusual variety has been found off of Cameroon.
Black Coral: A coral particularly good for carving. Its black color is believed to be coral in an early stage of decay, since the color only persists a little below the surface. Once abundant in the Persian Gulf, a similar type is found in the Mediterranean.
Coral: A hard, calcareous and organic substance that makes up the skeleton of certain polyps, which are small marine invertebrates that live in colonies, usually in reefs.
Fake Coral: Man- or machine-made substitute used to mimic real, organic coral.
Golden Coral: A coral with a resinous or lacquered texture, and found off Maui, in Hawaii.
Precious, or Noble Coral: A type of red coral called Corallium Rubrum, or Corallium Nobile, Precious coral can be found in the Mediterranean, Sardinia and Sicily, as well as in Tunis, Algeria and Morocco.
Red Coral: This is the most valued coral of all, favored worldwide for its hardness, beauty, and sanguine hue. Red Coral is found in a number of places, but its most famous location is the sandy bottom of the Mediterranean, and the Gulf of Naples near Genoa.