Coral is an organic gemstone.
It is created by a biological process instead of being created with various minerals or mysterious elements coming together deep within the Earth.
Tiny coral polyps, with their hard exoskeletons, grow on top of each other for generations. Eventually, larger structures are formed. This process happens very slowly. Often, the formations grow only 1 mm per year.
The coral used in jewelry, with the exception of Blue Coral, is not the same as the coral composing coral reefs.
The coral used in jewelry is either Precious Coral or Semiprecious Coral.
Both grow in deep, 500 to 1,000 feet, waters.
Precious Corals are colorful, less porous, harder, more lustrous, and are harder to obtain.
Precious Corals include:
Pink Coral - Angel Skin Coral falls into this group.
Gold Coral - This coral is rare but it can be found in Alaska or Hawaii.
Semiprecious Corals include:
Blue Coral - Blue Coral is the only coral used in jewelry that is a reef building coral that was not grown in deep waters.
Many of the other types of coral of which you may have heard are usually the same corals listed above with a dye or treatment applied.
Fossilized Coral is also referred to as "Agatized Fossil Coral" because during formation, the coral remains are replaced with Agate. These Corals are usually found inland; in places where oceans once existed.
Genuine coral is rare due to both over harvesting in the past and its extremely slow growth process.
Most of the coral beads available today are made from bamboo coral found in the Philippines. Bamboo coral is naturally gray. After being shaped into a bead or a cabochon, the coral is either dipped in red dye or injected with it to spread the color through the entire piece.
It is then coated with resin and polished.
While this coral is legal to harvest and sell, many countries have laws limiting or restricting harvesting and ownership of the coral found there.
So before you go on that lovely vacation, intent on bringing home some native coral, do your research! Even if the type of coral with which you have fallen in love is legal to purchase where you are, it may not be legal to bring it back to the United States.
For more information, please check out the sources I used below: