Coral has been popular for use in jewelry designs and other ornamental purposes for a long time now. This popularity can be largely attributed to the brilliant colors of the gem, and the somewhat unusal nature of its origin. Coral is found in relatively shallow and warm waters in the Mediterranean, and off the coasts of Japan and Taiwan. It must be harvested manually, and divers dive to great depths to retrieve this gem. On the surface, the coral specimens are sorted based on size, color and quality. Larger flawless specimens are rare and quite expensive. They are therefore used in high-end jewelry designs that fetch a high asking price on the open market. The remainder of the harvest is used for fashion jewelry applications. These pieces of coral are usually soft and must be stabilized with epoxy resin to harden them before they can be cut and polished and set in silver or other metals to complete the piece. On occasion, a dye is added to the epoxy in order to enhance the color of the specimen. Corals can be found in a wide range of colors. However, only red, pink, orange and black corals are typically used in fashion jewelry applications. Black coral is quite valuable and was harvested off the Mexican cost. In recent times, divers have been unable to find large quantities of black coral, leading environmentalists to raise the alarm about the destruction and possible extinction of some species of coral.
In order to understand these concerns, it is useful to first obtain a basic understanding on the formation of coral. Corals are formed from the skeletal remains of a sea polyp - a tiny creature that dwells in the seas and feeds on plankton. The remains are calcified and added to the coral reef with time. Over a period of decades, the coral reef can grow to a large size, and individual stems can be as large as 2 inches in diameter. However, coral is also very sensitive to the ambient conditions, and change in sea water chemistry, light penetration and temperature can have devastating impacts on coral reefs. Over harvesting of coral for jewelry and ornamental applications combined with the gradual changes in the environmental conditions have caused coral reefs around the world to shrink, and the virtual extinction of some species. Although some countries have promised to curb the harvesting and trade in some species of coral, the lure of financial wealth has meant that enforcement is lax. It remains to be seen if the beauty of this gem also leads to its downfall.