This organic gem material is made of the remains from skeletons of marine animals, which are known as coral polyps. These tiny creatures live in colonies forming branch structures as they develop finally forming coral reefs and atolls. Raw coral looks dull when it is unpolished. After working on it, it gives a vitreous luster. Coral is sensitive to heat and acids and can fade with wear. Though it is found in red, pink, white and blue varieties, red coral is considered to be the most valuable of all. The most precious coral is found in warm waters.

Locations:

The most extensive development of extant coral reef is the Great Barrier Reef off the coast of Queensland, Australia. Indonesia is home to 581 of the world's 793 known coral reef-building coral species. Isolated corals exist even in cold waters, such as off the coast of Norway. Japanese coral is red, pink or white. Other localities for red and pink coral are found on the Mediterranean and African coasts, the Red Sea and the waters off Malaysia and Japan. Golden and black coral is found off the coasts of the West Indies, Australia and the Pacific Islands.

Chemical Composition: Calcium Carbonate
Crystal Structure: Trigonal
Hardness: 3-4
Specific Gravity: 2.68
Refractive Index: 1.49-1.66
Colors: Red, pink, white, blue, golden and black.
Luster: Dull to vitreous

Astrological Relevance:

Coral is considered as one of the birthstones for the zodiac sign of Taurus (April 20 To May 21).