Coral: star of the sea

Coral is a stone of organic origin, composed almost wholly of calcium carbonate with about three per cent magnesium carbonate and possibly a trace of iron oxide. It is generally expressed as being the axial skeleton of coral polyps.

These polyps are minute, living creatures that reside in vast colonies. When they die, their skeletal remains build up to form massive coral reefs. Coral occurs in a variety of colours, though is most commonly found in shades of red or pink.

The cause of such rosy hues has never been fully discovered, hence the speculation that iron is present. There are three other varieties of coral: black coral (Antipathes Spiralis), a blue variety (Allopara Subirolcea) and a white variety (Oculinacea).

The most prized variety from a gemmological perspective is the branch-like material named Corallium Rubrum, Corallium Nobile, or more commonly, precious coral. It is harvested by dragging the seabed among the coral reefs with a frame that snaps off coral branches and scoops them into a net.

Precious coral is chiefly fished from the warm waters of the Mediterranean Sea.

Other areas where the mineral can be found include the coasts of Greece and its islands, the Canary Islands, the Malaysian Archipelago, the Red Sea and Northern Australia.

The beauty of coral and its resulting popularity has led to heavily depleted reefs badly in need of regeneration. As a result, a ban currently exists on the export of coral products from Australian waters.

While coral derives its name from the Greek word korallion, it’s a lesser known fact that it is also referred to as Gorgeia. The name – used over the centuries and still in circulation today among Greek fishermen – comes from the myth that branches near the Greek seashore were dripped in blood from the head of Medea. These branches were planted in the sea as the coral we know.

Coral inlays and ornaments have been found in Celtic tombs dating back to the Iron Age and it is also one of the seven treasures in Buddhist scriptures, and prominent in Tibetan rosaries. In addition to its religious significance, coral was long thought to be a powerful talisman that could stop bleeding, protect the bearer from evil spirits and ward off hurricanes.

Recently, coral’s healing properties have been associated mostly with women, young children and the elderly and it is believed to increase fertility, regulate menstruation, assist in teething and arthritis and to prevent epilepsy.

Red coral attracts love and prosperity, and is considered a stone of passion. Emotionally, it brings inner peace, strength, and understanding of purpose.

Today, coral is commonly fashioned into beads, small-carved objects and cameos. People of India and China favour the material for ornamental and ritual purposes and it is often combined with turquoise by the Arabians and North Africans.

Because of its fragility – the gem registers 3.5-4 on Moh’s scale – coral should be protected from scratches, sharp blows and significant changes in temperature, and any cleaning or repair must be done with great care, avoiding acid preparations and detergents.

fact sheet

Hardness: 3.5-4
Variety of:
Calcium Carbonate
Found: Mediterranean Sea, Greece and surrounding islands, Canary Islands, Tunisia, Morocco, Algeria, Malaysian Archipelago, Japan, Red Sea and Australia