Coral

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Ox blood coral necklace.

Coral is an organic gemstone which is cut from a mass of skeletons, secreted by polyps as a calcareous habitat. These corals, usually, grow at a depth of no more than about 50 feet (15 to 20 meters) in tropical to sub-tropical waters in a belt between 30 degrees above and below the equator. It comes in a wide variety of colors which are caused by both the water temperature, the food and the level of pollution. The highest valued corals are those with a dark red (ox blood) or pinkish (peau d'ange) color. Corals are usually cut as beads or en cabochon. The larger the stones and the more even the color distribution, the higher the price will be. Cameos and sculptures were also carved from this gem. There is an emphases on were as most coral reefs are now, rightfully, protected globally due to their invaluable ecological role. Much like the trade in ivory, the trade in old coral is still acceptable and many coral artifacts are of historic value.

Coral was a favorite gem during the Victorian period and these earrings are a grand example of their use. The large pendeloque drops are suspended from a circular surmount inset with a large rose cut diamond. This coral is most likely from the Mediterranean sea. The gold fittings are 14 karat rosy yellow Victorian gold and the earrings have been later fitted with clip backs to support their heavy weight.
Image courtesy of Lang Antiques
Many cultures have used coral as adornments or for medicinal purposes. Especially the Mediterranean countries as Italy, Morocco, Corsica, Algiers as well as northern European countries used them as talismans and in folklore jewelry. In ancient Rome coral pendants were hung on the necks of infants to warrant them from danger and sickness and when worn on the neck of a woman it could protect against infertility. Other credits given to this gemstone were described by Pliny the Elder and involved the protection against being struck by lightning as well as to still temptresses.

In Chinese cultures coral was credited as prolonging life expectancy and official promotion, while in ancient Greece coral had the attribute of counteracting evil spells, storms, poisons and robbery. The Navajo Indians considered coral as one of the 18 sacred object and many native American jewelry and objects are decorated with this gem.

Red is the color of passion and red coral is a symbol of love and prosperity. It induces creativity, optimism and inner peace. In a metaphysical sense it is used for healing with the concentration on the circulatory system.

The Italian town Torre del Greco at the foot of mount Vesuvius - the volcano that buried Pompeii and Herculaneum - has for centuries been the main center of coral trade and coral cutting.

Buff-cut ox-blood corals inlaid between diamond set platinum channels in an Art Deco ring.
Image courtesy of Lang Antiques


Gemological information for coral
Color Red, orange, pink, peach, black, brown, gold
Crystal Structure Amorphous (organic)
Refractive Index 1.48-1.56
Durability Soft and fragile
Hardness 2.5-4
Similar stones Coral may be mimicked by glass, plastics and ceramics
Treatments Dyeing
Country of origin Generally between the 30 degrees below and above the equator topical to sub-tropical waters
Coral care
Ultrasonic cleaning Not safe
Steam cleaning Not safe
Warm soapy water Not safe, use a damp cloth
Chemical attack Not safe
Light sensitivity Sensitive
Heat sensitivity Not safe

Online G&G articles on coral

Lang Antiques
Lang Antiques