noble coral , or red coral , is the common name given to the genus of coral, Corallium . The distinguishing characteristic of valuable corals is the long-lasting and highly colored red or orange-orange skeleton used for jewelry making.
Video Precious coral
Habitat
Red corals grow in rocky seabottom with low sedimentation, usually in dark environments - either in depth or in dark caves or crevices. The original species, C. rubrum (formerly Gorgonia nobilis ), is found mainly in the Mediterranean Sea. It grows at a depth from 10 to 300 meters below sea level, although the shallowest of this habitat has been largely spent with the harvest. In Alghero's underwater cave, Sardinia ("Coral Riviera") grows in depths from 4 to 35 meters. The same species are also found on Atlantic sites near the Strait of Gibraltar, in the Cape Verde Islands and off the coast of Southern Portugal. Other corallium species originate from the western Pacific, especially around Japan and Taiwan; this occurs at depths of 350 to 1500 meters below sea level in areas with strong currents.
Maps Precious coral
Anatomy
Similar to others Alcyonacea , the red coral has the shape of a small leafy shrub and grows to one meter in height. Their valuable skeleton consists of a hard intersenhed calcium carbonate spicula, colored in shades of red by carotenoid pigments. In live specimens, the skeletal branch is coated with a soft, soft red integument from which many white polyps can be drawn in. Polyps show the radial symmetry of the ocmera.
Species
The following are species known in the genus:
As a gemstones
The hard coral framework of the red coral is naturally matte, but can be polished to become like glass. It shows various warm reddish colors from pale pink to deep red; the coral is also used to name those colors. Due to strong and permanent color and luster, valuable coral skeletons have been harvested since ancient times for decorative use. Coral jewelry has been found in ancient Egyptian cemeteries and European prehistory, and continues to be done to this day. It was very popular during Victorian times.
The noble reef has a relative density of 3.86 and 3.5 hardness on the Mohs scale. Due to their softness and elasticity, coral is usually cut into cabochon, or used to make beads.
Trade history
At the beginning of the first millennium, there is significant coral trade between the Mediterranean and India, where it is very valuable as a substance believed to be endowed with a mysterious sacred nature. Pliny the Elder states that, before the great demand of India, the Gauls used it for their armor and helmet; but in this period, so much in demand of the East, which is rarely seen even in the regions that produce it. Among the Romans, coral branches hung around the necks of the children to protect them from harm from the outside, and the substance has many of the medicinal benefits attributed to it. The belief in the potential of corals as a charm continued throughout the Middle Ages and early 20th century Italy was used as protection from evil eyes, and by women as a remedy for infertility.
From the Middle Ages onwards, securing the rights to reef fisheries off the coast of Africa was a considerable object of competition among Mediterranean communities in Europe. The story of Torre del Greco is so intertwined with corals that it forms an inseparable pair, and is documented as early as the 15th century. In 1790 the Royal Society of Coral was established in the town of Torre del Greco, with the idea of ​​working and selling reef fish. This shows that for years reef fishing in this city. It also came into force on December 22, 1789, by Ferdinand IV of the Bourbon Code (prepared by Neapolitan jurist Michael Florio), with the intent to arrange for reef fishes in the years that starred, alongside sailors Torre del Greco, people in Trapani This rule does not have the expected success. From 1805, when he founded the first reef-making plant at Torre del Greco (by Paul Bartholomew Martin, but with Geno's French origin), the golden age for reef-making in the city on the slopes of Vesuvius began, As it cooperated with more and more coral reef fishing under the control of the fisherman Torre del Greco. Since 1875, Torre del Greco began working with the Sciacca coral and reef-building school built in 1878 in the city (which closed in 1885 to reopen in 1887), which in 1933 established a coral museum. Then comes the processing of Japanese corals found in the Madras and Calcutta markets. Another story is not a short period of Tunisian fisheries secured by Charles V for Spain; but the monopoly soon fell into the hands of France, which held the right until the government of the Revolution in 1793 opened open trade. For a short period (about 1806) the British government controlled the fisheries, but this was later returned to the French government. Before the French Revolution much of the coral trade was concentrated in Marseille, but later largely moved to Italy, where the procurement of raw materials and work was centered in Naples, Rome, and Genoa.
In culture
The origin of corals is described in Greek mythology by the story of Perseus. After petrifying Cetus, a sea monster threatening Andromeda, Perseus places Medusa's head on the riverbank while washing his hands. When he finds his head, he sees that his blood has changed the seaweed (in some variant of the reed) into a red coral. So, the Greek word for coral is 'Gorgeia', because Medusa is one of the three Gorgons.
Poseidon lived in a palace made of rocks and gems, and Hephaestus first created his work from corals.
The Romans believed that corals could protect children from harm, as well as heal the wounds made by snakes and scorpions and diagnose diseases by changing colors.
- In Hindu red coral astrology is associated with Mars or Graha-Mangala planet and is used to please Mars. It should be worn on the ring finger.
- A red coral branch stands out in the city coat of Alghero, Italy.
- In Islam, corals are referred to as one of the gems in heaven.
Preservation
Intensive fisheries, especially in shallow water, have damaged this species along the Mediterranean coastline, where colonies in depths less than 50 meters are greatly reduced. Fisheries and now climate change threaten their persistence. The three oldest Mediterranean preservation zones - Banyuls, Carry-le-Rouet and Scandola, off the island of Corsica - all have a substantial population of C. rubrum . Since protection is established, the colony grows in size and amount at shallow depth and deeper.
See also
- Coral Jewelery Museum
- Black coral; also sometimes used as an ornamental material
- Amber
- Pearls
References
External links
- Red coral media in ARKive
- International Colored Gems Association Extensive information about gemstones and gemstone jewelry photos
- The American Gem Trade Association Information about corals as gems
- Red Mediterranean Coral: International Research Team research team on Mediterranean red coral (Retrieved 15 March 2007)
- Corallium rubrum, Food and Agriculture Organization of the United Nations
Source of the article : Wikipedia
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