Precious coral
Corallium rubrum
Scientific classification
Kingdom: Animalia Phylum: Cnidaria Class: Anthozoa Subclass: Alcyonaria Order: Gorgonacea Family: Coralliidae Genus: Corallium

Precious coral or red coral is the common name given to Corallium rubrum and several related species of marine coral. The distinguishing characteristic of precious corals is their durable and intensely colored red skeleton, which is used for making jewelry. Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Animalia redirects here. ... Classes Anthozoa - Corals and sea anemones Scyphozoa - Jellyfish Staurozoa - Stalked jellyfish Cubozoa - Sea wasps or box jellyfish Polypodiozoa Hydrozoa - Hydroids, hydra-like animals Cnidaria[1] (IPA: [2]) is a phylum containing some 11,000 species of relatively simple animals found exclusively in aquatic, mostly marine, environments. ... Anthozoa is a class within the phylum Cnidaria that contains the sea anemones and corals. ... A sea fan is a form of sessile colonial cnidarian, similar to a sea pen or a soft coral, found in tropical and subtropical seawater. ... Subclasses Alcyonaria Zoantharia See text for orders. ...

Habitat

Red corals grow on rocky seabottom with low sedimentation, typically in dark environments--either in the depths or in dark caverns or crevices. The original species, C. rubrum, is found mainly in the Mediterranean Sea. It grows at depths from 10 to 300 m, although the shallower of these habitats have been largely depleted by harvesting^[1]. The same species is also found at Atlantic sites near the Strait of Gibraltar and at the Cape Verde Islands^[1]. Other Corallium species are native to the western Pacific, notably around Japan (Corallium japonicum) and Taiwan^[2]; these occur at depths of 350 to 1500 m in areas with strong currents^[1]. Composite satellite image of the Mediterranean Sea. ... The Atlantic Ocean is the second-largest ocean, covering approximately one-fifth of the Earths surface. ... The Strait of Gibraltar as seen from space. ... Pacific redirects here. ...

Anatomy

In common with other Gorgonacea, red corals resemble small leafless bushes up to a meter tall. Their valuable skeleton is composed of intermeshed spicules of hard calcium carbonate, colored in shades of red by carotenoid pigments^[1]. In living specimens, the skeletal branches are overlaid with soft bright red integument, from which numerous retractable white polyps protrude^[3]. The polyps exhibit octameric radial symmetry. A sea fan is a form of sessile colonial cnidarian, similar to a sea pen or a soft coral, found in tropical and subtropical seawater. ... Calcium carbonate is a chemical compound, with chemical formula CaCO3. ... Carotenoids are organic pigments that are naturally occurring in plants and some other photosynthetic organisms like algae, some types of fungus and some bacteria. ... In zoology, a polyp is one of two forms of individuals found in many species of cnidarians. ... The elaborate patterns on the wings of butterflies are one example of biological symmetry. ...

Coral as a gemstone

Polished fragments of red coral

Chinese coral sculpture

Coral earrings

The hard skeleton of red coral branches is naturally matte, but can be polished to a glassy shine^[2]. It exhibits a range of warm reddish pink colors from pale pink to deep red; the word coral is also used to name such colors. Owing to its intense and permanent coloration and glossiness, precious coral skeletons have been harvested since antiquity for decorative use. Coral jewelry has been found in ancient Egyptian and prehistoric European burials^[3], and continues to be made to the present day. A womans ear with a large silver earring. ... Categories: Stub | Colors ...

Precious coral has relative density of 3.86 and hardness 3.5 on the Mohs scale^[4]. Due to its softness and opacity, coral is usually cut en cabochon, or used to make beads. Relative density (also known as specific gravity) is a measure of the density of a material. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. ... A cabochon or cabouchon is a gemstone which has been shaped and polished as opposed to facetted. ... Look up bead in Wiktionary, the free dictionary. ...

Trivia

• The two biogenic precious gemstones, coral and pearl, although drastically different in appearance, are chemically very similar. Both are mostly calcium carbonate deposited by marine invertebrates^[2].
• Another unrelated species, the Hawaiian black coral is sometimes used as an ornamental material. Its skeleton is not mineralized, consisting mostly of conchiolin.
• In Vedic astrology red coral is associated with the planet Mars.

Strand of akoya pearls from China Pearl farm, Seram, Indonesia A pearl is a hard, rounded object produced by certain animals, primarily mollusks such as oysters. ... Invertebrate is a term that describes any animal without a spinal column. ... Map of the Hawaiian Islands, a chain of islands that stretches 2,400 km in a northwesterly direction from the southern tip of the Island of Hawai‘i. ... Genera Antipathes Aphanipathes Bathypathes Cirripathes Leiopathes Parantipathes Stichopathes Taxipathes Black coral is a term given to a group of deep water, tree-like tropical coral related to sea anemone. ... Conchiolin (sometimes referred to as conchin) and perlucin are complex proteins which are secreted by a molluscs outer epithelium (the mantle). ... Sri Navaratna - the 9 Gems Navaratna, literally a Sanskrit compound word meaning having nine gems, is a talisman or accessory set with nine gems. ... In Jyotish astrology, Mangala is the name for Mars, the red planet. ...

References

2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the Anno Domini (common) era. ... February 15 is the 46th day of the year in the Gregorian Calendar. ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the Anno Domini (common) era. ... February 15 is the 46th day of the year in the Gregorian Calendar. ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the Anno Domini (common) era. ... February 15 is the 46th day of the year in the Gregorian Calendar. ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the Anno Domini (common) era. ... February 15 is the 46th day of the year in the Gregorian Calendar. ...

External links

• www.arkive.org Photos of living red corals and skeletons (Accessed 02 February 2007)
• International Colored Gemstone Association Extensive info on gemstone coral and jewelry photos (Accessed 02 February 2007)
• American Gem Trade Association Information on coral as a gemstone (Accessed 02 February 2007)
• Organic Gems: Red Coral Jewelry Photos of raw coral material and coral jewelry (Accessed 02 February 2007)