Tuesday, September 13, 2011

Coral Fossils for Jewelry !

Natural Coral Fossil cut as a Pendant

Corals are simple animals that secrete skeletons made of calcium carbonate. They are close relatives of sea anemones and jellyfish and are the main reef builders in modern oceans. Corals can be either colonial or solitary.

As fossils, corals are found worldwide in sedimentary rocks. Based on these fossils, we know that the corals began their long evolutionary history in the Middle Cambrian period, over 510 million years ago. In Kansas, they were deposited from about 315 to 250 million years ago. Nice coral fossils are found in Pennsylvanian and Permian rock formations. Although corals are the main reef builders in modern oceans, not all corals build reefs. In addition to the corals, which are called framework organisms, other organisms contribute to the formation of reefs. For example, modern reefs are inhabited by binding organisms (such as encrusting algae) and filler organisms (such as snails, bivalves, and sponges), whose skeletons fill in the spaces in the reef after death.

Two groups of corals were important inhabitants of the Pennsylvanian and Permian seas--tabulate and rugose corals. Tabulate corals were exclusively colonial and produced calcium carbonate skeletons in a variety of shapes: moundlike, sheetlike, chainlike, or branching. Tabulate corals get their name from horizontal internal partitions known as tabulae. Some tabulate corals were probably reef builders..

Pink Coral Fossil and Indonesian Coral Fossil are among the most commonly found Coral Fossils used in todays jewelry.

Coral fossil material displays the unusual internal structure of the original coral. Coral fossil cuts and polishes like Agate, but in most cases are a bit softer.


Red Eye Coral and Black Eye Coral are two of the more unusual types of Coral Fossil found in present day markets. Both come from sea floors around South East Asia.


Sponge Coral ! That's its trade name. It is known to marine biologists as melithaea ochrace. A sponge coral really has nothing to do with sponges. It just looks like a sponge. Found mainly in the South China Sea, from Taiwan down to Indonesia, the sponge coral has a distinct fan-shaped appearance underwater. Until recently, sponge coral was not used for jewelry as they weren't considered jewelry-quality coral because they contained too many holes. However with the "farming" of man-enhanced Sponge Coral, we now have a renewable source and thus the harvesting and use of other natural corals is becoming more and more controlled, even to the extent that importation of coral is illegal into many countries without special government issued licenses, however Sponge Coral does not fall under these regulations. The majority of Sponge Coral used in jewelry has to date been shades of reds and oranges.

A very rare pure White Coral Fossil.

The coral can be cut and placed into very fine jewelry, such as this Black Coral ring. However, coral is best used in earrings and pendants, as its softness can allow it to be easily damaged in jewelry such as rings, unless properly protected.


And of course in todays market place we have all kinds of fakes and man made gemstones. Although natural, colored coral fossil stones are normally found to have been helped a bit with some colorations from man.