A pearl is a hard, glistening object produced within the soft tissue of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, pearl has become a metaphor for something rare, fine, admirable and valuable.
A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism that lives in the sea. Most seashells are made by mollusks, such as snails, clams, and oysters to protect their soft insides. Empty seashells are often found washed up on beaches by beachcombers. The shells are empty because the animal has died and the soft parts have decomposed or been eaten by another organism.
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not all oysters, are in the superfamily Ostreoidea.
Bivalvia, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. The class includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. Shipworms bore into wood, clay, or stone and live inside these substances.
Pinctada is a genus of saltwater oysters, marine bivalve mollusks in the family Pteriidae. These pearl oysters have a strong inner shell layer composed of nacre, also known as "mother of pearl".
Cultured pearls are pearls which are formed within a cultured pearl sac with human intervention in the interior of productive living molluscs in a variety of conditions depending upon the mollusc and the goals. Having the same material as natural pearls, cultured pearls can be cultivated in seawater or freshwater bodies. Over 95% of the pearls available on the market are cultured pearls.
Oyster farming is an aquaculture practice in which oysters are bred and raised mainly for their pearls, shells and inner organ tissue, which is eaten. Oyster farming was practiced by the ancient Romans as early as the 1st century BC on the Italian peninsula and later in Britain for export to Rome. The French oyster industry has relied on aquacultured oysters since the late 18th century.
Pteriidae, also called the feather oysters, is a family of medium-sized to large saltwater oysters. They are pearl oysters, marine bivalve mollusks in the order Pteriida.
Placunidae, also known as windowpane oysters, windowpane shells, and Capiz shells, are a taxonomic family of saltwater clams, marine bivalve mollusks which are related to oysters and scallops.
Pinctada albina is a species of pearl oyster of the genus Pinctada, known as the Shark Bay shell. Another common name is the Arafura shell, endemic to Arafura Sea in Indonesia. It is called the "Amami gai" in Japan.
The Tahitian pearl is an organic gem formed from the black lip oyster. These pearls derive their name from the fact that they are primarily cultivated around the islands of French Polynesia, around Tahiti.
Linatella caudata, common name : the Girdled triton or Poulsen's Triton, is a species of predatory sea snail, a marine gastropod mollusk in the family Cymatiidae.
Pinctada maxima is a species of pearl oyster, a marine bivalve mollusk in the family Pteriidae, the pearl oysters. There are two different color varieties: the Gold-lipped oyster and the Silver-lipped oyster. These bivalves are the largest pearl oysters in the world. They have a very strong inner shell layer composed of nacre, also known as "mother of pearl" and are important to the cultured pearl industry as they are cultivated to produce South Sea pearls.
Pinctada radiata, commonly known as the Atlantic pearl-oyster or the Gulf pearl oyster is a species of pearl oyster distributed throughout the Indo-Pacific and in the Mediterranean. Its range extends as far north as Japan and as far south as the Australian state of Victoria.
Pteria colymbus, the Atlantic winged oyster, is a species of bivalve mollusc in the family Pteriidae. It can be found along the Atlantic coast of North America, ranging from North Carolina to Bermuda and Brazil.
Pteria sterna, or commonly known as the rainbow-lipped pearl oyster or the Pacific wing-oyster, is a species of marine bivalve mollusk in the family Pteriidae, the pearl oysters. This oyster can be found in shallow water along the tropical and subtropical Pacific coast of America, its range including Baja California, Mexico and northern Peru.
Pinctada mazatlanica is a species of tropical marine bivalve mollusk in the family Pteriidae, the pearl oysters. It is known by the English common names pearl oyster, Mazatlan pearl oyster, and Panama pearl oyster. Spanish common names include madre perla, and ostra perlifera panameña. This mollusc was first described to science in 1856 by conchologist Sylvannus Charles Thorp Hanley. Pinctada mazatlanica produces gem-quality pearls and was the basis of a pearling industry in the Gulf of California for centuries.
Pinctada fucata, the Akoya pearl oyster (阿古屋貝), is a species of marine bivalve mollusk in the family Pteriidae, the pearl oysters. Some authorities classify this oyster as Pinctada fucata martensii. It is native to shallow waters in the Indo-Pacific region and is used in the culture of pearls.
Pteria penguin, commonly known as the penguin's wing oyster, is a species of marine bivalve mollusk in the family Pteriidae, the pearl oysters. It is native to the western and central Indo-Pacific region and is used for the production of cultured pearls. The generic name comes from Greek πτερον (pteron) meaning wing.
Pinctada longisquamosa, sometimes called scaly pearl osters, are a small species of pearl oyster found in the western Atlantic. They are distinguished by unique prismatic shell structures which protrude from the outer shell.
