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.
Kokichi Mikimoto was a Japanese entrepreneur who is credited with creating the first cultured pearl and subsequently starting the cultured pearl industry with the establishment of his luxury pearl company Mikimoto.
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.
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.
Rangiroa or Te Kokōta is the largest atoll in the Tuamotus and one of the largest in the world.
The freshwater pearl mussel is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae.
Unionida is a monophyletic order of freshwater mussels, aquatic bivalve molluscs. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels. The most common families are the Unionidae and the Margaritiferidae. All have in common a larval stage that is temporarily parasitic on fish, nacreous shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment.
Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels. These pearls are produced in Japan and the United States on a limited scale, but are now almost exclusively produced in China. The U.S. Federal Trade Commission requires that farmed freshwater pearls be referred to as "freshwater cultured pearls" in commerce. Quality of cultured freshwater pearls is evaluated through a grading system of a series of A values, based on luster, shape, surface, colour and matching.
Aquaculture in Australia is the country's fastest-growing primary industry, accounting for 34% of the total gross value of production of seafood. 10 species of fish are farmed in Australia, and production is dominated by southern bluefin tuna, Atlantic salmon and barramundi. Mud crabs have also been cultivated in Australia for many years, sometimes leading to over-exploitation. Traditionally, this aquaculture was limited to table oysters and pearls, but since the early 1970s, there has been significant research and commercial development of other forms of aquaculture, including finfish, crustaceans, and molluscs.
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.
Keshi pearls are small non-nucleated pearls typically formed as by-products of pearl cultivation. A Japanese word also meaning "poppy", it is used in Japanese for all pearls that grew without a nucleus. Originally, keshi pearls referred to those pearls formed when a bead nucleus was rejected. More recently, keshi has been used to refer to second harvest pearls and even to freshwater non-nucleated pearls. However the later usage referring to freshwater pearls is considered erroneous by many leading gem trade associations. Because they have no nucleus, keshi pearls are composed entirely of nacre.
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.
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.
Imitation pearls are man-made faux pearls. They are not to be confused with cultured pearls, which are real pearls created through human intervention.
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.
Pinctada margaritifera, commonly known as the black-lip pearl oyster, is a species of pearl oyster, a saltwater mollusk, a marine bivalve mollusk in the family Pteriidae. This species is common in the Indo-Pacific within tropical coral reefs.
The Abernethy pearl, also known as the Little Willie pearl, is a 43.60-grain (2.825 g) freshwater pearl named after William Abernethy (1925–2021), who discovered it in Perth, Scotland, in the River Tay in 1967. It is also known as Bill's pearl.
