Types of Pearls and their largest producers

– a saltwater bivalve mollusc, is the largest pearl producer ("pearl oysters"). The largest quantity of pearls is cultured by molluscs of the Pinctada and Pteria genera.

– gastropod mollusc in the family Haliotidae (class Gastrodopus). Moluscs of this family have a nacre with a bright luster. Other specific names are "Abalone" in English and "Morskoe yshko" (Sea ears) in Russian. Sometimes the name Haliotis or Abalone is used in reference to the family, since it includes one currently living genus. There are 51 species in the genus Haliotis. And there is only one species in Russia - Haliotis discus Reeve, 1846. Three species of the genus Haliotis (Haliotis iris, Haliotis australis, Haliotis virginea) for the bright mother-of-pearl luster are called "sea opal", but they are better known as "paia" or "avabi". All the species of the genus Haliotis have a thick layer of nacre with a bright luster. The natural distribution area is from the moderate environment to the tropical zone of the Pacific, Atlantic and Indian oceans in the rocky bottom zones. The habitat of this species is at depth of the first tens of meter.
The largest shells of the Haliots reach 35 cm in size, but there are shells 5-12 cm in size. The mother of pearl Haliotis is used to make souvenirs and jewelry and the flesh of abalones is widely considered to be a desirable food, and is consumed raw or cooked by a variety of cultures as a delicacy. For molluscs of the genus Haliotis, the most pearl formations in the form of outgrowths on the shell are the pearl blister, but there are also individual pearls of the baroque shape. Now successful attempts are being made to farm individual pearls. This pearl gets the trade name "Abalone pearls".

– the gastropod mollusk in the family Turbinidae (class Gastropos). The molluscs in the family have a shell with a thick layer of nacre. The curved shell reaches up to 25 cm in height. The shell itself is used as souvenirs and for getting nacre; the flesh of mollusc is used as a delicacy product. Molluscs of this genera have a wide geographic distribution area - from polar to tropical latitudes, but the largest number of species, including the largest in size, are native to tropical latitudes. The geoecological area is from the littoral to the sublittoral.
The shell of Turbo marmoratus, which is a part of the genus Turbo is the most widespread in the production of jewelry and handicrafts.

– The only one of the cephalopods that has an external shell, formed due to the mantle secretion. The shell size of the mollusc is from 10 to 27 cm. The habitat of this species is the tropical waters of the Indo-Pacific region, at depths of 50 to 550 m, the floating form. The natural distribution area is from the Andaman Islands and the coastal waters of southern China to the New Guinea and northern Australia. Pearls produced by the molluscs are extremely rare. This pearl gets the trade name "Yellow pearls". Nautilus nacre is the most widespread in jewelry and handicrafts. Original jewelry inserts/accessories are made from the shell of the Nautilus, called "pearl shells" ("Coque de perle"). Such a product is made from separate curved fragments of the polished shell of the Nautilus, which are glued together in a single unit, resembling an oval or egg-shaped pearl or semipearl.

– a freshwater bivalve molluscs in the order Unionoida, known as freshwater pearls. These molluscs are very widespread in various freshwater rivers, but they are restricted exclusively to freshwater rivers, streams, fast flowing freshwater creeks.

– a family of freshwater bivalve molluscs in the order Unionoida, the largest in the order and known as river mussels. The largest of the genus vary in size up to 30 cm. Freshwater mussels occupy a wide range of habitats, but most often occupy lotic waters, i.e. flowing water such as rivers, streams and creeks.

– a family of saltwater and freshwater bivalve molluscs from the Veneroida order. Widely used for food. Shells of these molluscs are deprived of nacre. Beads made of the thick-walled shells of some species are used for the production of cultured pearls. Some species is capable to produce a non-nacreous pearl that is called "Quahog's pearls".

– a family of saltwater and freshwater bivalve molluscs from the Veneroida order. Shells of these molluscs are deprived of nacre. Widely used for food. Some species is capable to produce pearls.

– a family of saltwater and freshwater bivalve molluscs in the Mytiloida order. Shells of these mollusks are deprived of nacre. This species is capable to produce pearls. They are used as a food product. Shells are also processed as a decorative material or food supplements.

– a family of saltwater and freshwater bivalve molluscs in the Pectinoida order. The shells have a thin but highly nacreous inner layer in the part of the shell near the umbos (the pointed end). The maximum size of the shell is 90 cm. The habitat of this species is the littoral and sublittoral zone of saltwater with various bottom substrate, mainly from temperate to tropical latitudes. They have been utilized in the manufacture of clothing for many centuries: gloves, shawls, stockings and cloaks as producers of "sea silk" and as a food product, also known as pearl producers. Pearls, as a rule, are non-nacreous, but species with nacre are also found. The color of the pearl is silvery-gray, black, and brown to reddish, sometimes to red. Such pearls have the trade name "Pen pearls", as these bivalve molluscs were sometimes called. Often pearls are fractured. Species included: Pinna, Atrina and Streptopinna.

– a family of saltwater and freshwater bivalve molluscs (the so-called "scallops") in the Pectinoida order. Shells of these mollusks are deprived of nacre. Molluscs of this family has ability to swim in the water by creating a propulsive jet with a sharp and frequent clapping their valves together. They have been utilized as a delicacy food product. Shape of Pectinidae shell is unequal with distinguishing "ears". They are capable to produce pearls, which is referred to as "Scallop pearls". Pearls of "sea scallops" occur in a range of hues, but pearls of the Atlantic Ocean occur in a wider range from gray, brown, reddish, purple, violet, yellow, orange, cream, pink, red, white, often with the appearance of spotting; Pacific oceanic pearls are painted in white, gray, brown, with cream and yellowish shades. The described variety of pearls is most associated with a voluminous aventurescence shine, although there are also "porcellaneous" pearls. The shape, as a rule, is symmetrical (drop-shaped, "button", oval) and baroque, round varieties are rare. Pearls range in size up to 5 mm, but pearls of round shape with the size bigger than 10 mm are rare, and baroque sizes up to 20 mm are rare. Habitat conditions range from polar to tropical latitudes in the littoral geoecological zone (from 25 to 200 m.) On cottong and low-saline soils, although there are known cases of catching scallops at depths of about 8,000 m. Sea scallops are widespread throughout the oceanic area in areas with water temperature not higher than 20ºС, but the main commercial species producing pearls, suitable for jewelry purposes, it is customary to subdivide into Pacific and Atlantic species.

– a family of saltwater and freshwater bivalve molluscs (the so-called "scallops") in the Pectinoida order. The shells of these molluscs are valued for their translucent color that have been utilized as window decoration. The shells were originally used in glazing, but nowadays they are mainly used in handimade, as a food product and for the paint manufacturing. They are capable to produce pearls. Pearls of gray color with different hues (sometimes to reddish-black), with a high grade of transparency, have a high grade of brilliance and a shape close to spherical. This pearl is known under the trade name "Pearl of the Kapis" ("Kapis pearl" - according to the Filipino mollusc name) or "Pearl Pluckers". The composition of pearls is similar to mother-of-pearl (aragonite, calcite, conchiolin), but it is not so in the strict sense of the word, since it differs structurally from it.

– a family of saltwater gastropods of predacious molluscs in the order Littorinimorpha (Gastropod class). The natural distribution area is the tropical and temperate seas from the intertidal zone sea. The habitat of this species is the littoral and sublittoral zones (at depths of 100 m and more), with silty or sandy bottom substrate.

– a family of saltwater gastropods of predacious molluscs in the order Neogastropoda (Gastopoda order). The natural distribution area is the saltwaters of temperate and tropical latitudes. The habitat of this species is the littoral and sublittoral zones (to depths of 500 m), with hard (rocky or coral), and sand (with minor siltation) bottom substrate.

– a family of saltwater bivalve molluscs in the order Littorinimorpha (Gastropod class). The natural distribution area is the saltwaters of temperate and tropical latitudes (mainly). The representatives of the family were most widely distributed in the western part of the Pacific Ocean and in the eastern part of the Indian Ocean. The habitat of this species is the littoral and sublittoral zones (at depths of the first tens of meters), with hard (rocky or coral), and sandy (with minor siltation) bottom substrate.

– a family of saltwater gastropods of predacious molluscs in the order Neogastropoda (Gastopoda order). Molluscs in this family are native to all climatic zones of the ocean in the littoral and sublittoral geo-ecological zones (from 0.5 to 200 m). The size of the shell ranged from 1 to 50 cm.