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The GIA and CIBJO now simply use the term 'pearl' (or, where appropriate, the more descriptive term 'non-nacreous pearl') when referring to such items, rather than the previously-used term 'calcareous concretion' [6] [7] and, under Federal Trade Commission rules, various mollusc pearls may be referred to as 'pearls' without any qualification. [8]
The freshwater pearl mussel (Margaritifera margaritifera) is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae.. Although the name "freshwater pearl mussel" is often used for this species, other freshwater mussel species (e.g. Margaritifera auricularia) can also create pearls and some can also be used as a source of mother of pearl.
Most molluscs with shells can produce pearls, but only the pearls of bivalves and some gastropods, whose shells are lined with nacre, are valuable. [ 4 ] [ 5 ] The best natural pearls are produced by marine pearl oysters , Pinctada margaritifera and Pinctada mertensi , which live in the tropical and subtropical waters of the Pacific Ocean .
Melo is a genus of extremely large sea snails, marine gastropod molluscs in the family Volutidae, the volutes.Because of their huge ovate shells, these snails are often known as "bailers" (the shells were sometimes used for bailing out canoes) or "melons" (because the shell resembles that fruit).
Mollusca is a phylum of protostomic ... A 50-second video of snails ... 300–343, 367–403 The best natural pearls are produced by marine pearl ...
These bivalve mollusks were heavily exploited for freshwater pearls, and for their nacre which was used in the button manufacturing industry in the late 19th and early 20th centuries. The effects of heavy fishing for freshwater mussels in North America in for use in manufacturing buttons put many of these species close to extinction.
Pinctada mazatlanica is a species of tropical marine bivalve mollusc 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.
Black South Sea pearls, or Tahitian pearls come from the black-lip oyster; gold and silver South Sea pearls from the gold-lip and silver-lip oysters; and Akoya cultured pearls from Pinctada fucata martensii, the Akoya pearl oyster. Pearls are also obtained in commercial quantities from some species of the closely related winged oyster genus Pteria.