Biser

Composition

A pearl is composed of calcium carbonate, mainly aragonite or a mixture of aragonite and calcite, in a crystalline form deposited in concentric layers. The combination of aragonite and conchiolin is called nacre, which makes up mother-of-pearl. Conchiolin is a fibrous protein. Nacre is composed of hexagonal platelets, called tablets, of aragonite, 10-20 μm wide and 0.5 μm thick, arranged in continuous parallel lamina. Nacre appears iridescent because the thickness of the aragonite platelets is close to the wavelength of visible light. The thinner and more numerous the layers in the pearl, the finer the luster.

Formation

Nacreous pearls, the best-known and most commercially significant, are primarily produced by two groups of molluskan bivalves or clams. Natural pearls are nearly 100% calcium carbonate and conchiolin. A pearl is formed when the mantle tissue of a mollusk is injured by a parasite, an attack of a fish, or another event. In response, the mantle tissue secretes nacre into the pearl sac, a cyst that forms during the healing process. This secretion process is repeated many times, thus producing a pearl. Saltwater pearls can grow in several species of marine pearl oysters, and freshwater pearls grow within certain species of freshwater mussels.

Cultured and imitation pearls

Over 95% of the pearls available on the market are cultured pearls. The nucleus bead in a beaded cultured pearl is generally a polished sphere made from freshwater mussel shell. Some imitation pearls are simply made of mother-of-pearl, coral, or conch shell, while others are made from glass and are coated with a solution containing fish scales called essence d'Orient.

Aquatic notes

In perfumery, the aquatic, oceanic and ozonic category is a clean smell reminiscent of the ocean. Aquatic fragrances generally contain calone, a synthetic discovered in 1966, or more recent synthetics such as Floralozone, Helional or even Ambroxan. In Michael Edwards's fragrance wheel, the Fresh family includes a Water subfamily, exemplified by marine and aquatic notes.

Explore all seven extraits in the Discovery Set.

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Related: Aqual · Aquozone · Calone · Calone 1951 · Coral Limestone · Crustaceans · Diving Suit · Fish