A pearl is a hard, general spherical object produced within the soft tissue (specifically the mantle) of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur. The finest quality natural pearls have been highly valued as gemstones and objects of beauty for many centuries, and because of this, the word pearl has become a metaphor for something very rare, very fine, very admirable, and very valuable.
Valuable pearls occur in the wild, but they are very rare. Cultured or farmed pearls make up the majority of those that are currently sold. Pearls from the sea are valued more highly than freshwater pearls. Imitation or fake pearls are also widely sold in inexpensive jewelry, but the quality of their iridescence is usually very poor - and generally speaking, artificial pearls are easily distinguished from genuine pearls. Pearls have been harvested and cultivated primarily for use in jewelry, but in the past they were also stitched onto lavish clothing. Pearls have also been crushed and used in cosmetics, medicines, or in paint formulations.
Pearls that are considered to be of gemstone quality are almost always nacreous and iridescent, like the interior of the shell that produces them. However, almost all species of shelled mollusks are capable of producing calcareous concretions, creating pearls of lesser shine or less spherical shape. Although these may also be legitimately referred to as "pearls" under U. S. Federal Trade Commission rules, and are formed in the same way, most of them have no value, except as curios.
Valuable pearls occur in the wild, but they are very rare. Cultured or farmed pearls make up the majority of those that are currently sold. Pearls from the sea are valued more highly than freshwater pearls. Imitation or fake pearls are also widely sold in inexpensive jewelry, but the quality of their iridescence is usually very poor - and generally speaking, artificial pearls are easily distinguished from genuine pearls. Pearls have been harvested and cultivated primarily for use in jewelry, but in the past they were also stitched onto lavish clothing. Pearls have also been crushed and used in cosmetics, medicines, or in paint formulations.
Pearls that are considered to be of gemstone quality are almost always nacreous and iridescent, like the interior of the shell that produces them. However, almost all species of shelled mollusks are capable of producing calcareous concretions, creating pearls of lesser shine or less spherical shape. Although these may also be legitimately referred to as "pearls" under U. S. Federal Trade Commission rules, and are formed in the same way, most of them have no value, except as curios.
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