The Formation of Pearls
A mollusk will make a pearl when an irritant becomes lodged inside its shell. Because of overfishing, pollution and drilling for oil, pearls rarely are found in the wild. Today, most pearls are cultured from seawater oysters or freshwater mussels. Does this Spark an idea?
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Process
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When an irritant becomes lodged inside a mollusk, the mollusk begins to coat it with nacre, the same substance it uses to make its shell, to protect itself. A pearl is formed after the mollusk has produced several layers of nacre.
Nacre
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Nacre is made of calcium-carbonate crystals that align with each other, creating a beautiful, natural luster on the surface of the pearl.
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Wild Pearls
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According to americanpearl.com, wild and cultured pearls are identical. The difference is how they are produced. Wild pearls occur naturally when a piece of coral, shell or bone gets stuck inside the mollusk.
Cultured Pearls
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An irritant is purposely introduced to force an oyster or mussel to produce a cultured pearl, according to thepearlmarket.com. In a process called nucleating, pearl farmers graft a small shell bead from a freshwater mussel into a seawater oyster. They introduce a small piece of mantel tissue into a mussel to cause a pearl to form.
Harvesting
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About half of the millions of mollusks seeded every year produce marketable pearls, according to thepearlmarket.com.
Color
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A pearl's color is unpredictable but can be influenced by the mollusk breed, its diet and the water temperature.
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References
- Photo Credit pearl necklace2 image by jcpjr from Fotolia.com
