Interesting Facts about Pearls - Formation and Types of Pearls
Pearls are precious, highly valued gems that have a lustrous shine and come in different colors and hues. Pearls are produced by oysters and by other shelled mollusks such as clams and mussels. Pearls start forming when mollusks react to the entry of a foreign particle into their shell.
There are freshwater pearls and saltwater pearls. Freshwater pearls are made by mussels that live in freshwater lakes and rivers. Freshwater pearls come in different shapes and forms. They are naturally white, cream, pink, peach or lavender in color.
Saltwater pearls are made by saltwater clams that are also known as "Pearl Oysters." They are round and have a better shine when compared to freshwater pearls. Saltwater pearls are naturally white, cream, yellowish golden or silver gray in color.
How do pearls form?
The body of the oyster is protected by a shell that is made up of two parts joined by a hinge. The body is separated from the shell by a layer called the "mantle." The mantle secretes a substance called, "nacre" that hardens to form the outer layer of the cell.
The formation of a pearl is initiated when a foreign particle is trapped between the mantle and the innermost layer of the shell. When this happens, the particle irritates the mantle layer. To soothe this irritation, the oyster produces a substance called "nacre" around the foreign particle starting the formation of a pearl.
A pearl is a foreign particle entirely covered with nacre. All pearls are not round. Some pearls have uneven shapes and are known a "baroque" pearls.
Cultured pearls are made by the intervention of humans. To create a cultured pearl, the shell of the oyster is opened, and a small part of the mantle is slit open. A small particle is inserted into the mantle and the innermost layer of the shell. This particle acts as the irritant.
The oyster treats this irritation by secreting nacre around the particle and over time this becomes a cultured pearl. Cultured pearls are not as expensive as natural pearls.
Types of Cultured Pearls
Akoya pearls are truly classic pearls that are round and are almost smooth. They have very few imperfections or no imperfections at all. They have the highest lustre and shine when compared to other pearls. These pearls are white or cream in color.
Tahitian Pearls are grown in the Black-Lipped Oyster. These pearls are black in color and are large ranging from 9 mm–16 mm in size.
Tahitian Pearls come in a wide range of colors such as black, grey, silver, green, blue and purple.
South Sea Pearls
South Sea Pearls are saltwater pearls that are cultivated from the oysters living in the South Seas near Northern Australia and South-East Asia including Myanmar and Indonesia. They produce pearls that are 10 - 20 mm in size and are silver or gold in color. These pearls are the largest of cultivated pearls and the most expensive ones.
Keshi Pearls are rare freshwater pearls and are fully made of nacre. These pearls are not round. These pearls do not have the particle (also referred to as the nucleus of the pearl) that acts as an irritant. Keshi Pearls come in different shapes, sizes, and colors.
In the case of Keshi Pearls the particle (nucleus) that acts as an irritant is pushed out of the mollusk but the pearl formation continues. Due to the absence of a central nucleus, the entire pearl is made of nacre.
Coin pearls have a flat surface just like coins and are freshwater pearls. The flat surface of the pearl allows more light to reflect off the surface of the pearl. This results in the pearl having a greater shine when compared to other pearls.
How to take care of pearls?
Do not keep pearls with other jewellery, store them in a soft cloth pouch.
Do not store pearls in a plastic bags because the chemical in the plastic can discolour the pearls.
Store pearl jewelry on a flat surface.
Do not spray perfumes or deodorants directly over the pearls.
Do not use strong detergents to clean pearls.
Clean pearls with a soft damp cloth to wipe them, use another soft dry cloth to wipe away the moisture.
Do not wear pearls after applying any medicated cream on your skin.
More Facts about Pearls
Pearls are the only gems made by animals during their lifetime.
Harvesting pearls do not kill mollusks.
The nacre layer alone is referred to as the "Mother of Pearl".
All mollusks can make pearls.
Pearls get their color from the shell in which they grow.
Akoya or saltwater pearls are made by oysters and can take five to twenty years to grow.
Freshwater pearls are produced by mussels and can take one to six years to grow.
Every pearl is unique, and all pearls have minor imperfections.
Today mostly all pearls are cultivated.
Pearl farming is known as “Periculture.”
The oldest pearl was found in the sarcophagus of a Persian princess; it is currently displayed in the Louvre Museum in Paris.
Legends state that Cleopatra dissolved a pearl in wine and drank it to prove her love for Marc Antony.