NATURAL PEARL( MOTI)
A Pearl is a hard object produced within the soft tissue of a living shelled mollusk. Basically it is a concentrated form of calcium carbonate deposits in minute crystalline form in peculiar concentric circles. Ideally, natural pearls are spherical and smooth. Natural pearls are extremely rare available in the wild. Cultured or farmed pearls obtained from pearl oysters are nowadays more commonly in use .
There are two types of pearls naturally occurring which are exotic and cultured which are cultivated by human intervention.
Natural pearls are mostly found in seas of Bahrain. Even there is major occurrence of South sea pearl in Australian Indian ocean .
Cultured pearls are formed either in fresh water or salt lakes. The Keshi pearls which come from China are outcome of mistake in seeding process of cultured pearls. The most valued and exclusively cultured are the Tahitian pearls .They are black in color and shiny and cultured in areas around Cook islands and south Pacific oceans. South Sea pearls are the rarest and largest produced from the Pinctada maxima pearl oysters found in Broome area of Australia . they are also prevalent in Indonesia and Philippines.
Physical properties :
Natural pearls are nearly 100% calcium carbonate and conchiolin. It is thought that natural pearls form under a set of accidental conditions when a microscopic intruder or parasite enters a bivalve mollusk and settles inside the shell. The mollusk, irritated by the intruder, forms a pearl sac of external mantle tissue cells and secretes the calcium carbonate and conchiolin to cover the irritant. This secretion process is repeated many times, thus producing a pearl.
Cultured pearls : Cultured pearls are the response of the shell to a tissue implant. A tiny piece of mantle tissue (called a graft) from a donor shell is transplanted into a recipient shell, causing a pearl sac to form into which the tissue precipitates calcium carbonate. There are a number of methods for producing cultured pearls: using freshwater or seawater shells, transplanting the graft into the mantle or into the gonad, and adding a spherical bead as a nucleus. Most saltwater cultured pearls are grown with beads. Trade names of cultured pearls are Akoya, white or golden South sea, and black Tahitian. Most beadless cultured pearls are mantle-grown in freshwater shells in China, and are known as freshwater cultured pearls.
The preferred weight measure used for loose pearls and pearl strands is the momme. Momme is a weight measure used by the Japanese for centuries. Today, momme weight is still the standard unit of measure used by most pearl dealers to communicate with pearl producers and wholesalers. One momme corresponds to 1/1000 kan. Reluctant to give up tradition, the Japanese government formalized the kan measure in 1891 as being exactly 3.75 kilograms or 8.28 pounds. Hence, 1 momme = 3.75 grams or 3750 milligrams.
The specific gravity of oriental salt water pearls is about 2.66-2.76 while Australian variety is as high as 2.78. Toughness is good but variable, may be affected by age, dehydration and chemical bleaching during the process.
- Pearl is the gemstone representing the planet Moon in ones horoscope.
- It helps to enhance the power of moon which signifies charming eyes, healthy family life ,steady mind.
- It helps in reducing the ill effects of disturbed sleep.
- It is recommended to those who get angered easily , are indecisive and depressed.
- It increases memory and brain power.
- It also brings harmony in ones life and relationships.