Pearls are born from living creatures, oysters. However, cultivated pearls are formed by mollusc. An irritant like sand grain is forced inside the shell. This irritant is covered by the fluid excreted by mollusc which is known as nacre. The nacre contains calcium carbonate which gives the irritant a special shape and colour. Also, with colour the nacre provides a special lustre and overtone to the pearl.
Often the pearls were seen in white shade. Since decades, that was the only colour which was entertained in the pearl business. However, with time, demands for unique color pearls have increased in market by stylist. This gave birth to different shades of pearl. Some of the pearls are dyed permanently. However, some are formed with special oysters. For example, South Sea pearls appear golden in color and Tahitian pearls are black in color.
Tahitian pearls are recognized for their dark shades which are formed by the unique and large oyster, black lip. Tahitian black pearl jewelry is expensive because they are one of the extreme pearls formed naturally in darker shades, otherwise other stones like Akoya or freshwater pearls are treated or dyed through artificial process.
There are two ways of coloring pearls in black –
- First, dipping or soaking pearl into silver nitrate solution. This solution darkens the nacre on the pearl.
- Second, is exposing the pearl to gamma rays that will darken its nucleus.
Both the processes are artificial process, but they treat pearls fantastically and no one can identify if it is real color or dyed. The color remains long lasting with its lustre.
However, Tahitian pearls are expensive because they are dark naturally. Most oysters excrete nacre that is silver or glossy white. It is only black lip oyster that has a thick black band. If the pearl is formed near the band, then the irritant during the course of pearl formation suck up its coloring thereby producing darker shade. This means, to prepare a darker shade Tahitian pearl the irritant has to be closer to the band and if they are farther from the lip, then you will get a light grey pearl.
It is difficult for an inexperienced person to identify between culture dyed pearls and Tahitian pearls. Thus, buy from an authorized and reliable dealer to get the right price for right item.
