Freshwater Pearls

Mankind and pearls share a fascinating history, interlinked to chart the course of the rise and fall of great civilizations.   Ancient  Rome, Greece, the land of the great Pharaohs Egypt, the mysterious Orient from India, China and Japan all coveted the Pearl and went to great extremes to acquire this most precious of gems.  Pearls adorned women, financed military campaigns, were used as medicine and even the spirit world had to contend with the power of the pearl, to ward off their baleful influence.

As the ancient civilizations declined, the barbarian civilizations of Europe slowly reached their zenith, and the lust for pearls did not abate, it intensified so much that by the end of the 19th century, natural pearls were no more available.  Man had simply exhausted the seemingly endless nature’s bounty.  Still the demand for pearls continued and resourceful that man is, the fact that nature’s supply had dried did not deter him, he simply lent Mother Nature a helping hand and so were born cultured pearls.

Cultured pearls are identical to natural pearls in all aspects, except that they are formed by human intervention.  Natural Pearls are formed when an irritant gets lodged in the oyster and as a defense against the intruder the oyster secretes Nacre which coats the irritant in concentric layers to slowly form a pearl.  In a cultured pearl the irritant is introduced in to the oyster by human hand.  Depending on the waters in which the oysters are found cultured pearls are of two types, saltwater cultured pearls and freshwater cultured pearls.

Freshwater Cultured Pearls- History

Pearls that are cultured in non-saline fresh water, in ponds, lakes and rivers using freshwater mussels are known as cultured freshwater pearls and are produced by non-nucleation.  Unlike saltwater pearls, the nucleation is not done by a bead but by inserting mantle tissue of donor mussel into the mantle tissue of 6-12 month old mussel.  Up to 12-16 mantle tissues can be inserted into the mantle of the mussel. 

The mussel is then returned to freshwater and tended for 2-6 years till the pearl is formed.  The pearl so formed is totally Nacre and since there is no bead to guide the deposition of nacre, the freshwater pearls display an astonishing range of shapes and sizes.

The history of cultivating freshwater pearls begins in 1914 in Japan at Lake Biwa using the Biwa pearl mussel Hyriopsis Schlegel.  The Japanese freshwater pearls were so popular that they were simply referred to as Biwa pearls.  By 1970 pollution of the lake led to a decline in the production of the Biwa pearls.  In the past 10 years Lake Kasumigaura started production of freshwater pearls but it enjoyed a short life as, once again pollution of the Lake led to a decline in culturing. 

The Chinese have an even older tradition of freshwater pearl farming.  In 500 AD the ancient Chinese inserted tiny Buddha moulds in the Cockscomb freshwater mussel to create the Buddha blister pearl.  This is undeniably the first cultured freshwater production.  The culturing of these freshwater mussels led to the rice crispies, a lower grade of pearls.  Since 1980 the Chinese Triangleshell, produces freshwater pearls of the highest quality.

The production of freshwater pearls in the United States was started in 1963 in Tennessee by John Latendresse and today America enjoys a fair share of the freshwater pearl market.
The scenario of the cultured freshwater pearl market today is eclipsed by China, followed by Japan, the United States, and Tahiti.  

Freshwater Pearls- Nacre and Luster

Freshwater pearls are formed by non nucleation; the pearl is formed totally by the secretion of Nacre, which deposits in solid concentric rings. Nacre is the natural secretion of the mollusk and it alone is responsible for the iridescent glowing look of the pearl.

Nacre is composed of crystallized Calcium Carbonate and conchiolin, which is a dark colored initial secretion of the mollusk. It is the first layer deposited by the pearl sac.  Calcium carbonate consists of very thin fine platelets of aragonite.  Aragonite and conchiolin form a radial arrangement as the nacre deposits in a concentric manner. 

The translucent aragonite allows light to enter the nacre deposition and acts as a tiny prism reflecting and refracting light into myriad hues.  The thickness of the Nacre determines the quality of the pearl, the thicker the deposition more durable is the pearl.

Nacre also determines the luster of the pearl.   The iridescent brilliance of the pearl is qualified as luster and is a determining factor of the quality of a pearl.  Luster wholly depends on the nacre, its translucence, smoothness, thickness and the quantity and quality of reflected light.

Freshwater Pearls-Surface

The surface of a pearl is the first noticeable characteristic of a pearl and ideally should be smooth, clean and glowing.  But since a pearl is naturally formed by a live mollusk, perfection is not possible.  The more a pearl remains in its oyster; greater is the chance of blemishes. 

No pearl is flawless, what is necessary though is to know which flaws are acceptable and which imperfections affect the quality of the pearl.

A clean pearl has a smooth blemish-free surface with such minor imperfections that even a trained eye would be hard pressed to discover.

Lightly blemished surface implies very small irregularities, which can only be detected by a trained person.
Moderately blemished surface show flaws visible to the naked eye. Heavy blemished surface show flaws which tender the pearl valueless.

Freshwater Pearls-Shapes and Size

  • Since freshwater pearls are non-nucleated, the final pearl forms in a wide variety of shapes and sizes.
  • The shape also depends on the position of the pearl in the mollusk.
  • The three basic shapes of pearls are spherical, which is the classic, circular, perfectly round pearl.
  • Symmetrical pearls are regular and evenly balanced pearls.
  • Baroque shaped pearls are irregular and asymmetrical.
  • Based on the above classification, pearls are round, near round, oval, button, drop and semi baroque.
  • Pearl size is another determining factor of a pearl’s worth.  Pearls are measured in their diameter in millimeters.  Seed pearls are less than 1mm and most pearls are 7-7.5 mm in diameter.

Freshwater Pearls- Colors

The unique coloration of a pearl is a miracle of nature.  Freshwater pearls come in all colors of the rainbow, from the whitest white to dark grey, from lavender, tangerine, golden yellow, pale pink and peach to the rarest peacock green.  Color of a pearl is also an important factor in determining a pearl’s worth.  Pearl color is a combination of its body color and overtone. 

Body color of the pearl is its actual color of the pearl and depends on the mollusk as well as the waters in which the pearl is formed.   Overtone is the translucent color that overlaps the body color adding a sheen and shimmer to the pearl. 

Pearls are a gift of nature, coveted and held in high regard by all who are fortunate to possess it.  The industry of pearl culture has put pearls within reach of all offering its consumers a choice of saltwater as well as freshwater pearls.  Today China is the leading producer of quality freshwater pearls, offering a breathtaking range of color and shapes of pearls.