A great irony of pearl history is that the least expensive cultured pearl product in the market today rivals the quality of the most expensive natural pearls ever found. The price-value anomaly is obvious to consumers as they hasten to buy Chinese freshwater bargains. Indeed, pearls from freshwater mussels lie at the center of the liveliest activity in pearling today.
Natural fresh water pearls occur in mussels for the same reason that saltwater pearls occur in oysters. Foreign material, usually a sharp object or parasite, enters a mussel and cannot be expelled. To reduce irritation, the mollusk coats the intruder with the same secretion it uses for shell-building, nacre. To culture freshwater mussels, workers slightly open their shells, cut small slits into the mantle tissue inside both shells, and insert small pieces of live mantle tissue from another mussel into those slits. In freshwater mussels that insertion alone is sufficient to start nacre production. Most cultured fresh water pearls are composed entirely of nacre, just like their natural freshwater and natural saltwater counterparts.
The Chinese were the first to culture a product from freshwater mussels, though their centuries-old Buddhas are not true pearls but shell mabes. The first cultured fresh water pearls originated in Japan. Quite soon after their initial success with cultured saltwater pearls, Japanese pearl farmers experimented with freshwater mussels in Lake Biwa, a large lake near Kyoto. Initial commercial fresh water pearl crops appeared in the 1930s. The all-nacre Biwa pearls formed in colors unseen in saltwater pearls. Almost instantly appealing, their lustre and luminescent depth rivaled naturals because they, too, were pearls throughout.
Natural fresh water pearls are seldom perfectly round or even nearly round, more often than not they are baroque, slugs, or wings. Many pearls, both natural and cultured, have beautiful color and luster. Fresh water pearls are noted for their wide range of color, they can be found in white, silvery white, pink, salmon, red, copper, bronze, brown, lavender, purple, green, blue, cream, and yellow. Although white is the most common color, the most desirable are the pastel pinks, roses, lavenders, and purples. The different colors are a function of the mussel species, genetics, water quality, and the position of the pearl in the shell. Generally, pearls assume the color of the shell in which they form. Problems can arise in putting together matched strands because of the wide range of pastel colors.
The shape of the nucleus and its position in the mussel determines the shape of the cultured pearl. The shapes recovered include rounds, pears, eggs, drops, buttons, domme, and baroques. In turn, the baroques include many recognized shapes such as, nuggets, dog tooths, wings, hammers, twins, barrels round-a-circle, and rosebuds. The baroques are becoming popular for use in the manufacture of rings, earrings, and pendants. Cultured pearls come in all of the same colors as natural pearls.
Freshwater shell and pearl mussels are from the family Unionidae, from which about 20 different species are commercially harvested. The common names of the most prolific species include the ebony, washboard, heelsplitter, pimple back, elephant ear, mapleleaf, three-ridge pigtoe, pistol grip, and butterfly. Peak commercial fishing is from April through September, when hundreds of independent divers operate in the rivers, streams, and lakes of the Eastern, Southern, and Central United States.
The ultimate size of the cultured pearl industry depends on a number of factors. The acreage of pollution free water available that is suitable for farms could decide the size of the industry. Yet, even before the limitation of available suitable water comes into play, two main factors, demand for cultured fresh water pearls and the supply, or the ability of the producers to meet this demand with acceptable goods routinely, will decide the future of the industry. Some individuals have already likened these two factors to the chicken and egg question; does the demand for the pearls come first, or does the adequate supply of acceptable goods come first. Indications are that both factors are currently complementing each other, and they are contributing to the healthy growth of the young industry.
Fresh water pearls are best known for their whimsical shapes and wide range of sizes and colors. While most fresh water pearls are typically irregularly shaped. Made of solid nacre, these pearls are sure to last a lifetime.
Pearls come in all shapes and many colors. They can be pearls formed by nature, or their formation can be "cultured," meaning it is initiated by humans. Pearls grow in salt or fresh water. This subject page will help you learn more about all types of pearls.