Fresh water cultured pearls turn up in a wider range of colors and shapes than their saltwater counterparts. You will see them in white, off-white, champagne, shades of pink and orange, purple, mauve, silver and brown. Their shapes take in oval, ovate, button-shaped, and drop shaped. Flawlessly round, large freshwater pearls are virtually nonexistent. Another dissimilarity from saltwater pearls- a single fresh water mussel can produce up to 60 pearls a year, much higher than saltwater production levels. Natural fresh water pearls come about in mussels for the identical cause that saltwater pearls occur in oysters.
An external object, such as a sand grain or tiny parasite, comes into a mussel and cannot be excreted. To relieve irritation, the mollusk coats the gatecrasher with a secretion it uses for building it's shell, called nacre. In cultured freshwater pearl production, workers ease the mussel half shells apart and cut small slits into the mantle tissue inside both shells. Then they introduce minute pieces of live tissue from a different mussel into the slits. That is enough to start nacre production. The majority of cultured freshwater pearls are made entirely of nacre, just like their natural counterparts.
Culture of fresh water pearls began in Japan. After their successes with culturing saltwater pearls, Japanese pearl farmers experimented with freshwater mussels in Lake Biwa. The early freshwater commercial crops came out in the 1930s. The all-nacre Biwa pearls featured colors never seen in saltwater pearls. Depth of luminescence and lustre matched naturals. In fact, until recently, all fresh water pearls were called "Biwas," no matter where they came from. Japan dominated the market.
Although you will still hear people talk about Biwa pearls, today's freshwater pearl production is mostly from China. Production has in Lake Biwa has ended due to pollution and excessive harvesting. In 1994 Japanese pearl farms were devastated by "red tide," a threatening influx of toxic micro-organisms that killed over 150 million pearl-producing oysters by 1996. Also in the Chinese pearl farmers favor is the many large lakes and rivers combined with an equally large cheap labor force. This change is a complete transformation in the previously stable pearl industry, and amounts to immense savings to you, the consumer.
Antoinette Boulay is a pearl jewelry fan and contributor to Pearl-Necklace.info . Don't miss her Fresh water Pearl Jewelry Tips