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PEARL HISTORY 
Freshwater Pearls Natural freshwater pearls occur in mussels for the same reason that saltwater pearls occur in oysters. They are both molluscs. Foreign material (usually a sharp object) enters a mussel and cannot be expelled. To reduce irritation the mollusc coats the foreign object with the same secretion it uses for shell building - nacre. To 'culture' freshwater mussels, workers slightly open their shells, cut small slits in 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 is sufficient to start nacre production. Most cultured freshwater pearls are composed entirely of nacre, just like their natural saltwater counterparts. The first freshwater pearls were cultured in Japan, following on from Japanese pearl farmer's success at saltwater cultured pearling. This was in Lake Biwa near Kyoto where the first commercial crops started in the 1930s. In recent years pollutants in this lake has severely compromised pearl farming in Japan and the Chinese moved to fill the vacuum. In the 1970s China produced what were referred to as rice krispies - oddly shaped material with a crinkly surface dyed in a number of 'pop' colours. They were inferior to Japanese Biwa freshwater pearls. In the 1980s China mastered the best in world pearling techniques and experimented with shapes and colours. Asia (mainly in China) is now in its Third Pearl Wave. Starting in the 1990's China surprised the market with products that have revolutionised pearling. The shapes lustre, and colours of the new Chinese products are now considered better than the original Biwa (Japanese) freshwater products. Bleaching, dying, polishing does occur. New nucleation techniques have produced higher quality pearls to the extent that saltwater and freshwater techniques have become indistinguishable. Some of Chinas new pearls are all nacre and all unmarked. Many gem labs have identified them as 'naturals' ! Extract from the book 'Pearls' author Fred Ward, Gemologist, Maryland USA |