About Biwa Pearls

Biwa pearls were originally freshwater pearls cultured in freshwater mussels rather than oysters, from Lake Biwa in Shiga Prefecture in Honshu, Japan. These were once so dominant in the marketplace that the term was applied to all freshwater pearls, including those from China. With China now dominating the freshwater pearl market, genuine Biwa pearls from Japan are rare.

History

Before Biwa pearls, the Chinese had been producing Buddha shaped freshwater pearls since the 13th Century.

Biwa cultured pearls were first harvested commercially from Biwa Lake in Japan in the 1930s, shortly after the Japanese developed successful techniques for producing cultured saltwater pearls. Biwa pearl production in Lake Biwa peaked at six tonnes in 1971 but has now declined to negligible levels due to competition from China and pollution in Lake Biwa itself. Even though the term Biwa pearl is often used to describe any cultured freshwater pearl, a pearl sold as a Biwa in the USA legally must come from Lake Biwa.

Source

Biwa or freshwater pearls are un-nucleated

Biwa pearls were originally cultured from the freshwater mussel Hyriopsis schlegeli, native to Lake Biwa. After over harvesting and pollution decimated the lake's natural mussel population, production continued until 2006 with a hybrid between the native Japanese mussel and a similar Chinese species. Japanese pearl farmers also farmed pearls from hybrid freshwater mussels in Lake Kasumigaura but production here has ceased due to pollution.

Production Method

Lake Biwa pearls became famous because they came in natural colors

Biwa or freshwater pearls are un-nucleated, meaning that they do not have a foreign body at their core like cultured saltwater pearls. Instead of introducing a foreign body into the mussel, freshwater pearl farmers cut the mantle of a living mussel and insert a tiny piece of mantle from another mussel. This makes it produce nacre and eventually a pearl. Up to 25 pearls can be cultured in a single freshwater mussel. The process takes three years in freshwater mussels.

Description

some Biwa pearls were round, many were rice grain or irregularly shaped.

Lake Biwa pearls became famous because they came in natural colors that were not seen in saltwater pearls. Because they are un-nucleated, freshwater cultured pearls have a luminescence and lustre comparable to that of natural, uncultured pearls. While some Biwa pearls were round, many were rice grain or irregularly shaped.

Future

Pearlguide.com reports that Chinese freshwater pearl farmers have started to produce Biwa pearls from the original Biwa pearl mussel Hyriopsis schlegeli imported live from Japan. Pearl Guide also asserts that the Chinese have now crossbred the Biwa pearl mussel with native Chinese species to produce a hybrid which yields pearls of higher quality than even the original Biwa mussel.

References

• Pearl Guide: Innovation Continues in Chinese Freshwater Pearl Culture
• Public Broadcasting Service: The history of pearls