Sometimes called the Biwa Pearl, Biwi Baroque Fresh Water Pearls are one of Japan's six types of pearls. The Biwi Fresh Water Pearl is formed when Japanese pearl farmers experimented with freshwater mussels in Lake Biwi--near Kyoto, Japan. Crops of Biwi Baroque Fresh Water Pearls began appearing in the 1930s. Back then, the lake produced large quantities of the highly sought after, all-nacre Biwi Pearls and Keishi Pearls. Now the term Biwi refers to the shape and not necessarily that the Freshwater Biwi Pearl Beads are from Lake Biwi.